BAA Comet Section : Comets in 2000

Updated 2009 January 14


  • 2P/Encke
  • 9P/Tempel 1
  • 10P/Tempel 2
  • 17P/Holmes
  • 19P/Borelly
  • 29P/Schwassmann-Wachmann 1
  • 41P/Tuttle-Giacobini-Kresak
  • 47P/Ashbrook-Jackson
  • 50P/Arend
  • 59P/Kearns-Kwee
  • 63P/Wild 1
  • 73P/Schwassmann-Wachmann 3
  • 74P/Smirnova-Chernykh
  • 75P/Kohoutek
  • 84P/Giclas
  • 95P/Chiron
  • 97P/Metcalf-Brewington
  • 106P/Schuster
  • 110P/Hartley 3
  • 114P/Wiseman-Skiff
  • 141P/Machholz 2

  • 2000 A1 Montani
  • 2000 A2 SOHO
  • A/2000 AB229
  • 2000 B1 SOHO
  • 2000 B2 LINEAR
  • 2000 B3 P/LINEAR
  • 2000 B4 LINEAR
  • 2000 B5 SOHO
  • 2000 B6 SOHO
  • 2000 B7 SOHO
  • A/2000 BD19
  • 2000 C1 P/Hergenrother
  • 2000 C2 SOHO
  • 2000 C3 SOHO
  • 2000 C4 SOHO
  • 2000 C5 SOHO
  • 2000 C6 SOHO
  • 2000 CT54 LINEAR
  • 2000 D1 SOHO
  • 2000 D2 LINEAR
  • 2000 D3 SOHO
  • 2000 E1 SOHO
  • A/2000 EJ37
  • 2000 ET90 P/Kowal-Mrkos
  • 2000 EC98 (60558)
  • 2000 F1 SOHO
  • 2000 G1 P/LINEAR
  • 2000 G2 LINEAR
  • A/2000 GH147
  • A/2000 GQ132
  • 2000 H1 LINEAR
  • 2000 H2 SOHO
  • 2000 H3 SOHO
  • 2000 H4 SOHO
  • 2000 H5 SOHO
  • 2000 J1 Ferris
  • 2000 J2 SOHO
  • 2000 J3 SOHO
  • 2000 J4 SOHO
  • 2000 J5 SOHO
  • 2000 J7 SOHO
  • A/2000 HR24
  • A/2000 HD74
  • 2000 K1 LINEAR
  • 2000 K2 LINEAR
  • 2000 K3 SOHO
  • 2000 K4 SOHO
  • 2000 K5 SOHO
  • 2000 K6 SOHO
  • 2000 L1 SOHO
  • 2000 L2 SOHO
  • 2000 L3 SOHO
  • 2000 L4 SOHO
  • 2000 L5 SOHO
  • 2000 L6 SOHO
  • A/2000 LK
  • 2000 M1 SOHO
  • 2000 M2 SOHO
  • 2000 M3 SOHO
  • 2000 M4 SOHO
  • 2000 M5 SOHO
  • 2000 M6 SOHO
  • 2000 M7 SOHO
  • 2000 M8 SOHO
  • 2000 M9 SOHO
  • 2000 N3 SOHO
  • A/2000 NL10
  • 2000 O1 Koehn
  • 2000 O2 144P/Kushida
  • 2000 O3 SOHO
  • 2000 OF8 Spacewatch
  • A/2000 OO67
  • 2000 P1 SOHO
  • 2000 P2 SOHO
  • 2000 Q1 SOHO
  • 2000 QJ46 P/LINEAR
  • 2000 QD101 (P/Russell-LINEAR)
  • 2000 R1 145P/Shoemaker-Levy 5
  • 2000 R2 P/LINEAR
  • 2000 S1 P/Skiff
  • 2000 S2 P/Shoemaker-LINEAR
  • 2000 S3 LONEOS
  • 2000 S4 LINEAR-Spacewatch
  • 2000 SV74 LINEAR
  • 2000 SO253 Anderson-LINEAR
  • 2000 T1 SOHO
  • 2000 T2 P/Kushida-Muramatsu
  • 2000 T3 SOHO
  • 2000 T4 SOHO
  • 2000 U1 SOHO
  • 2000 U2 SOHO
  • 2000 U3 SOHO
  • 2000 U4 SOHO
  • 2000 U5 LINEAR
  • 2000 U6 P/Tichy
  • 2000 V1 SOHO
  • 2000 V2 SOHO
  • A/2000 VU2
  • 2000 W1 Utsunomiya-Jones
  • 2000 W2 SOHO
  • 2000 W3 SOHO
  • 2000 W4 SOHO
  • 2000 W5 SOHO
  • 2000 WM1 LINEAR
  • A/2000 WO107
  • 2000 WT168 150P/LONEOS
  • 2000 X1 SOHO
  • 2000 X2 SOHO
  • 2000 X3 SOHO
  • 2000 X4 SOHO
  • 2000 X5 SOHO
  • 2000 X6 SOHO
  • 2000 X7 SOHO
  • 2000 Y1 Tubbiolo
  • 2000 Y2 Skiff
  • 2000 Y3 Scotti
  • 2000 Y4 SOHO
  • 2000 Y5 SOHO
  • 2000 Y6 SOHO
  • 2000 Y7 SOHO
  • 2000 Y8 SOHO
  • 2000 Y9 SOHO
  • 2000 Y10 P/Mueller 4
  • 2000 YN30 (212P/NEAT)

  • When observing a comet please try to forget how bright you think the comet should be, what it was when you last viewed it, what other observers think it is or what the ephemeris says it should be.

    The equations for the light curves of comets that are currently visible use only the raw observations and should give a reasonable prediction for the current brightness. If the comet has not yet been observed or has gone from view a correction for aperture is included, so that telescopic observers should expect the comet to be fainter than given by the equation. The correction is about 0.033 per centimetre. Values for the r parameter given in square brackets [ ] are assumed. The form of the light curve is either the standard m = H0 + 5 log d + K0 log r or the linear brightening m = H0 + 5 log d + L0 abs(t - T + D0) where T is the date of perihelion, t the present and D0 an offset, if L0 is +ve the comet brightens towards perihelion and if D0 is +ve the comet is brightest prior to perihelion.

    Observations of individual comets are given below in ICQ format.


    Comet 2P/Encke. 2000 sees comet 2P/Encke's 58th observed return to perihelion since its discovery by Mechain in 1786. The orbit is quite stable, and with a period of 3.3 years apparitions repeat on a 10 year cycle. This year the comet is not particular well seen, but there are short observing windows from the Northern Hemisphere prior to perihelion, which is in September, and in the Southern Hemisphere after the comet reaches perihelion. There is some evidence for a secular fading and any observations will help confirm this. Another suggestion is that Encke has two active regions, an old one with declining activity, which operates prior to perihelion and a recently activated one present after perihelion. The comet is the progenitor of the Taurid meteor complex and may be associated with several Apollo asteroids.

    A few observers have spotted the comet in early August, estimating it at around 11th mag. Pepe Manteca imaged the comet on August 10 and August 14. The comet was visible in the SOHO C3 coronagraph, but was fainter than expected and was only 8.8 on September 7.1. It suddenly brightened on September 14 around 15:00 to 6.5.

    Observations in ICQ format , last observation 2000 October 4, updated 2000 November 22.


    Comet 9P/Tempel 1 was first observed in 1867, but was lost between 1879 and 1967 following an encounter with Jupiter in 1881 which increased the perihelion distance from 1.8 to 2.1 AU. Further encounters in 1941 and 1953 put q back to 1.5 AU and calculations by Brian Marsden allowed Elizabeth Roemer to recover it in 1967. Alternate returns are favourable, but perturbations will once again increase the perihelion distance in the middle of the next century. This return is an unfavourable one and no observations were made. It is an important comet to observe as it is a potential spacecraft target and a special request for observations has been made.

    Comet 9P/Tempel 1 is the target for the Deep Impact mission and observations are requested. It will be a very difficult target for amateur observation and may be around 17th magnitude. There were special observing efforts over the weekends of July 8/9, August 5/6 and September 2/3 and from September 26 to October 1.

    Observations in ICQ format , no observations, updated 2000 June 1.


    Comet 10P/Tempel 2 made its 20th observed return in 1999, since its discovery by William Tempel (Milan, Italy) as a 9th magnitude object in 1873. Several unfavourable returns were missed in the earlier years. The orbit is very stable, which is one reason why it is a favoured target for planned spacecraft missions. In 1983 the IRAS satellite detected an extensive dust trail behind the comet.

    Traditionally the light curve is regarded as highly asymmetric with a late turn on. There is a rapid rise in brightness as perihelion approaches, which continues more slowly for a couple more weeks after perihelion, followed by a slow decline until activity switches off. An alternative view is that the light curve is linear with a peak about a month after perihelion, which at this return occurs in early September.

    With a 5.5 year period alternate returns are favourable and this was one of them. It was closest to the Earth in July (0.65 AU).

    David Strange obtained an image of the comet on July 10. Jose Carvajal estimated it at 10.6 in 32cm L on August 5.9, but I was unable to see it with 20cm R on the same night. On Aug 10.9 Andrew Pearce and I observed it with 14x100B from just outside Penzance, Cornwall, my estimate was 8.7 (HS) and Andrew made it a little fainter. Back in Cambridge it was a very difficult object in the 0.20-m refractor, though it was observed during the IWCA. Andrew Pearce now back in Australia reports that the comet has faded to near 10th mag at the end of August. It is fading very slowly and it was still 12th mag in December.

    111 observations received give an uncorrected preliminary light curve of m = 10.4 + 5 log d + 0.0295 abs(t-T-18.1) or 6.1 + 5 log d + 29.3 log r.

    Observations in ICQ format , last observation 2000 January 30, updated 2000 August 16.


    Comet 17P/Holmes Pepe Manteca imaged this faint comet on August 10.
    Comet 19P/Borrelly Deep Space 1 is on its way to comet 19P/Borrelly.
    Comet 29P/Schwassmann-Wachmann 1 is not well placed for observation from the UK, but may be seen from locations further south once it emerges from solar conjunction. It begins the year in Scorpius and reaches opposition in the same constellation in June. It passes through Ophiuchus and into Sagittarius and is in solar conjunction in December. Unfortunately opportunities for UK observers may be limited, as its altitude does not exceed 11 from this country.

