BAA Comet Section : Periodic Comets 300 - 399

Updated 2014 October 25


  • 300P/Catalina
  • 301P/LINEAR-NEAT
  • 302P/Lemmon-PanSTARRS
  • 303P/NEAT
  • 304P/Ory
  • 305P/Skiff
  • 306P/LINEAR
  • 307P/LINEAR
  • 308P/Lagerqvist-Carsenty
  • 309P/LINEAR
  • 310P/Hill
  • 311P/PanSTARRS
  • 312P/NEAT
  • P/Gibbs
  • P/Montani
  • Comets 1 - 99
  • Comets 100 - 199
  • Comets 200 - 299
  • Comets 300 - 399
  • Not yet numbered objects
  • 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.


    300P/Catalina = 2005 JQ5 = 2014 G2
    An apparently asteroidal object of 17th magnitude found by the Catalina Sky Survey on 2005 May 6.28 has been found to show cometary features. It reached perihelion at 0.83 au in late July 2005 and has a period of 4.4 years. The comet reached magnitude 10.5.

    The comet was recovered by M. Masek, J. Cerny, J. Ebr, M. Prouza, P. Kubanek, M. Jelinek, K. Honkova and J. Jurysek at the Pierre Auger Observatory, Malarque with the 0.3m reflector on April 9.39. [MPEC 2014-G70, 2014 April 10]. The comet returns to perihelion 0.1 days earlier than predicted.

    The comet can make close approaches to Venus, Earth and Mars. Its last close approach to Earth was at the discovery apparition in 2005, when it came to 0.10 au and in 2036 it will approach to 0.06 au. It will approach within 0.08 au of Mars in 2132 and approached Venus to 0.09 au in 1957.


    301P/LINEAR-NEAT = 2001 BB50 = 2014 K1
    S. Pravdo, K. Lawrence, and E. Helin, Jet Propulsion Laboratory, reported the discovery of an 18th mag comet on 2001 March 20 CCD images taken with the NEAT 1.2-m reflector at Haleakala, the object showing a short eastward tail, a nuclear condensation of size < 3", and a coma diameter of about 10". T. B. Spahr, Minor Planet Center, linked this object first with an object reported as asteroidal by LINEAR on March 18 (m_2 = 19.5) and then to the LINEAR object 2001 BB_50, observed on January 21 and 26 (MPS 25734). Following posting on the NEO Confirmation Page, C. Jacques, Belo Horizonte, Brazil, also reported a 10" coma and m_1 = 18.6 on CCD images taken on March 21 (0.3-m reflector). Full astrometry and the orbital elements appear on MPEC 2001-F26. [IAUC 7601, 2001 March 21] The comet has a perihelion distance of 2.35 au and is intrinsically faint. Its period is 13.6 years.

    2001 BB50 (P/LINEAR-NEAT) was recovered in images from PanSTARRS taken on 2014 May 17.28, with earlier images taken at the SATINO remote observatory, Haute Province on 2014 March 1.93. The comet will return to perihelion 1.76 days earlier than predicted and has a period of 13.7 years.


    302P/Lemmon-PanSTARRS = 2007 RJ236 = 2014 K2
    A 21st magnitude comet discovered in PanSTARRS 1 images taken with the 1.8m Ritchey-Chretien on April 29.36, was linked to asteroid 2007 RJ236 discovered during the Mt Lemmon survey on 2007 September 13.30. It was also linked to observations made by the Purple Mountain Observatory in 2007 August. [MPEC 2014-K28, 2014 May 23] The comet is at perihelion at 3.3 au in 2016 April and has a period of 8.86 years.
    303P/NEAT = 2003 U3 = 2014 L1
    NEAT discovered an 19th mag comet on 2003 October 22.29. It was past perihelion at 2.5 au in late April and had a period around 11.5 years.

    K. Lawrence, Jet Propulsion Laboratory, reports the discovery by the NEAT project of a 19th magnitude comet on 2003 October 22.29. Observations by J. Young at Table Mountain on October 23.2 UT show a 3" coma with a short, broad, fan-shaped tail about 8" long spanning p.a. 255-285 deg. [IAUC 8230, 2003 October 23]

    2003 U3 (P/NEAT) was recovered in images taken at the ESA Optical Ground Station in Tenerife with the 1.0m reflector by P Ruiz. The comet will return to perihelion 1.80 days earlier than predicted and has a period of 11.4 years.    [MPEC 2014-L12, 2014 June 2]


    304P/Ory = 2008 Q2 = 2014 L4
    An 18th magnitude apparently asteroidal object discovered by Michel Ory of Delemont, Switzerland, on CCD images obtained with a 0.61-m f/3.9 reflector at Vicques was found to show cometary characteristics after posting on the NEOCP. The comet has a period of 5.8 years with perihelion at 1.4 au. It was at a perihelic opposition.

