BAA Comet Section : Comets discovered in 2019

Updated 2019 January 18


  • 2019 A1 (P/PanSTARRS)
  • 2019 A2 (P/ATLAS)
  • 2019 A3 (P/PanSTARRS)
  • 2019 A4 (P/PanSTARRS)
  • 2019 A5 (PanSTARRS)
  • 2019 A6 (P/Lemmon-PanSTARRS)
  • A/2019 AB4 [A/PanSTARRS]

  • 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 comets made in 2019 are given in ICQ format. 

    Full details of recently discovered objects will not appear until they are available on the CBAT web pages. The actual accuracy of preliminary orbits is often (nearly always) much worse than the published accuracy implies.  In part this is because each orbital solution is treated as a mathematical construct and does not take account of observational error.  JPL does publish the errors, whereas the MPECs do not.


    2019 A1 (P/PanSTARRS)
    A 21st magnitude comet was discovered in PanSTARRS 1 images taken with the 1.8m Ritchey-Chretien on January 3.63.  There were prediscovery observations from Mt Lemmon on December 4 and PanSTARRS on December 20. It was placed on the PCCP as P10KX4b.  [CBET 4591, MPEC 2019-A101, 2017 January 7]  The comet has a period of around 12 years and was at perihelion at 2.2 au in 2018 October. Remarkably PanSTARRS has discovered the first comet of the year for five years running. 
    2019 A2 (ATLAS)
    A 19th magnitude comet was discovered in images taken with the 0.5m Schmidt at Haleakala on January by the ATLAS (Asteroid Terrestrial-impact Last Alert System) team. There were pre-discovery images made in December from Purple Mountain Obervatory, ATLAS and Oukaimeden Observatory. It had been posted on the PCCP as A10b3Tk. [CBET 4595, MPEC 2019-A26, 2019 January 8]. The comet was at perihelion at 3.6 au in 2018 December and has a period of around 13 years.
    2019 A3 (P/PanSTARRS)
    A 22nd magnitude comet was discovered in PanSTARRS 1 images taken with the 1.8m Ritchey-Chretien on January 3.27.  There were prediscovery observations from PanSTARRS 1 on August 8, 11 and 21 and PanSTARRS 2 on October 10, 18 and November 13. It was placed on the PCCP as P10KTLx.  [CBET 4598, MPEC 2019-A166, 2017 January 10]  The comet has a period of around 5.6 years and was at perihelion at 2.3 au in 2018 August.
    2019 A4 (P/PanSTARRS)
    A 21st magnitude comet was discovered in PanSTARRS 1 images taken with the 1.8m Ritchey-Chretien on January 10.37.  There were prediscovery observations from PanSTARRS 1 on January 3. It was placed on the PCCP as P10Lm7w.  [CBET 4600, MPEC 2019-B44, 2017 January 17]  The comet has a relatively short period of around 4.2 years and was at perihelion at 2.4 au in 2018 November.
    2019 A5 (PanSTARRS)
    A 21st magnitude comet was discovered in PanSTARRS 1 images taken with the 1.8m Ritchey-Chretien on January 13.49.  There were prediscovery observations from PanSTARRS 1 on January 4. It was placed on the PCCP as P10LuEh.  [CBET 4601, MPEC 2019-B45, 2017 January 17]  The comet was at perihelion at 4.5 au in 2017 October.
    2019 A6 (P/Lemmon-PanSTARRS)
    A 21st magnitude comet was discovered in PanSTARRS 1 images taken with the 1.8m Ritchey-Chretien on January 7.51.  It was placed on the PCCP as P10L7nx. Following confirmation, Gareth Williams identified it with an undesignated possible NEA reported by Mt Lemmon on December 19, with additional images on December 14 and 16.  [CBET 4602, MPEC 2019-B46, 2017 January 17]  The comet has a period of around 12 years and was at perihelion at 1.9 au in 2018 August.
    A/2019 AB4 [PanSTARRS]
    PanSTARRS discovered an asteroid in images taken with the 1.8m Ritchey-Chretien on January 3.2. The object, classified as a Main-belt Asteroid, is at perihelion at 2.0 au in 2019 March and has a period of around 3.5 years. It was briefly placed on the PCCP as P10KTPv. No cometary activity has been confirmed.
    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. A 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