    This annual comet has frequent outbursts and over the past couple of years seems to be more often active than not, though it rarely gets brighter than 12m. It is possible that its pattern of behaviour is changing. In the first half of 1998 it was in outburst on several occasions and this also occurred in 1999. The randomly spaced outbursts may be due to a thermal heat wave propagating into the nucleus and triggering sublimation of CO inside the comet. This comet is an ideal target for those equipped with CCDs and it should be observed at every opportunity.

    Jose Aguiar reported as possibly being in outburst on July 1

    Observations in ICQ format , last observation 2000 July 1, updated 2000 November 7.


    Comet 41P/Tuttle-Giacobini-Kresak. Horace Tuttle was the first discoverer of 41P/Tuttle-Giacobini-Kresak in 1858, when he found a faint comet in Leo Minor. Nearly 50 years later, Professor M Giacobini discovered a 13m object whilst comet hunting, which was observed for a fortnight. A C D Crommelin linked the apparitions in 1928 and made predictions for future returns, but the comet wasn't recovered and it was given up as lost. In 1951, Lubor Kresak discovered a 10m comet in 25x100 binoculars whilst participating in the Skalnate Pleso Observatory's program of routine searches for comets. After further observations the comet was identified with the lost comet and a better orbit computed. At the 1973 return, which was similar to the 1907 return, it underwent a major outburst and reached 4m, before fading and then undergoing a second outburst. Alternate returns are unfavourable and this is one of them, but the comet has been observed at a few of them and it should be possible to observe it from equatorial regions in December. If it undergoes a further outburst, more widespread observation may be possible.
    Comet 47P/Ashbrook-Jackson was discovered in 1948 following an approach to Jupiter in 1945, which reduced the perihelion distance from 3.8 to 2.3 AU. Although intrinsically relatively bright, the large perihelion distance keeps it faint. Alternate returns are favourable, but this is not one of them, although the comet will be reasonably well placed for Southern Hemisphere observers at 13m.

    Michael Mattiazzo recovered the comet at 14.0 on July 4.

    7 observations received give an uncorrected preliminary light curve of m = 2.1 + 5 log d + 25.9 log r.

    Observations in ICQ format , last observation 2000 November 1, updated 2000 November 22.


    Comet 50P/Arend. At its best ever return the comet only reached 14m and this apparition was not a good one, however observations were received, but the comet was never brighter than 14th magnitude.

    Observations in ICQ format, last observation 1999 November 30, updated 2000 February 25.


    Comet 59P/Kearns-Kwee had a rather unfavourable return, but a few observations were made in January, when it was fading from a peak of around 14th magnitude in the previous autumn.

    Observations in ICQ format, last observation 2000 February 5, updated 2000 August 16.


    Comet 63P/Wild 1 Nakano reported observations made by T. Kojima, Chiyoda, on October 24.83 of this 13-year-period comet, missed at its 1986 return. These observations confirm a single-night detection at mag 22.4 by Hergenrother (1.5-m Catalina reflector) on Feb. 14. The prediction on MPC 27082 requires correction by Delta T = -0.35 day. Further details were given on MPEC 1999-V18. Kojima (0.25-m f/6.3 reflector) reported the comet at m1 = 16.5 and as diffuse without a tail on Oct. 24, at m1 = 15.9 and diffuse with condensation and a coma diameter of 30" on Nov. 4. [IAUC 7302, 1999 November 6].

    It was a difficult object of 14th mag on January 5.

    9 observations give an uncorrected preliminary light curve of 5.6 + 5 log d + [25] log r

    Observations in ICQ format, last observation 2000 March 5, updated 2000 August 16.


    Comet 73P/Schwassmann-Wachmann 3 Professor A Schwassmann and A A Wachmann of Hamburg Observatory discovered their third periodic comet, on minor planet patrol plates taken on 1930 May 2. Initially of magnitude 9.5 it brightened to nearly 6m, thanks to a very close approach to Earth (0.062 AU) on June 1. The initial orbit was a little uncertain and the comet wasn't found at this or succeeding apparitions until 1979. The comet passed within 0.9 AU of Jupiter in 1953, and 0.25 AU in 1965. In August 1979, Michael Candy reported the discovery of a comet on a plate taken by J Johnston and M Buhagiar while searching for minor planets; this had the motion expected for 73P/Schwassmann-Wachmann 3, but with perihelion 34 days later than in a prediction by Brian Marsden. Missed again at the next return, it has been seen at the last three returns. The 1930 approach to Earth is ninth on the list of well determined cometary approaches to our planet. In May 2006 it will make another close approach (0.082 AU), when it could again reach 7m or brighter. This small miss distance makes it a convenient spacecraft target, and the Contour mission is scheduled to intercept it, as well as comets 2P/Encke and 6P/d'Arrest and possibly a new discovery. Following its outburst in 1995, 73P/Schwassmann-Wachmann 3 is expected to show fresh cometary surfaces, whilst 2P/Encke is an old comet and 6P/d'Arrest an average one. With the orbit approaching so closely to the Earth, an associated meteor shower might be expected, and the comet has been linked to the Tau Herculid shower, though the radiant now lies in the Bootes - Serpens region. Strong activity was reported in 1930 by a lone Japanese observer, but little has been seen since then. It is likely that any future activity would be in the form of a short-lived outburst, confined to years when the comet is at perihelion. The comet will be brightening towards the end of the year on its way to perihelion in late January 2001. If it maintains the level of activity seen at the last return it might be glimpsed in the morning sky around the beginning of December, although the solar elongation is not good.

    A. Nakamura, Kuma, Ehime, Japan, reports that a CCD image taken low in the morning sky by K. Kadota (Ageo, Saitama, 0.18-m reflector) on Nov. 4.84 UT shows this comet unexpectedly bright at m_1 = 13.2, with coma diameter 0'.5 and a 0'.8 tail in p.a. 310 deg. [IAUC 7518, 2000 November 10]


    Comet 74P/Smirnova-Chernykh Close encounters with Jupiter in 1955 and 1963 changed the orbit drastically and it was discovered in 1975, though it had been earlier given the minor planet designation 1967 EU. For a few years around 2025 it will be captured by Jupiter and then a further encounter with the planet at the end of the century will move the perihelion distance outside that of Jupiter. Due to the low eccentricity of its orbit the comet is visible even at aphelion but it is faint at about mag 16. At this return it doesn't reach perihelion until January 2001. however the AGEO team are imaging it and it has reached 15th magnitude.

    12 observations give an uncorrected preliminary light curve of 3.8 + 5 log d + [15] log r

    Observations in ICQ format, last observation 2000 January 15, updated 2000 January 29.


    Comet 75P/Kohoutek may become visible in large apertures towards the end of the year.
    Comet 84P/Giclas This is the comet's fourth observed return since its discovery in 1978 by Henry Giclas of the Lowell Observatory. The perihelion distance is fairly constant at present and Jupiter encounters only make significant changes to the angular elements. However around 2300, a low velocity close encounter with Jupiter will transfer the comet to an orbit outside that of the planet.

    It reached 14th magnitude last autumn.

    Observations in ICQ format, last observation 2000 January 26, updated 2000 August 16.


    Comet/Asteroid 95P/Chiron is 16m when at opposition in early June in Libra. Maurice Gavin obtained images of the comet on 1999 July 10 and 11.

    Observations in ICQ format, last observation 1999 June 12, updated 1999 July 7.


    Comet 97P/Metcalf-Brewington G. V. Williams, Minor Planet Center, identified this comet with an asteroidal LINEAR object of 19th mag, 1.1 deg from the prediction (MPC 31663). The nominal correction is Delta(T) = +3.5 days, but lacks literal meaning because of the 1993 passage < 0.11 AU from Jupiter. [IAUC 7487, 2000 September 5]
    Comet 106P/Schuster was discovered in 1977 October at La Silla, though a month earlier it had been recorded as an asteroid. It was not seen at its second return, which was unfavourable. The orbit is relatively stable.

    This was its third observed return and it remained at 13th - 14th magnitude from late October into January.

    Observations in ICQ format, last observation 2000 February 27, updated 2000 August 16.


    Comet 110P/Hartley 3 is another comet which may become visible in large apertures towards the end of the year.
    Comet 114P/Wiseman-Skiff is near peak brightness. On December 7.8 I made it 14.0: in the Northumberland, but it was only visible with averted vision. On January 5 I could see it clearly at 14th mag.

    29 observations received give an uncorrected preliminary light curve of 9.7 + 5 log d + [25] log r

    Observations in ICQ format, last observation 2000 February 27, updated 2000 May 29.


    Comet 1999 P1 141P/Machholz 2 This periodic comet was predicted to be the brightest in 1999, though it didn't live up to expectation and only reached 10th magnitude.

    Donald Machholz discovered P/Machholz 2 (1994 P1) with his 0.25-m reflector at 10m in August 1994. It proved to have multiple components, first reported by Michael Jager (Vienna, Austria). The four secondary components could all be described by the same orbit, but with perihelion delayed by up to half a day from the primary. At times there seemed to be a faint trail of material linking the components. The comet has a short period of 5.2 years with a perihelion distance of 0.75 AU and aphelion just inside the orbit of Jupiter. The orbit has been slowly evolving, with progressive changes occurring about every 50 years, thanks to approaches to Jupiter. The most recent close approach was in 1982. With a relatively stable perihelion distance, which is slowly increasing, it is perhaps surprising that the comet was not discovered earlier. There was a favourable return in autumn 1978 when it might have reached 8th magnitude and very favourable returns in the autumns of 1920, 1937 and 1957 when it might have reached 6th magnitude. The fact that it was not discovered at any of these returns suggests either that the orbital evolution is slightly inaccurate, or that the absolute magnitude at the 1994 return was not typical. At present the earth passes about 0.25 AU outside the descending node and the orbital evolution will slowly decrease this distance, raising the possibility of meteor shower from the comet in a few hundred years time.

    Robert H. McNaught recovered component A of the comet on CCD images obtained with the 1.0-m f/8 reflector at Siding Spring on 1999 August 3.55.

    This return was moderately favourable with the comet moving rapidly eastwards, through Aquarius, Cetus, Eridanus and Orion as it fades. The A component brightened significantly in the last week of 1999 and is now around 10th mag, though it is beginning to fade and become more diffuse. The D component is several magnitudes fainter and is unlikely to be seen. The comet is still several magnitudes fainter than expected. Martin Mobberley imaged the comet on December 29.75. and January 9 . David Strange also imaged it on January 9 . Visually it is a rather diffuse object and I made it 9.7 in my 0.33-m Dobsonian on January 9.74. By mid February it is unlikely to be observable.