    Michel Ory is a Swiss amateur astronomer and president of the Société jurassienne d'astronomie, which has a well equipped observatory in the foothills of the Jura.

    The comet passed 0.3 au from Jupiter in November 2005, before which the perihelion distance was a little larger.

    2008 Q2 was recovered by Hidetaka Sato in images taken with the iTelescope 0.51m astrograph at Siding Spring on 2014 June 2.79. The comet is very close to the prediction by B. G. Marsden on MPC 65935. It has a period of 5.8 years.  [MPEC 2014-M10, CBET 3906, 2014 June 18]


    305P/Skiff = 2004 V1 = 2014 N1
    Brian Skiff discovered an 18th magnitude comet on LONEOS images taken with the 0.59-m Schmidt on November 4.08. Prediscovery LINEAR images showed that it ws approaching perihelion at 1.42 au in early December and had a period of 10.0 years.

    B. Skiff, Lowell Observatory, reports his discovery of a comet on LONEOS images obtained on Nov. 4.1 UT with the 0.59-m Schmidt telescope, the object showing a moderately condensed coma of diameter 25" and a weak tail 50" long in p.a. 75 deg. Following posting on the "NEO Confirmation Page", B. L. Stevens (Las Cruces, NM, 0.3-m Schmidt-Cassegrain telescope) reports that his CCD images taken on Nov. 4.2 show a 30" tail in p.a. 55 deg. [IAUC 8426, 2004 November 4]

    Gareth Williams found images of 2004 V1 (P/Skiff) in images taken taken with the PanSTARRS 1 1.8m Ritchey-Chretien on July 3.51. The comet will return to perihelion 0.32 days earlier than predicted and has a period of 9.9 years.  [CBET 3918, MPEC 2014-N43, 2014 July 7]


    306P/LINEAR = 2003 O3 = 2014 M5
    A 19th magnitude comet was discovered by LINEAR on 2003 July 30.39, although other CCD observers estimated it at 18th magnitude. It was confirmed as cometary by Peter Birtwhistle amongst others. The comet reached perihelion at 1.25 au in mid August. It passed 0.3 au from Jupiter in 1979 November and the period is 5.5 years.

    An apparently asteroidal object reported by LINEAR, and posted on the NEO Confirmation Page, was found to be apparently cometary on CCD images taken by P. Birtwhistle (Great Shefford, U.K., 0.30-m reflector; very faint tail about 10" long in p.a. approximately 270-280 deg on July 31.10 and Aug. 2.08 UT; mag 18.1 and coma diameter about 5" on Aug. 2.08), by J. Ticha and M. Tichy (Klet, 1.06-m KLENOT telescope; diffuse with a wide tail in p.a. 260 deg on Aug. 3.01), and by J. McGaha (near Tucson, AZ; possible tail spike 5" long in p.a. 300 deg on Aug. 3.38 with a 0.30-m reflector; possible fan-shaped tail 5" long in p.a. 260 deg on Aug. 5.33 with a 0.62-m reflector). The preliminary orbital elements indicate that the comet passed 0.3 au from Jupiter in Nov. 1979. [IAUC 8174, 2003 August 5]

    2003 O3 (P/LINEAR) was recovered by Hidetaka Sato in images taken with the iTelescope 0.51m astrograph at Siding Spring on June 21.77. The comet was missed at its 2009 return and is close to the prediction in the 2014 ICQ Handbook. It has a period of 5.5 years with perihelion at 1.3 au.  [MPEC 2014-N76, CBET 3922, 2014 July 14]


    307P/LINEAR = 2000 QJ46 = 2014 O1
    A 19th magnitude asteroid found by LINEAR on 2000 August 24.27 was found in 2005 October 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.

    A team of observers at the European Space Agency's Optical Ground Station recovered 2000 QJ46 (P/LINEAR) with the 1.0m reflector on 2014 July 25.15. The indicated correction to the prediction by B. G. Marsden on MPC 75735 is Delta(T) = -0.24 day.  [CBET 3923, MPEC 2014-O44, 2014 July 27] The comet has a period of 14 years and reaches perihelion at 1.9 au in December.


    308P/Lagerqvist-Carsenty = 1997 T3 = 2014 O2
    Uri Carsenty and Andreas Nathues, of the DLR Institute of Planetary Exploration, Berlin discovered a 19th mag cometary object on 1997 October 5.1 during the course of the Uppsala-DLR Trojan Survey, in collaboration with C-I Lagerkvist, S Mottola and G Hahn. [IAUC 6754, 1997 October 7]. It is in a distant elliptical orbit with a period of 19.7 years. The comet was not named until January 1998, when it was named after the discoverer and person who found that it was a cometary object [IAUC 6811, 1998 January 23]

    A team of observers at the European Space Agency's Optical Ground Station recovered 1997 T3 (P/Lagerqvist-Carsenty) with the 1.0m reflector on 2014 July 29.08. The indicated correction to the prediction by B. G. Marsden on MPC 79348 is Delta(T) = -1.28 days. [CBET 3925, MPEC 2014-O65, 2014 July 30] The comet has a period of 17 years and reaches perihelion at 4.2 au in 2015 May.


