BAA Comet Section : Periodic Comets 300 - 399

Updated 2014 July 14


  • 300P/Catalina
  • 301P/LINEAR-NEAT
  • 302P/Lemmon-PanSTARRS
  • 303P/NEAT
  • 304P/Ory
  • 305P/Skiff
  • P/LINEAR
  • 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]


    P/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]


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