    42 observations give an uncorrected preliminary light curve of m = 11.7 + 5 log d + 0.0511 abs(t-T-20.6).

    Observations in ICQ format , Last observation 2000 February 8, updated 2000 August 16.


    SOHO Kreutz group comets
    2000 A2 SOHO (IAUC 7562, 2001 January 14)
    2000 B1 SOHO (IAUC 7349, 2000 January 24)
    2000 B5 SOHO (IAUC 7386, 2000 March 24)
    2000 B6 SOHO (IAUC 7386, 2000 March 24)
    2000 B7 SOHO (IAUC 7386, 2000 March 24)
    2000 C6 SOHO (IAUC 7364, 2000 February 12)
    2000 D1 SOHO (IAUC 7370, 2000 February 29)
    2000 D3 SOHO (IAUC 7386, 2000 March 24)
    2000 E1 SOHO (IAUC 7376, 2000 March 07)
    2000 F1 SOHO (IAUC 7393, 2000 April 04)
    2000 H2 SOHO (IAUC 7412, 2000 May 01)
    2000 H3 SOHO (IAUC 7572, 2001 January 25)
    2000 H4 SOHO (IAUC 7572, 2001 January 25)
    2000 H5 SOHO (IAUC 7572, 2001 January 25)
    2000 J3 SOHO (IAUC 7422, 2000 May 11)
    2000 J4 SOHO (IAUC 7426, 2000 May 19)
    2000 J5 SOHO (IAUC 7433, 2000 May 30)
    2000 J6 SOHO (IAUC 7567, 2001 January 19)
    2000 J7 SOHO (IAUC 7572, 2001 January 25)
    2000 K3 SOHO (IAUC 7433, 2000 May 30)
    2000 K4 SOHO (IAUC 7433, 2000 May 30)
    2000 K5 SOHO (IAUC 7433, 2000 May 30)
    2000 K6 SOHO (IAUC 7433, 2000 May 30)
    2000 K7 SOHO (IAUC 7567, 2001 January 19)
    2000 K8 SOHO (IAUC 7567, 2001 January 19)
    2000 L1 SOHO (IAUC 7439, 2000 June 14)
    2000 L2 SOHO (IAUC 7439, 2000 June 14)
    2000 L3 SOHO (IAUC 7439, 2000 June 14)
    2000 L4 SOHO (IAUC 7445, 2000 June 29)
    2000 L5 SOHO (IAUC 7445, 2000 June 29)
    2000 L6 SOHO (IAUC 7572, 2001 January 25)
    2000 M1 SOHO (IAUC 7445, 2000 June 29)
    2000 M2 SOHO (IAUC 7450, 2000 July 08)
    2000 M3 SOHO (IAUC 7452, 2000 July 11)
    2000 M4 SOHO (IAUC 7452, 2000 July 11)
    2000 M5 SOHO (IAUC 7452, 2000 July 11)
    2000 M6 SOHO (IAUC 7453, 2000 July 13)
    2000 M7 SOHO (IAUC 7453, 2000 July 13)
    2000 M8 SOHO (IAUC 7453, 2000 July 13)
    2000 M9 SOHO (IAUC 7454, 2000 July 14)
    2000 N1 SOHO (IAUC 7454, 2000 July 14)
    2000 N2 SOHO (IAUC 7459, 2000 July 20)
    2000 N3 SOHO (IAUC 7572, 2000 January 25)
    2000 P1 SOHO (IAUC 7479, 2000 August 21)
    2000 P2 SOHO (IAUC 7479, 2000 August 21)
    2000 T1 SOHO (IAUC 7506, 2000 October 10)
    2000 T3 SOHO (IAUC 7508, 2000 October 16)
    2000 T4 SOHO (IAUC 7508, 2000 October 16)
    2000 U1 SOHO (IAUC 7514, 2000 November 1)
    2000 U2 SOHO (IAUC 7514, 2000 November 1)
    2000 U3 SOHO (IAUC 7514, 2000 November 1)
    2000 U4 SOHO (IAUC 7514, 2000 November 1)
    2000 V1 SOHO (IAUC 7520, 2000 November 17)
    2000 V2 SOHO (IAUC 7520, 2000 November 17)
    2000 W2 SOHO (IAUC 7548, 2000 December 23)
    2000 W3 SOHO (IAUC 7548, 2000 December 23)
    2000 W4 SOHO (IAUC 7562, 2001 January 14)
    2000 W5 SOHO (IAUC 7562, 2001 January 14)
    2000 X1 SOHO (IAUC 7562, 2001 January 14)
    2000 X2 SOHO (IAUC 7562, 2001 January 14)
    2000 X3 SOHO (IAUC 7562, 2001 January 14)
    2000 X4 SOHO (IAUC 7562, 2001 January 14)
    2000 X5 SOHO (IAUC 7562, 2001 January 14)
    2000 X6 SOHO (IAUC 7562, 2001 January 14)
    2000 X7 SOHO (IAUC 7562, 2001 January 14)
    2000 Y4 SOHO (IAUC 7562, 2001 January 14)
    2000 Y5 SOHO (IAUC 7567, 2001 January 19)
    2000 Y8 SOHO (IAUC 7567, 2001 January 19)
    2000 Y9 SOHO (IAUC 7567, 2001 January 19)
    were discovered with the SOHO LASCO coronographs and have not been observed elsewhere. They were sungrazing comets of the Kreutz group and were not expected to survive perihelion. Some of these comets show no tail at all and it is possible that some supposed observations of Vulcan were actually tiny Kreutz group comets. Details of the Kreutz comets discovered or announced this year are now listed here, with an abbreviated list here.
    2000 A1 Montani J. Montani, Lunar and Planetary Laboratory, reported his discovery of a faint 19th mag comet on CCD images taken with the 0.90-m Spacewatch telescope at Kitt Peak on January 12.33. The comet shows a coma with diameter 5"-6", slightly elongated in p.a. 245-250 deg. An R CCD image taken by S. Kern with the 2.3-m Steward telescope on January 13 shows the comet to be clearly extended toward the southwest, and she derived mag 18.1. W. Shook found the object to be nonstellar with a 2".6 tail toward the southwest on an image taken with the 3.5-m WIYN telescope on January 13. [IAUC 7346, 2000 January 14] The comet is very distant (9.8 AU) and close to perihelion. The perihelion distance is the largest on record for a confirmed comet, though note for example TNO 1999 DP8.
    A/2000 AB229 Details of an unusual asteroid with a 400 year period, a high inclination orbit and a perihelion distance of 2.3 AU were given on MPEC 2000-B20. The 18th magnitude object was discovered by LINEAR on January 5.38 and was just past perihelion. The next MPEC gives details of another unusual object 2000 AC229, which has a period of 8.8 years, an inclination of 53 degrees and a perihelion distance of 1.8 AU. This was discovered by LINEAR on January 8.24.
    2000 B2 LINEAR A 19th mag object with unusual motion and reported as asteroidal by LINEAR on January 29.24 has been found to be cometary in appearance following posting on the NEO Confirmation Page. CCD observations by P. Kusnirak (Ondrejov, 0.65-m f/3.6 reflector) and by M. Tichy and Z. Moravec (Klet, 0.57-m f/5.2 reflector) indicate that the object appears slightly diffuse. [IAUC 7354, 2000 February 1] The comet is a distant one, past perihelion and will fade.
    2000 B3 P/LINEAR A 19th magnitude object with unusual motion that was reported as asteroidal by LINEAR on January 27.24 has been found to be cometary in appearance following posting on the NEO Confirmation Page. CCD observations by P. Kusnirak (Ondrejov, 0.65-m f/3.6 reflector) on Feb. 1 show a coma diameter of 6" and a faint tail in p.a. 120 deg, and F. Zoltowski (Edgewood, NM, 0.3-m f/3.3 reflector) reports a small faint tail about 30" long in p.a. 100 deg and a dense coma about 10" across. The comet is near perihelion. [IAUC 7356, 2000 February 2]
    2000 B4 LINEAR Another apparently asteroidal object, of 19th mag, was reported by LINEAR on January 29.25 and posted on the NEO Confirmation Page. This object has the orbit of a centaur and was noted as appearing perhaps slightly diffuse (P. Kusnirak, Ondrejov, 0.65-m reflector, Feb. 10) and 'soft' and slightly larger than star images (D. Balam, Victoria, 1.82-m reflector, Feb. 11). The perihelion distance is 6.8 AU and the period 77 years [IAUC 7368, 2000 February 18]
    A/2000 BD19 MPEC 2000-C09 reports the discovery by LINEAR of a sungrazing asteroid on January 26.26. The 18th mag object has a period of 0.8 years, and a perihelion distance of 0.09 AU. If entirely asteroidal it would be 12th mag at perihelion, but if it shows cometary activity it could reach 6th and be visible on SOHO LASCO images. It was last at perihelion on 1999 Oct 17.3 and will next be at perihelion in 2000 August.
    2000 C1 P/Hergenrother Carl Hergenrother, Lunar and Planetary Laboratory, reported a 17th mag object on 2000 February 4.46 that showed an 11" tail in p.a. 300 deg on one of four CCD images taken with the 0.41-m Schmidt telescope at Catalina. Following posting on The NEO Confirmation Page, numerous CCD observers reported cometary appearance: Feb. 5.3 UT, coma diameter about 12", brighter 60" tail in p.a. 290 deg, extending more faintly to 180" (J. E. McGaha, Tucson, AZ, 0.62-m reflector); Feb. 5.5, tail about 12" long toward the northwest (G. Billings, Calgary, AB, 0.36-m reflector); Feb. 5.7, slightly diffuse with very faint tail about 10" long to the northwest (G. J. Garradd, Loomberah, N.S.W., 0.45-m reflector); Feb. 6.1, coma diameter 0'.1, tail 0'.3 long in p.a. 290 deg (P. Pravec and P. Kusnirak, Ondrejov, 0.65-m reflector); Feb. 6.4, faint tail < 10" long in p.a. about 290 deg (D. T. Durig, Sewanne, TN). Prediscovery observations by LINEAR on Jan. 4 and 8 have also been identified. [IAUC 7357, 2000 February 6] The comet is intrinsically quite faint and has perihelion at 2 AU. It will brighten a little.
    2000 C2 SOHO, 2000 C3 SOHO, 2000 C4 SOHO, 2000 C5 SOHO and 2000 C6 SOHO D. A. Biesecker, SM&A Corporation and Goddard Space Flight Center, reports measurements of five comets observed with the coronagraphs aboard SOHO. Only C/2000 C6 appears to be a Kreutz sungrazer; it was first noticed by Terry Lovejoy on SOHO web images on February 9.22, and Biesecker notes that its brightness ranged from V = 8.7 on February 9.43 to 7.7 on February 9.68 UT, and the comet showed a tail at 13 solar radii on C3 images. The other comets showed no tail. C/2000 C2 (SOHO's 100th comet) first noted by Kazimieras Cernis on February 3.70, remained relatively stable in brightness (V = 6.5-6.9) during February 3.70-3.84. C/2000 C3, found by Biesecker on February 4.56, brightened from V = 6.7 on February 4.59 to 5.9 on February 4.79, before fading to V = 7.0 on February 5.09. C/2000 C4, found by Maik Meyer on February 5.16, was on a trajectory closely following that of C/2000 C3, and it was assumed that the orbits are identical with a difference Delta(T) = 0.60 day. C/2000 C4 brightened from V = 5.9 on February 5.17 to 4.9 on February 5.30, before fading to V = 6.7 on February 5.67. C/2000 C5, found by Michael Oates on February 7.79, was at V = 7.5-8.0 on February 7. Comets C/2000 C2 and C/2000 C5 may also be related to each other. [IAUC 7364, 2000 February 12]
    2000 CT54 LINEAR Yet another apparently asteroidal LINEAR object, of 19th mag, discovered on February 2.44, that was posted on the NEO Confirmation Page was noted to have a 15"-16" tail toward the north-northwest on February 12 by J. G. Ries, McDonald Observatory (0.76-m reflector). The comet reaches perihelion at 3.1 AU in 2001 June [IAUC 7368, 2000 February 18]