    309P/LINEAR = 2005 Q4 = 2014 Q4
    A 19th magnitude, asteroidal object discovered by LINEAR on August 31.40 and posted on the NEOCP was shown to have a tail by J Lacruz (Madrid) and J Young (Table Mountain, USA). The comet reaches perihelion at 1.75 AU at the end of September. It is in an eliptical orbit with a period of 9.4 years.

    Krisztian Sarneczky recovered 2005 Q4 (P/LINEAR) with a 0.6m Schmidt on 2014 August 23.00, with PanSTARRS images from the same night later found by Gareth Williams. The indicated correction to the prediction by Gareth Williams on MPC 75706 is Delta(T) = -0.26 day.  [CBET 3937, MPEC 2014-Q39, 2014 August 24] The comet has a period of 9.4 years and reaches perihelion at 1.7 au in 2015 February.


    310P/Hill = 2006 S6 = 2014 Q5
    This was the second of two comet discoveries by Rik Hill on the same night, 2006 September 28. It was of 18th magnitude. and found on September 28.40. It was at perihelion at 2.4 au in mid 2006 October.

    Krisztian Sarneczky recovered 2006 S6 (P/Hill) with a 0.6m Schmidt at the Piszkesteto Station of Konkoly Observatory on 2014 August 24.98. The indicated correction to the prediction by Gareth Williams on MPC 79348 is Delta(T) = -0.32 day.  [CBET 3938, MPEC 2014-Q53, 2014 August 26] The comet has a period of 8.5 years and reaches perihelion at 2.4 au in 2015 April.


    311P/PanSTARRS = 2013 P5
    Pan-STARRS discovered a 21st magnitude comet on 2013 August 15.50.  [MPEC 2013-Q37, 2013 August 27]  It reached perihelion at 1.9 au in 2014 April and has a low eccentricity and a very short period of around 3.2 years.  There are some similarities between its orbit and that of Flora group asteroids and it is probably another example of a Main Belt Comet. The HST took images of it on September 10 and 23, showing a complex tail structure that might be linked to rotation rate.  It was numbered in 2014 once observations extended over a complete orbit.
    312P/NEAT = 2001 Q11 = 2014 R2
    In March 2010 Maik Meyer, Limburg, Germany, discovered a 19th magnitude comet on images obtained by the NEAT project on three nights at Palomar and on five nights at Haleakala during August - December 2001. The August 18.47 Palomar discovery-night images show a 21" tail in p.a. 256 deg, and there was a 0'.2 tail in p.a. 264 deg on the August 22 Haleakala frames. The August 18 observations were reported (though not as being cometary) by NEAT at the time (mag 18.6-18.7), but the object was never followed up; likewise for four LONEOS observations (mag 17.9) on October 24. The comet was at perihelion in 2001 June and has a period of around 6.2 years. Searches of relevant frames by Meyer and others have so far failed to show the comet at its return in 2007. [IAUC 9129, 2010 March 19]

    2001 Q11 (P/NEAT) was recovered in images taken by Eric Christensen at Mt Lemmon with the 1.5m reflector on September 6.45.  After the object was posted on the PCCP, Hidetaka Sato was able to find the comet in images taken on July 28.82.  The comet will return to perihelion 0.68 days earlier than predicted and has a period of 6.4 years.  It was discovered by Maik Meyer in 2010 in images taken in 2001, though no images could be found from the 2007 return. [CBET 3971, MPEC 2014-R91, 2014 September 12]


    P/Gibbs = 2003 S10 = 2014 S4
    Alex Gibbs discovered a 19th magnitude comet on September 24.31 on images taken during the Catalina Sky Survey with the 0.68m Schmidt. Subsequently pre-discovery images were found in Sky Survey data. [CBET 3991, MPEC 2014-S115, 2014 September 27]. 

    With an improved orbit, it was linked to an object found in LONEOS images from September and November 2003 and was designated 2003 S10 for that return. [MPEC 2014-U24, 2014 October 20]

    The comet was at perihelion at 2.4 au in 2014 August and has a period of 5.6 years.


    P/Montani = 1997 G1 = 2014 U1
    1997 G1 P/Montani was announced on IAUC 6622. It was a 19th mag object discovered by Joe Montani of the Spacewatch team. It is a distant object, with a perihelion distance of 4.3 AU and a period of around 20 years.

    1997 G1 (P/Montani) was recovered on October 13.31 at the Steward Observatory, Kitt Peak by Terry Bressi and A F Tubbiolo with the 0.9m reflector.


    Published by Jonathan Shanklin. Jon Shanklin - jds@ast.cam.ac.uk