    Observations in ICQ format, no positive observations, updated 2001 July 24.


    2000 D2 LINEAR An apparently asteroidal object of 18th mag, discovered by LINEAR on February 25.20 and posted on the NEO Confirmation Page has been observed to be cometary by F. B. Zoltowski (Edgewood, NM; very diffuse image on February 28.1 UT; 12" tail in p.a. 270 deg on March 1.1) and by C. Hergenrother (Catalina 1.54-m reflector; 8" coma and very faint 15" tail in p.a. 105 deg on March 1.3). The comet was near perihelion at 2.3 AU. [IAUC 7372, 2000 March 1]
    A/2000 EJ37 This asteroid is in a typical short period comet orbit, with period of 10 years and a perihelion distance of 1.4 AU. It was last at perihelion in early January 2001.
    2000 ET90 P/Kowal-Mrkos MPS 11479 contains observations on March 9.30 and 13 by LINEAR of an apparently asteroidal, 19th magnitude object presumed to have a moderately eccentric orbit in the inner part of the main belt. Linkage by G. V. Williams to LINEAR observations on April 4 and 8 demonstrated the cometary nature of the orbit, and the object was placed in The NEO Confirmation Page. Isolated observations from LINEAR on February 7, from the Catalina Sky Survey on March 1 (when observer T. B. Spahr had in fact drawn attention to the object's "slowish" motion) and from LONEOS on April 2 were then also linked. Neither these observers nor those responding to the Confirmation Page made a definite remark about the object's cometary appearance, even in response to specific enquiries from the Central Bureau (although strong moonlight has recently been a factor). Following a suspicion by the undersigned and an independent suggestion by C. W. Hergenrother, 2000 ET90 has been definitively identified with comet D/1984 H1 = 1984 JD (Kowal-Mrkos) = 1984n (IAUC 3988, 4001) = 1984 X, for which current predictions (ICQ Comet Handbook for 2000, p. H87; OAA Comet Handbook for 2000, p. 37) require correction by Delta T about -125 days. The comet passed only 0.16 AU from Jupiter in Mar. 1989. There was an unobserved return with T = 1991 Aug. 2. [IAUC 7403, 2000 April 15] The original orbit was based on only eight observations, so it is perhaps not surprising that the prediction was somewhat in error.

    Carl Hergenrother provides a story about the recovery:

    The naming or not of recovered comets reminds me of a story. Back on 2002 [sic] March 1, Tim Spahr and I were working for the Catalina Sky Survey. He was on the Catalina schmidt surveying for NEOs while I was next door at the Catalina 1.5-m doing my usual comet and asteroid observations.

    During the course of the night, Tim would send me interesting objects to observe including a few objects that moved at rates indicative of high eccentricity and hence might be comets. I observed all of them but one which was low in the west. For some reason, we didn't follow it up the next night.

    A month later LINEAR finds an object that is linked to a previously designated LINEAR find from March, 2000 ET90. The object is placed on the NEOCP since it has an obvious cometary orbit. Tim noted that the object is one and the same with his suspected comet candidate which I failed to observe.

    Feeling bad for Tim and Catalina and for handing LINEAR yet another comet, I tried to find a way to prevent LINEAR from getting this one. I produced an orbit from the published astrometry and the NEOCP ephemeris. A quick search showed 2000 ET90 to be a return of Comet Kowal-Mrkos. Since an announcement had not been made yet, the ID prevented the LINEAR name from being attached to Kowal-Mrkos. So sometimes IDs are made out of spite. :)

    Of course, even if I had observed it with the 1.5-m it probably would not have made a difference. There were some big scopes looking at 143P that apparition and no one observed any cometary activity, as far as I know. So I doubt we would have been able to say it was a comet. It's cometary nature was based solely on the orbit at the time.


    2000 EC98 (60558)
    A cometary coma was detected around the centaur asteroid (60558) 2000 EC98 on 2005 December 30.50. At discovery by Spacewatch in 2000 the object was 21st magnitude, but the development of a coma has caused it to brighten by at least 3 magnitudes. Visual reports suggest it could be even brighter, and Seiichi Yoshida reports it at 14.4, with a 0.5' coma and DC3 in his 0.4m reflector on January 8.78. He suggests that this may be the most distant visual detection of a comet, as the object is 13 AU from the Sun. The object is in a 35 year orbit, and not due to reach perihelion until 2015, when it will be at 5.9 AU.

    The case seems similar to that of Chiron, which is (2060) 95P/Chiron, so the object should receive a cometary number. Roll on comet Pluto!


    2000 G1 P/LINEAR F. Shelly, for the Lincoln Near-Earth Asteroid Research project, reports, in connection with the discovery on April 7.45 of a fast-moving 18th mag object, that Lisa Brown-Manguso noticed that the object showed clear cometary activity. [IAUC 7396, 2000 April 8] Subsequent observations confirmed that it is a periodic comet, with a perihelion distance of 1.003 AU and perihelion on March 9.8. The period is 5.4 years. The comet passed only 0.10 AU from Earth in late February and early March, when it could have reached 14th mag, but was at high southern declination. It is intrinsically very faint.

    The comet was moved into its present orbit in February 1987 when an encounter to within 0.15 AU of Jupiter made significant changes to the elements.

    The comet could potentially have an associated meteor shower. This would be maximum around March 30 and the meteors would appear to radiate from 5h 08m -16.


    2000 G2 LINEAR Another 18th magnitude object with unusual motion that was reported as asteroidal by LINEAR on April 4.39 has been noted by other observers, following posting on the NEO Confirmation Page, as being cometary in appearance. G. Hug, Eskridge, KS, reported a diffuse appearance on several CCD images taken with a 0.3-m reflector during Apr. 21-29, and Klet CCD observations by J. Ticha, M. Tichy, and Z. Moravec (0.57-m reflector) indicated a coma diameter of about 6" on Apr. 22.9 UT. A 300-s R exposure taken by C. Hergenrother with the Steward Observatory 2.3-m telescope on Apr. 30 confirms that this object has a 6" coma and a 20" tail in p.a. 117 deg. The comet reached perihelion on 2000 February 6.1 with a perihelion distance of 2.72 AU. [IAUC 7411, 2000 May 1]
    A/2000 GH147 The asteroid 2000 GH147 was discovered with NEAT on 12 April 2000. It was subsequently followed up by many observers worldwide, including J. Ticha, M. Tichy at Klet, P. Kusnirak at Ondrejov, M. Hicks, D. Deaver, at Table Mountain. This 1.5 km (1 mile) asteroid is unusual with a high-inclination (50 degrees), high-eccentricity (0.48) orbit that takes it from near Mars' orbit to inside Jupiter's. It is therefore an extinct comet candidate. [NEAT web page]
    A/2000 GQ132 MPEC-2000-J19 reported a second cometary asteroid discovered by NEAT on April 12.51. This object of 18th mag is in a 5.9 year orbit with inclination of 30 degrees and a perihelion distance of 1.5 AU. [2000 May 06]
    2000 H1 LINEAR A 19th mag object reported by LINEAR on 2000 April 26.39 and posted on the NEO Confirmation Page has been noted to be diffuse at Klet (Apr. 27.0 UT), Ondrejov (Apr. 27.1), and Modra (Apr. 29.0). M. Hicks (Table Mountain Observatory) reported a 7" central condensation and 20" tail in p.a. about 120 deg on Apr. 29.4. [IAUC 7410, 2000 April 29] The comet is in a distant parabolic orbit and is just past perihelion.
    2000 J1 Ferris An apparently asteroidal object of 19th mag reported by LONEOS (observer W. D. Ferris, measurer B. W. Koehn) on May 4.32 that was posted on the NEO Confirmation Page has been found to have a faint 10" tail in p.a. 150 deg (mag R = 19.6 in a 5" aperture) on CCD images taken by M. Hicks with the Kitt Peak 2.13-m reflector on May 8.3 UT. [IAUC 7416, 2000 May 8] The object will fade.
    2000 J2 SOHO D. A. Biesecker, Emergent Information Technologies, Inc., and Goddard Space Flight Center, reports observations of another comet found in LASCO C2 data on May 7.24 by M. Oates via the SOHO website. The comet brightened from V = 7.8 on May 7.254 UT to 7.1 on May 7.368, but had faded to V = 8.3 on May 7.452, and it was not seen in the C3 instrument. No tail was evident. Astrometry (measured by Biesecker, reduced by B. G. Marsden) and orbital elements appear on MPEC 2000-J32; this comet is evidently not a Kreutz sungrazer.
    A/2000 HR24 Details of unusual asteroid 2000 HR24=1995 XH5 appear on MPEC 2000-J50. The object was first spotted by Spacewatch in December 1995, and then independently discovered by LONEOS in late April this year. Prediscovery images have been found in LINEAR and NEAT data. The asteroid has an 11.1 year period, with a perihelion distance of 4.1 AU and passed 0.76 AU from Jupiter in 1941 August. The 18th mag object, which appears stellar, will fade. [MPEC 2000-J50, 2000 May 13] The encounter with Jupiter made relatively small changes to the orbit.
    A/2000 HD74 Details of unusual asteroid 2000 HD74 appear on MPEC 2000-J56. The object has a high inclination short-period (5 year) cometary type orbit, but shows no cometary activity. The 18th mag object was discovered by LONEOS on April 30.38. It is closest to earth towards the end of this month, and reaches perihelion at 1.19 AU in July when it will be at a high southern declination. [MPEC 2000-J56, 2000 May 15]
    2000 K1 LINEAR F. Shelly, Lincoln Laboratory, Massachusetts Institute of Technology, reported that LINEAR discovered a comet (LINEAR-47), of 18th mag on May 26.31. [IAUC 7430, 2000 May 26] The comet is a distant one and will fade, though it could be several magnitudes brighter to visual observers than its discovery magnitude indicates. The comet was linked to asteroids LW24 and NF13 observed by LINEAR in 1999 and a new hyperbolic orbit is given on MPEC 2000-K29.

    Observations in ICQ format, last observation 2000 August 27, updated 2000 November 22.


    2000 K2 LINEAR Shelly also reported that LINEAR discovered another comet (LINEAR-48) on the same night. It was a little brighter and showed a tail in p.a. 240 deg. Ticha reported the comet to be slightly diffuse, and Kusnirak reports a faint tail about 20" long in p.a. 220 deg; Galad reported cometary appearance. [IAUC 7430, 2000 May 26]. The comet will brighten a little.

    Observations in ICQ format , last observation 2000 September 30, updated 2000 November 22.


    A/2000 LK Another interesting asteroid was reported on MPEC 2000-L14. Discovered by LONEOS, this object has a perihelion distance of 0.11 AU and an eccentricity of 0.95, which takes it out nearly to Jupiter's orbit.
    A/2000 NL10 This asteroid approaches the sun to 0.17 AU and has an eccentric orbit which takes it out to 1.68 AU. It was discovered by LINEAR on July 10 [MPEC 2000-N28, 2000 July 12]. Further observations from Paolmar from 1952 and 1992 have been discovered and an improved orbit is given on MPEC 2000-O17 [2000 July 23]
    2000 O1 Koehn B. W. Koehn, Lowell Observatory, reported his discovery of a possible 18th mag comet in the course of the Lowell Observatory Near-Earth-Object Survey on July 20.36. The comet is a distant one and won't become brighter than 17th mag [IAUC 7462, 2000 July 23] MPEC 2000-O22 shows the identification, by B. G. Marsden, of this comet with the LINEAR "asteroidal" objects 1998 XA_70 and 1999 UJ_10, together with improved orbital elements: T = 2000 Jan. 27.35 TT, Peri. = 55.11 deg, Node = 88.86 deg, i = 148.10 deg (equinox 2000.0), q = 5.9219 AU, e = 1.0009. [IAUC 7465, 2000 July 25]
    2000 O2 P/Kushida C. E. Delahodde, European Southern Observatory, reports the recovery by O. R. Hainaut and herself of comet P/1994 A1 (= 1994a = 1993 XX) with the 3.6-m reflector on July 25.33. The indicated correction to the prediction by S. Nakano on MPC 31664 is Delta(T) = -0.10 day. Further observations and improved orbital elements are given on MPEC 2000-O32. [IAUC 7467, 2000 July 27]
    2000 O3 SOHO I discovered another comet at 10:45 (UT) on July 31. I had given a lecture in the centre of Cambridge and didn't get into the office until after 10:00 (11:00 BST). First I checked the emails, including several Antarctic ones which had data that needed processing. Then I had a look at various web pages, including the latest MPECs, finally I had a look at the SOHO real time movies. I first looked at C2; there were no obvious Kreutz objects but I noted something that appeared to be moving opposite to the stars. I quickly found that it was moving consistently and emailed Doug and the group with details of the possible object. I then checked C3 in case it was visible and downloaded the real-time gif images to measure the positions. I found that it came into view at 21:30 on July 30 and was visible until 03:30 on July 31, moving horizontally from right to left just above the level of the occulting disc and below the beehive cluster. At its brightest (00:06) it was around 7th mag. I think the biggest surprise is that no-one else had picked up this object! Subsequently the comet came into view again, on images from 05:54 till after 12:00. The apparent fading around 03:30 may be due to phase effects playing a part. If it was then between us and the sun it would have zero phase and be difficult to see. The phase effect partly explains why many Kreutz comets are seen during May as this is when they are on the far side of the Sun and fully illuminated.

    The orbit was finally published on MPEC 2000-Q09 [2000 August 19], after Brian Marsden returned to the USA following the IAU meeting in Manchester. It seems that the IAU had commanded all three senior members of the CBAT to attend the meeting. The comet had been at perihelion on July 30.94 at a perihelion distance of 0.054 AU. Potentially observable from the ground it is at an elongation of 50 degrees in late August, though at a magnitude of near 20. The orbit shows that it passed on the far side of the sun, so phase effects do not explain the fading.

    Further to IAUC 7472, D. Hammer has provided measurements of a comet detected by the SOHO C2 and C3 instruments and found by J. D. Shanklin via the SOHO website. The reduced measurements and orbits by B. G. Marsden, together with a search ephemeris, are given on MPEC 2000-Q09. G. J. Garradd, Loomberah, N.S.W., reports that his search for this object around Aug. 21.4 UT, out to about 0.5 deg ahead of its predicted position, yielding nothing to mag about 18. [IAUC 7479, 2000 August 21]

         2000 UT           R.A. (2000) Decl.        MPEC
         July 30.221       8 21.5      +19 08       2000-Q09
    

    2000 OF8 Spacewatch Details of an unusual asteroid with a 190 year period, a high inclination orbit and a perihelion distance of 2.0 AU were given on MPEC 2000-P03. The 20th magnitude object was discovered by Spacewatch on July 24.32 and won't reach perihelion until next year. It is currently 4.4 AU from the Sun and it is possible that it will develop cometary activity as it gets closer. Further observations did indeed show cometary activity and a parabolic orbit was published on MPEC 2000-Q43. The comet reaches perihelion in August 2001 at 2.2 AU. The comet could reach 14th mag next summer. An improved hyperbolic orbit published on MPEC 2001-H34 [2001 April 24] gives 1/a (orig) as 0.000047, showing that the comet is a new one from the Oort cloud.

    Observations in ICQ format, no positive observations, updated 2001 July 11.


    A/2000 OO67 ( A revised orbit for this faint 22nd mag asteroid, discovered at Cerro Tololo with the 4-m Blanco reflector on July 29.28, appears on MPEC 2001-P43 (August 14). It has a 13,000 year periodic orbit, with perihelion at 21 AU and aphelion at over 1000 AU.
    2000 Q1 SOHO James Danaher discovered a faint non Kreutz object on C3 images from August 28. It tracked diagonaly across the upper left quadrant. The orbit published on MPEC 2000-Q42 suggests that it could be visible from the ground, but will be a very faint southern hemisphere object.
    2000 QJ46 (P/LINEAR)
    A 19th magnitude asteroid found by LINEAR on 2000 August 24.27 was found in October 2005 to show a coma and tail on archival Sloan Digital Sky Survey images taken just over a week later. The comet has a 14.4 year period, with perihelion at 1.93 AU in 2000 December.
    2000 QD101 (156P/Russell-LINEAR) IAUC 8118 (2003 April 19) announced the linkage of a comet discovered on UK Schmidt plates in September 1986, with an asteroid found at the end of August 2000 by LINEAR. Although it only appeared cometary in 1986, the identity is secure. Calculations by Kenji Muraoka show that the perihelion distance has been decreasing over the last 100 years, with significant changes around 1934 and 1970. The next significant change will be around 2017, when the perihelion distance will reduce to 1.33 AU from its present 1.60 AU.

    R. H. McNaught, Siding Spring Observatory, reports observations of a comet found in Sept. 1986 by K. S. Russell on a 90-min exposure taken by F. G. Watson earlier that month with the U.K. Schmidt Telescope. Unsuccessful attempts were made by Russell, and later by McNaught, to locate the comet on the 30-min follow-up exposure by M. Hartley obtained on Sept. 25. T. B. Spahr, Minor Planet Center, has recently identified the comet with 2000 QD_181, an apparently asteroidal object observed by LINEAR on 2000 Aug. 31 and Sept. 5 (cf. MPS 18353), and itself linked by Spahr (MPO 9348) to another LINEAR discovery 2000 XV_43 (observations Nov. 2000-Jan. 2001 on MPS 23109 and 25364), as well as to 1993 WU, recorded by C. S. Shoemaker et al. with the 0.46-m Palomar Schmidt telescope on 1993 Nov. 19 and 20 (MPS 397), the appearance again being evidently asteroidal. With the knowledge of the clearly cometary orbit, McNaught and M. A. Read have now located and measured the object on the Hartley follow-up plate. The 1986 observations were given the designation P/1986 R1. [IAUC 8118, 2003 April 19]

    Comet P/2000 QD_181 = 2000 XV_43 = 1986 R1 = 1993 WU (Russell- LINEAR), announced on IAUC 8118, has been given the permanent number 156P (MPC 48317). [IAUC 8128, 2003 May 3]


    2000 R1 P/Shoemaker-Levy 5 The LINEAR team reported that one of their objects observed on Sept. 6 was cometary, and T. Spahr and Dan Green noted that this was about 0.6 deg northwest of the prediction for P/1991 T1 = 1991z = 1991 XXII (MPC 29882, 39661), corresponding to Delta(T) = -1.4 day. Following a request from the Central Bureau, D. Balam reported that images taken with the 1.82-m Plaskett telescope of the National Research Council of Canada show this object to have a well-condensed coma and a fan-shaped tail extending 30" in p.a. 250 deg; his R magnitude of 18? was obtained in a 10" aperture. [IAUC 7488, 2000 September 7] The 18th mag object will brighten a little.
    2000 R2 P/LINEAR A 19th mag object reported as asteroidal by the LINEAR team on September 3.15, and subsequently posted on the NEO Confirmation Page, has been reported as cometary in appearance on various CCD exposures: Sept. 7.2 UT, condensed 9" coma (D. Balam, Victoria, 1.82-m reflector); Sept. 7.9, object seemed diffuse with a faint east-west tail about 10" long (M. Tichy, Klet, 0.57-m reflector); Sept. 18.51, near- stellar condensation with a fairly narrow 40" tail in p.a. 90 deg (R. H. McNaught, Siding Spring, 1.0-m reflector + 100-s R frames). The available astrometric observations are given on MPEC 2000-S04, where orbital elements show this to be a short-period comet with perihelion distance of 1.39 AU and period of 6.26 years. It has a very faint absolute magnitude of 18.0 [IAUC 7492, 2000 September 18]

    An encounter with Jupiter in November 2003 makes significant changes to the angular elements and pushes q out to 1.46 AU. Subsequent enounters will further increase q.


    2000 S1 P/Skiff B. W. Koehn, Lowell Observatory, reports the discovery by Brian A. Skiff of a comet on images from September 24.30 taken in the course of the LONEOS program. [IAUC 7496, 2000 September 25] Prediscovery observations made by LINEAR on August 26, together with additional astrometry on September 26, are given on MPEC 2000-S60 and show that the comet is periodic with a period of 17.1 years. [IAUC 7497, 2000 September 27] The comet is reported as around 15th mag, but may be brighter visually. It is near opposition in Cetus and will fade.

    Observations in ICQ format , last observation 2000 September 27, updated 2000 November 22.


    2000 S2 P/Shoemaker-LINEAR F. Shelly and R. Huber, MIT Lincoln Laboratory, reported the discovery by LINEAR of a 19th mag comet with a tail in p.a. about 280 deg, on September 27.44. Confirmation of cometary appearance on September 29.1 was received from P. Pravec and P. Kusnirak at Ondrejov (coma diameter 0'.2 with a 0'.2 tail in p.a. 260 deg) and from J. Ticha and M. Tichy at Klet (object diffuse with 14'' tail in p.a. 265 deg). Available astrometry and preliminary parabolic orbital elements (T = 2000 July 27.6 TT, q = 1.305 AU, i = 20.2 deg) were published on MPEC 2000-S67. [IAUC 7498, 2000 September 29] S. Nakano, Sumoto, Japan, then identified comet C/2000 S2 with comet D/1984 W1 (Shoemaker 2), the comet now being off from his prediction (cf. ICQ 2000 Comet Handbook) by Delta(T) = +23.2 days or about 7.5 deg in sky position. [IAUC 7499, 2000 September 29]
    2000 S3 LONEOS On October 1, B. W. Koehn communicated his measurements of a comet, later reported as discovered by B. A. Skiff on images taken on September 29.27 by M. E. Van Ness in the course of the LONEOS program at Lowell Observatory. Skiff described a nearly circular coma of diameter 15" with moderate condensation. Following tentative linkage by B. G. Marsden, Center for Astrophysics, to one (mag about 19) of about 2000 asteroidal objects recorded on September 20 by LINEAR, a tentative ephemeris was provided on the NEO Confirmation Page. This linkage was confirmed by observations obtained on Oct. 2 by J. G. Ries with the 0.76-m reflector at McDonald Observatory. Skiff adds that observations by L. H. Wasserman with the 1.1-m telescope at Lowell Observatory on Oct. 2 showed a 14" x 11" coma, elongated east-west. [IAUC 7501, 2000 October 2] The comet is periodic, with a period of 40 years and was at perihelion in mid July at a distance of 2.66 AU. It will fade.

    The IAU Committee on Small Bodies Nomenclature has agreed upon the names for the following five comets: C/2000 S3 (LONEOS); 150P/2000 WT_168 (LONEOS); C/2000 Y2 (Skiff); C/2001 G1 (LONEOS); C/2001 HT_50 (LINEAR-NEAT). [IAUC 7674, 2001 July 30]


    2000 S4 LINEAR-Spacewatch Tom Gehrels reported his discovery of a faint (20th mag) comet on October 2.15 images taken with the Spacewatch telescope at Kitt Peak, noting it to have a 4" tail in p.a. 170 deg. T. B. Spahr, Minor Planet Center, linked it to an asteroidal object observed on September 23 and 26 reported earlier by LINEAR and then found LINEAR observations made on September 1. At the request of Gehrels, P. Massey obtained images of the object in subarcsecond seeing with the 4-m Mayall Telescope at Kitt Peak on October 3.25 UT, showing the comet to have a fan-shaped structure 4" long spanning p.a. 0-80 deg. [IAUC 7502, 2000 October 3] The comet is close to perihelion at 2.3 AU and has a period of around 19 years.

    The IAU Committee on Small Bodies Nomenclature has given to comet P/2000 S4 (cf. IAUC 7502) the name LINEAR-Spacewatch. [IAUC 7553, 2000 December 31]


    2000 SV74 An apparently asteroidal 18th mag object reported by LINEAR on two nights in September (first observation on September 24.34), and published on MPS 19881 under the designation 2000 SV_74, has been found to be cometary (diffuse with 16" coma and 20" tail at p.a. 150 deg) by M. Tichy on CCD images taken on Oct. 19.8 UT with the 0.57-m f/5.2 reflector at Klet. [IAUC 7510, 2000 October 19] The comet will slowly fade from 13th magnitude. It was still around 13th magnitude in September 2002.

    82 observations received give an uncorrected preliminary light curve of m = 8.0 + 5 log d + 3.9 log r.

    Observations in ICQ format, Last observation 2002 September 12, updated 2002 October 1.


    2000 SO253 Anderson-LINEAR An apparently asteroidal 20th magnitude object discovered by LINEAR on September 24.35 (MPS 20197, 21370; discovery observation below) has been found to be cometary (highly condensed 5" coma and a 15" tail in p.a. 45 deg) on 300-s R-band CCD exposures taken on Nov. 24.3 UT by C. W. Hergenrother and A. E. Gleason with the Steward Observatory 1.54-m reflector. Additional observations and orbital elements (T = 2001 May 2.1 TT, q = 1.694 AU, i = 3.7 deg, P = 7.04 yr) are given on MPEC 2000-W39. [IAUC 7524, 2000 November 25]

    S. Nakano, Sumoto, Japan, reports his identification of comet P/2000 SO_253 (cf. IAUC 7524) with P/1963 W1 = 1963 IX (cf. IAUC 2013), which had been recorded on four Palomar Schmidt plates taken 1963 Nov. 22-25. The resulting orbital elements for the earlier apparition are T = 1963 Oct. 28.5 TT, q = 1.985 AU, i = 4.5 deg, P = 7.89 yr. The comet made approaches of 0.10 and 0.40 AU from Jupiter in 1961 Aug. and 1985 Apr., respectively. [IAUC 7548, 2000 December 23]


    2000 T2 P/Kushida-Muramatsu S. Nakano, Sumoto, Japan, reported the recovery by T. Oribe of comet P/1993 X1 (= 1993t = 1993 XIX) on CCD frames obtained with the 1.03-m reflector at Saji Observatory on Oct. 3.72 and 4. The images were clearly cometary with coma diameter 10". The indicated correction to the prediction by B. G. Marsden on MPC 31663 was Delta(T) = -0.04 day, but neither Nakano nor Marsden was able to obtain a link to the 1993-1995 data without dramatically systematic residuals, particularly in declination. Oribe later found faint images of the comet on frames obtained on Sept. 26. C. E. Delahodde, European Southern Observatory, independently recovered the comet (as a pointlike object measured by A. Maury) with the Danish 1.54-m reflector on Oct. 8. A further orbit computation by Marsden indicated that it was possible to link the 2000 data to the observations made after the 1994 conjunction. This computation revealed that single-night candidates for the comet found by C. W. Hergenrother, Lunar and Planetary Laboratory, with the 2.3-m Steward Observatory reflector at Kitt Peak in Sept. and Nov. 1999 indeed belong to the comet, which showed a possible 5" tail in p.a. 270 deg on the first occasion. Orbital elements satisfactorily linking the 49 observations during 1994 Dec. 8-1995 June 23 and 1999 Sept. 13-2000 Oct. 8 are given on MPEC 2000-T45, together with the 1999-2000 observations. [IAUC 7507, 2000 October 14]
    2000 U5 LINEAR A 17th mag object with unusual motion that was reported as asteroidal by the LINEAR survey on October 29.38 and posted on the NEO Confirmation Page has been found to be cometary by other observers. The object seemed diffuse with a 14" coma and 18" tail in p.a. 170 deg on CCD images obtained by J. Ticha and M. Tichy (Klet) on Oct. 30.0 UT. Images taken on Oct. 30.2 by D. A. Klinglesmith III (Socorro, NM) show slight diffuseness and a tail about 20" long in p.a. 220 deg; images by Y. Ikari (Moriyama, Japan) also show a tail in p.a. 220 deg on Oct. 30.6. J. Biggs (Perth Observatory) notes that images of C/2000 U5 were larger than nearby stars and elongated toward the south-southwest on Oct. 31.6. D. T. Durig (Sewanee, TN) found a tail about 25" long in p.a. 170 deg on Nov. 1.4 images. [IAUC 7515, 2000 November 1]
    2000 U6 P/Tichy An 18th mag object found by Milos Tichy on images taken at Klet with J. Ticha and M. Kocer on Oct. 23.08, originally reported as asteroidal, was subsequently noted to be diffuse on Klet images taken during Oct. 28.9-29.2 UT; Tichy also noted a 10" coma on Oct. 29.8 images. Images obtained on Nov. 1 by S. Sanchez and M. Blasco at Mallorca and by D. T. Durig at Sewanee also showed diffuseness. MPEC 2000-V03 contains the available astrometry and orbital elements (T = 2000 Oct. 4.6 TT, i = 19.3 deg, q = 2.150 AU, P = 7.3 yr). [IAUC 7515, 2000 November 1]
    A/2000 VU2 An interesting asteroid 2000 VU2 = 2000 VW55 was announced on MPEC 2000-W29. This has an 18.4 year period with a perihelion at 3.1 AU. The circular said: Reports of the stellar nature of 2000 VU2 have been received from T. B. Spahr on CCD images obtained on Nov. 20 UT with the 1.2-m Mount Hopkins reflector and C. W. Hergenrother on CCD images obtained on Nov. 23 and 24 with the 1.5-m Catalina reflector. [2000 November 24]
    2000 W1 Utsunomiya-Jones On November 19, S. Nakano, Sumoto, Japan, reported the visual discovery on November 18.82 by Syogo Utsunomiya (Aso, Kumamoto; 25x150 binoculars) of a possible 9th magnitude comet with coma diameter 5' moving rapidly southeastward in Vela. Attempts by several observers (including A. Hale, D. Seargent, J. Biggs, T. Urata, and J.Kobayashi) to confirm the object, at the request of Nakano and the Central Bureau, were unsuccessful. On November 25, A. C. Gilmore (Mount John University Observatory) reported the visual discovery of an apparent 8th magnitude comet by Albert F. Jones (Nelson, New Zealand, 0.078-m f/8 refractor, 30x) while observing the variable star T Aps at dawn on November 25.64; Jones reported the comet as being diffuse with coma diameter about 4' in morning twilight. The possibility that Jones' object might be the same as that reported by Utsunomiya was explored by the Central Bureau, and a search ephemeris from plausible parabolic orbital elements fitted to the November 18 and 25 approximate positions was circulated to numerous southern-hemisphere observers. Confirming CCD astrometry was made by Gilmore with the 1.0-m f/7.7 reflector at Mt. John. [IAUC 7526, 2000 November 28] This is Albert Jones' second comet discovery; the first was discovered in 1946! The comet has a perihelion distance of 0.3 AU, but is intrinsically faint and may not survive perihelion passage. It is currently a southern hemisphere object. The comet transited the SOHO LASCO C3 field at the end of December and early January.

    This is how the comet was discovered:
    On November 18 UT Japanese comet hunter Syogo Utsumoniya saw a possible comet in Vela, very low in his southern sky. Utsunomiya watched the eighth magnitude comet through his 25 x 150 mm binoculars for 40 minutes as dawn approached. During that time the comet moved southeastward about 10 minutes of arc, one third of a full-moon's diameter. Utsunomiya passed the information onto the International Astronomical Union's Central Bureau. They asked a few southern hemisphere observers (none in NZ!) to confirm the discovery. They were unable to locate the comet.

    A week later, on Sunday morning Nov. 26 NZ date, Albert Jones of Nelson found the sky had cleared. He got out his 78 mm refractor with the 30x eyepiece and aimed it at the variable star T Apodis. He had intended to observe T Aps two mornings earlier but "ran out of dark sky" before he got to it. Just 50' northwest of the variable Albert saw a hazy spot which he instantly recognised as a comet. He made position and magnitude estimates as dawn came up and phoned them to the University of Canterbury's Mt John Observatory. We immediately emailed Albert's discovery position to the IAU Bureau.

    At the Bureau Brian Marsden and Dan Green surmised that the two fast-moving eighth magnitude comets were one and the same object. Brian fitted a parabolic orbit to the two positions and emailed search ephemerides to a few southern hemisphere observers. (The Bureau is very cagey about a suspected comet lest an unscrupulous person 'discovers' it.)

    As luck would have it, Mt John had a CCD camera on its 1m telescope. Glen Bayne was taking direct images of Magellanic Cloud eclipsing binary stars as part of his PhD project. (The same CCD is in frequent use on the 1m but attached to a large spectrograph, not available for direct picture taking.) Glen was happy to get pictures of the comet in the twilight.

    Using a 15 cm finder 'scope on one of Mt John's other telescopes, Alan Gilmore located the comet in the twilight. This allowed quick setting of the 1m onto the comet and CCD images to be taken. Alan measured these and sent the results off to the IAU Bureau. Three hours later another set of CCD images were obtained by Glen and Alan and the futher positions sent off.

    Brian Marsden was then able to fit a semi-accurate orbit to the three nights' observations and show conclusively that the comets seen by Utsunomiya and Jones were indeed the same object. IAU Circular 7526 appeared a few hours later, announcing the discovery and designating the comet 2000 W1. Numerous CCD measurements over the next four days allowed a more accurate orbit to be calculated. This appeared in Minor Planet Electronic Circular 2000-W62 on Nov. 30.

    At 80 years old, Albert Jones is the oldest person ever to discover a comet. The next nearest was Lewis Swift who was 79 when he found his last comet in 1899. Albert also holds the record for the longest interval between comet discoveries. His previous comet, also found in a variable star field, was 1946 P1 found in October 1946.

    At discovery Comet Utsunomiya-Jones was about 50 million km from earth, hence its rapid movement across the sky. Perspective slows the apparent movement as the comet moves directly away from us and on toward the sun. The angle between the comet and the sun will shrink, causing the comet to sink into the south-west evening twilight. Counterbalancing this, to a greater or lesser degree, is the comet's expected increase in brightness as it nears the sun. So nobody can predict how long the comet will remain visible. It is likely to have disappeared by December 22 when it will be just 19 degrees from the sun.

    Comet Utsunomiya-Jones passes closest to the sun on December 26.6 UT. It will remain hidden in the sun's glare till mid January when it will start climbing up the dawn sky. If it behaves like a 'normal' comet then it should have a total magnitude (m1) around nine, visible in medium-sized telescopes.
    -- Alan Gilmore & Pam Kilmartin

    Albert described his discovery thus:
    On the morning of November 26, I was up early (as I do on clear mornings) observing variable stars before dawn, then as I was pointing the telescope to view a faint variable star south of the Southern Cross and Pointers, I noticed a fuzzy object that was new to the region and recognising that it was a comet and not permanent celestial scenery like a nebula, star cluster or galaxy, I noted its position and other details. Then I phoned Alan Gilmore at the Mount John University Observatory (by Lake Tekapo) and told him about it and asked he if he knew about it and its name, but he had no information about it so he e-mailed a message to the International Central Bureau for Astronomical Telegrams (CBAT) at Cambridge, Mass. USA. At breakfast that morning Carolyn wondered why I did not get back to bed before bright daylight - I replied that I had been on the phone to Alan about a comet asking about whether it was a known one. After breakfast a message came from the CBAT saying that it might be the same object that a Japanese comet hunter had seen a week beforehand but which had not been seen again because it was moving south so fast and was thus unconfirmed Using the Japanese positions for the comet and mine, they determined that it was the same object to be known as Comet 2000 W1 Utsunomiya-Jones It has quickly moved towards the west and is moving north again. December 5 was the last evening that I saw it, as it was too low in the sky and behind trees the next night. Next January when the comet's motion brings it into the eastern sky before dawn, it will be much fainter as it races away to the outer reaches of the Solar System. Over 50 years ago, I spent some time looking for unknown comets, and now I find one while pointing the telescope to a variable star ! The moral of the story is to keep looking and you never know what you might see. You just need to be lucky enough to look at the right place at the right time ! By the way, I am told that I am the oldest person to have discovered a comet.

    C. W. Hergenrother, Lunar and Planetary Laboratory, reports that this comet has undergone a rapid fading, with R-band photometry showing m_1 about 16.5 for a 1'.7 coma on a co-added 2400-s CCD exposure taken on Feb. 12.6 UT with the Catalina 1.5-m reflector. No nuclear condensation was visible to a limiting mag of 21.0. Earlier visual m_1 estimates: Jan. 17.86, 10.1 (Y. Nagai, Yamanashi, Japan, 0.32-m reflector); 22.88, 10.5 (K. Yoshimoto, Yamaguchi, Japan, 0.25-m reflector); 28.77, 12.0: (M. Mattiazzo, Wallaroo, S. Australia, 0.20-m reflector); 30.28, 11.6 (P. M. Raymundo, northwest of Salvador, Brazil, 0.25-m reflector). [IAUC 7586, 2001 February 22]

    Further to the report on IAUC 7586, A. C. Gilmore reports that 3-min unfiltered CCD images taken on Mar. 3.61 UT with the University of Canterbury's Mount John Observatory 1-m f/7.7 telescope showed only a diffuse parabolic glow at the comet's expected position. The glow was brighter and about 1' across at the 'head' end. The 'tail', in p.a. 80 deg, was at least 10' long and widened to about 2' across at the frame's edge. No stellar central condensation was found, though anything brighter than red mag 20 should have been detected. [IAUC 7594, 2001 March 6]

    Michael Mattiazzo observed it with 7x50B on November 28.52, estimating it at 7.0, DC4, diameter 5'. It displayed a faint ion tail in 25x100B. I was in the Southern Ocean on board the RRS Ernest Shackleton and made several attempts at observing the comet. These were generally foiled by bright skies or cloud, but I successfully glimpsed it in 10x50B on December 6.09 when it was 6.3 and again the following night.

    32 observations received give an uncorrected preliminary light curve of m = 10.8 + 5 log d + 12.7 log r.

    Observations in ICQ format, last observation 2001 January 28, updated 2001 May 2.


    2000 WM1 LINEAR An apparently asteroidal 18th mag object with unusual motion reported by the LINEAR team on Dec. 16.07 was posted on the NEO Confirmation Page. Subsequent astrometry permitted a linkage to another set of observations by LINEAR on Nov. 16.14 and 18, designated 2000 WM_1 on MPS 22800. An observation of 2000 WM_1 by T. B. Spahr (Smithsonian Astrophysical Observatory 1.2-m reflector at Mt. Hopkins) on Dec. 20.148 UT shows the object to have a 10" coma and a broad, faint tail some 10"-20" long in p.a. 45 deg: [IAUC 7546, 2000 December 20]

    Brian Marsden notes on MPEC 2001-U43 [2001 October 23], which gives the latest orbit for the comet, that 'The "original" and "future" barycentric values of 1/a are +0.000500 and -0.000266 (+/- 0.000002) AU**-1, respectively.' The original value is greater than 10E-04, hence the comet is probably not a new arrival from the Oort cloud and has made at least one previous visit to the inner solar system.

    Schleicher adds that his narrowband photometry of comet C/2000 WM_1, obtained as above on Sept. 18 and 19 (at r = 2.33), yields the following averaged results: log Q(OH) = 27.87; equivalent log Q(water; vectorial) = 27.87; log Af(rho) = 2.42. No temporal or aperture variations were observed. [IAUC 7722, 2001 September 21]

    J. Watanabe, National Astronomical Observatory (NAO) of Japan, reports the following antitail lengths and position angles for this comet from I-band CCD images taken by H Fukushima with the NAO 0.50-m f/12 reflector (noting the earth's passage through the orbital plane of the comet on Nov. 20.18 UT): Nov. 16.503, > 8'.5, 283 deg; 17.542, > 6'.5, 300 deg; 18.526, > 7'.9, 302 deg; 19.555, > 6'.2, 317 deg; 22.372, > 4'.7, 1 deg. Small scale jet-like structure near the nucleus was also recognized on these images. [IAUC 7762, 2001 November 29]

    Further selected total-visual-magnitude and coma-diameter estimates: Nov. 14.27 UT, 7.2, 12' (C. S. Morris, Fillmore, CA, 10x50 binoculars; 1.1-degree tail); 19.95, 6.3, 18' (R. Haver, Frasso Sabino, Italy, 10x50 binoculars); 22.91, 5.8, 20' (B. H. Granslo, Fjellhamar, Norway, 7x50 binoculars); 30.78, 5.7, 15' (J. J. Gonzalez, Asturias, Spain, 7x50 binoculars); Dec. 3.38, 5.4, 21' (Y. Nagai, Yamanashi, Japan, 7x35 binoculars); 3.79, 5.3, - (Gonzalez). [IAUC 7766, 2001 December 5]

    The comet will be visible until August 2002.

    I observed it on October 9 under relatively poor conditions, using the Northumberland refractor x230. The comet was surprisingly easy to see and I estimated it at around 12th magnitude. An observation with the Thorrowgood refractor on October 23 put the comet at 10.3, generally diffuse but with a small star-like condensation.

    By the end of November 2001 the comet had reached 5th magnitude and was an easy object. It then slowly faded and observations by Southern Hemisphere observers in mid January put the comet at 6th magnitude, about a magnitude fainter than suggested by the preliminary light curve.

    Andrew Pearce reports an outburst as follows: 2002 Jan 27.85UT: m1=4.6, Dia=3.5', DC=8...20x80B...Andrew Pearce (Nedlands, Western Australia)[Comet has clearly undergone a significant brightness increase in the last 24 hours or so. Surface brightness of the coma has increased significantly. Faintly visible to the naked eye even at only 10 deg altitude. Tail visible 0.5 deg long in PA 195 deg. Estimate made in 8x40B at the same time: m1=4.6, Dia=4', DC=8. I suspected something may be up the previous morning but the observation was hampered with the comet only 1' away from a 6th mag star. Quick examination of the comet through a 20cm reflector (90x) revealed an intense central condensation which appeared distinctly non stellar. No evidence of any split, however the telescope probably lacked the degree of resolution required to confirm this.]

    752 visual observations received give an uncorrected preliminary light curve of m = 7.1 + 5 log d + 10.6 log r which does not take into account the outburst, though the comet is currently close to the indicated magnitude.

    Observations in ICQ format, last observation 2002 August 8, updated 2002 October 1.


    A/2000 WO107 This unusual asteroid, discovered by LINEAR on November 29.39 at 16th magnitude has a perihelion distance of 0.20 AU and a period of 0.87 years. It was last at perihelion in August. [MPEC01-V58]
    2000 WT168 150P/LONEOS After the publication (MPS 23043) of the initial observations of the apparently asteroidal 17th mag object 2000 WT_168 by LONEOS on November 25.44 and LINEAR on November 27.37, linkage to further observations (including prediscovery data) showed the orbit to be cometary, although observations did not show cometary activity in December (cf. MPEC 2000-Y21). CCD exposures taken with the 1.5-m reflector at Catalina on 2001 Feb. 13.3 UT by C. W. Hergenrother, however, do show the object to be cometary (highly condensed 9".7 coma with red mag 16.3 and 8".0 tail in p.a. 110 deg). Confirmation of cometary activity has been obtained in CCD observations by J. Ticha and M. Tichy at Klet on Feb. 16.9 (0.57-m reflector; 9" tail in p.a. 155 deg and faint asymmetric coma) and by M. Hicks and B. Buratti at Palomar on Feb. 17.2 (1.5-m reflector; faint teardrop-shaped tail about 15" long in p.a. 60 deg). The comet has a 7.7 year period, with perihelion at 1.76 AU on 2001 March 23. [IAUC 7584, 2001 February 17] It is not clear what, if any, name the comet will receive, though it has now been numbered.

    R. M. Stoss, Starkenburg-Sternwarte, Heppenheim; and R. H. McNaught, Siding Spring Observatory, report the identification with P/2000 WT_168 of two asteroidal trails appearing on U.K. Schmidt plates taken by M. R. S. Hawkins and P. R. Standen on 1978 Mar. 6 and 1986 Mar. 14. Astrometric measurements by McNaught, M. Read, and Stoss appear on MPEC 2001-F17, together with orbital elements by B. G. Marsden from 190 observations spanning 1978-2001 (T = 1978 Jan. 21, 1985 Oct. 22, 1993 July 18, and 2001 Mar. 23). [IAUC 7600, 2001 March 20]

    The IAU Committee on Small Bodies Nomenclature has agreed upon the names for the following five comets: C/2000 S3 (LONEOS); 150P/2000 WT_168 (LONEOS); C/2000 Y2 (Skiff); C/2001 G1 (LONEOS); C/2001 HT_50 (LINEAR-NEAT). [IAUC 7674, 2001 July 30]

    Observations in ICQ format, last observation 2001 February 17, updated 2002 April 2.


    2000 Y1 Tubbiolo R. S. McMillan, Lunar and Planetary Laboratory, reports the discovery by Andrew F. Tubbiolo of a faint 19th mag comet with the 0.9-m Spacewatch telescope at Kitt Peak on December 16.18. The object showed a 20"-30" tail on December 16 and 17. Parabolic orbital elements (T = 2001 February 6, i = 138 deg, q = 7.97 AU) are given on MPEC 2000-Y06. [IAUC 7544, 2000 December 18]
    2000 Y2 Skiff B. Skiff, Lowell Observatory, reports the discovery of a 17th magnitude comet by the LONEOS program on December 27.34. Confirming CCD images by L. Wasserman (1.07-m Lowell Observatory telescope) show a coma diameter of about 9" and a tail about 14" long toward the southwest. [IAUC 7549, 2000 December 27] The comet is in a distant parabolic orbit and will not get much brighter.

    The IAU Committee on Small Bodies Nomenclature has agreed upon the names for the following five comets: C/2000 S3 (LONEOS); 150P/2000 WT_168 (LONEOS); C/2000 Y2 (Skiff); C/2001 G1 (LONEOS); C/2001 HT_50 (LINEAR-NEAT). [IAUC 7674, 2001 July 30]


    2000 Y3 Scotti J. V. Scotti, Lunary and Planetary Laboratory, reports his discovery of a 19th magnitude comet with the 0.9-m Spacewatch telescope on December 30.16. The comet shows a coma diameter of 7" and a 0'.93 tail in p.a. 269 deg; he also measures m_2 = 19.7. [IAUC 7552, 2000 December 30]

    Additional astrometry, including prediscovery observations by LINEAR on Nov. 29 and Dec. 21 identified by B. G. Marsden, appear on MPEC 2000-Y47, together with the following orbital elements showing this to be a short-period comet. The elements indicate an approach to within 0.05 AU of Jupiter in Sept. 1998. Further to IAUC 7552, J. V. Scotti notes that the comet showed a 7" coma and a 1'.16 tail in p.a. 270 deg on a Spacewatch CCD image taken on Dec. 31.174 UT. An image obtained at Klet on Dec. 30.79 shows a coma diameter of 8" and m_1 = 17.5. [IAUC 7553, 2000 December 31] The comet will fade.


    2000 Y6 SOHO 2000 Y7 SOHO Further to IAUC 7565, D. Hammer reports his measurements for two comets (initial observations given below) that appear to be two components of an earlier single comet. C/2000 Y6 and C/2000 Y7 were found by M. Meyer and by S. Hoenig, respectively, in C2 coronagraph data on SOHO website images. D. Biesecker provides V magnitudes for C/2000 Y6: Dec. 20.463 UT, 7.8; 20.504, 7.8; 20.580, 7.5; 20.588, 7.6; 20.604, 8.0; 20.646, 8.3. The reduced observations and parabolic orbital elements (T = 2000 Dec. 20.85 TT, q = 0.025 AU, Peri. = 88-89 deg, Node = 229 deg, i = 87-89 deg) by B. G. Marsden, together with a search ephemeris for groundbased observers, are given on MPEC 2001-B08.
       Comet         2000 UT           R.A. (2000) Decl.
       C/2000 Y6     Dec. 20.454      17 48.7      -23 20
       C/2000 Y7          20.463      17 48.8      -23 19
    

    2000 Y10 P/Mueller 4 S. Nakano, Sumoto, Japan, reports the recovery of P/1992 G3 (= 1992g = 1992 IV) by T. Oribe (Saji Observatory) on CCD images taken with a 1.03-m reflector. The comet is faint and of stellar appearance on 2000 Dec. 22.85 (m_2 = 20.5). The indicated correction to the orbital elements on MPC 31663 (ephemeris on MPC 41213) is Delta(T) = +0.23 day. [IAUC 7577, 2001 February 1]
    2000 YN30 (212P/NEAT) This unusual asteroid has a perihelion distance of 1.65 AU and a period of 7.8 years. It is at perihelion in early December 2008. [MPEC 2008-V41, 2008 November 7] It can pass within 0.4 AU of Jupiter.

    Observations in early January 2009 showed a coma, and so with observations over two returns and a secure orbit it was numbered 212.


    Ephemerides of current comets are available on the CBAT ephemeris page and positions of newly discovered comets are on the NEO confirmation page.
    More information on LINEAR. List of comets discovered by selected search programs.
    The Northumberland refractor is the telescope that was used in the search for Neptune. It now has a 0.30-m f20 doublet lens which gives a stellar limiting magnitude of around 15 at the zenith on good nights. The Thorrowgood refractor was built in 1864 and has a 0.20-m f14 doublet lens.
    Published by Jonathan Shanklin. Jon Shanklin - jds@ast.cam.ac.uk