BAA Comet Section : Comets discovered in 2019

Updated 2019 June 3


  • 2019 A1 (P/PanSTARRS)
  • 2019 A2 (P/ATLAS)
  • 2019 A3 (P/PanSTARRS)
  • 2019 A4 (P/PanSTARRS)
  • 2019 A5 (PanSTARRS)
  • 2019 A6 (P/Lemmon-PanSTARRS)
  • 2019 A7 (P/PanSTARRS)
  • 2019 A8 (P/PanSTARRS)
  • 2019 A9 (PanSTARRS)
  • A/2019 AB4 [A/PanSTARRS]
  • 2019 B1 (Africano)
  • 2019 B2 (P/Groeller)
  • 2019 B3 (PanSTARRS)
  • A/2019 C1 [ATLAS]
  • 2019 D1 (Flewelling)
  • 2019 D2 (P/Spacewatch)
  • 2019 E1 (P/Scotti)
  • 2019 E2 (P/McNaught)
  • 2019 E3 (ATLAS)
  • A/2019 EJ3 [A/Catalina]
  • 2019 F1 (ATLAS-Africano)
  • 2019 F2 (ATLAS)
  • 2019 G1 (P/PanSTARRS)
  • A/2019 G2 [A/PanSTARRS]
  • A/2019 G3 [A/PanSTARRS]
  • A/2019 G4 [A/PanSTARRS]
  • 2019 GG21 (P/PanSTARRS)
  • 2019 GN22 (P/PanSTARRS)
  • 2019 H1 (NEOWISE)
  • 2019 J1 (Lemmon)
  • 2019 J2 (Palomar)
  • 2019 J3 (ATLAS)
  • 2019 JU6 (ATLAS)
  • 2019 K1 (ATLAS)
  • 2019 K2 (P/LINEAR-Spacewatch)

  • 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, 2019 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 (P/ATLAS)
    A 19th magnitude comet was discovered in images taken with the 0.5m Schmidt at Haleakala on January 4.48 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-A126, 2019 January 8]. The comet was at perihelion at 3.5 au in 2018 November and has a period of around 14 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, 2019 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, 2019 January 17]  The comet has a relatively short period of 4.2 years and was at perihelion at 2.4 au in 2018 December.
    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, 2019 January 17]  The comet is at perihelion at 6.3 au in 2019 June and has a period of around 100 years.
    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, 2019 January 17]  The comet has a period of around 12 years and was at perihelion at 1.9 au in 2018 August.
    2019 A7 (P/PanSTARRS)
    A 20th magnitude comet was discovered in PanSTARRS 1 images taken with the 1.8m Ritchey-Chretien on January 8.38.  There were prediscovery observations from PanSTARRS 1 in 2018 October and November. It was placed on the PCCP as P10LcVo.  [CBET 4605, MPEC 2019-B66, 2019 January 23]  The comet has a period of around 5.7 years and was at perihelion at 2.7 au in 2018 January.
    2019 A8 (P/PanSTARRS)
    A 21st magnitude comet was discovered in PanSTARRS 1 images taken with the 1.8m Ritchey-Chretien on January 11.64.  It was placed on the PCCP as P10LqGV.  [CBET 4608, MPEC 2019-C20, 2019 February 4]  The comet currently has a period of around 5.9 years and was at perihelion at 1.9 au in 2018 August.
    2019 A9 (PanSTARRS)
    A 20th magnitude object was discovered in PanSTARRS 1 images taken with the 1.8m Ritchey-Chretien on January 14.27.  It was placed on the PCCP as P10Lwea. It was subsequently shown to have weak cometary features. There were prediscovery PanSTARRS images from December 18. [CBET 4610, MPEC 2019-C53, 2019 February 7]  The comet is at perihelion at 1.4 au in 2019 July.
    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.
    2019 B1 (Africano)
    Brian Africano discovered a comet of 18th magnitude in Catalina Sky Survey images taken with the 0.68m Schmidt on January 19.48. Peter Birtwhistle was amongst the observers confirming the discovery, which was placed on the PCCP as C012RY1. [CBET 4604, MPEC 2019-B65, 2019 January 23]. The comet was at perihelion at 1.6 au in 2019 March.
    2019 B2 (P/Groeller)
    Hannes Groeller discovered a comet of 18th magnitude in Catalina Sky Survey images taken with the 0.68m Schmidt on January 26.31. Peter Birtwhistle was amongst the observers confirming the discovery, which was placed on the PCCP as C01N611. [CBET 4609, MPEC 2019-C21, 2019 February 4]. The comet is at perihelion at 2.4 au in 2019 June and has a period of around 7.6 years.
    2019 B3 (PanSTARRS)
    A 19th magnitude comet was discovered in PanSTARRS 1 images taken with the 1.8m Ritchey-Chretien on January 24.58.  It was placed on the PCCP as P10LPUO.  [CBET 4611, MPEC 2019-D41, 2019 February 27]  The comet is at perihelion at 6.8 au in 2021 January.
    A/2019 C1 [ATLAS]
    An 18th magnitude object was discovered in images taken with the 0.5m Schmidt at Mauna Loa on February 5.46 by the ATLAS (Asteroid Terrestrial-impact Last Alert System) team. There were pre-discovery images made in mid January from the Heleakala ATLAS. It had been posted on the PCCP as A10c3KV. [MPEC 2019-D42, 2019 February 27]. No cometary activity has been detected, however the object is in a long period orbit with perihelion at 6.6 au in 2020 May. It has therefore been given a cometary style asteroidal designation. It may show activity nearer perihelion, though this is only 0.7 au closer than its discovery distance.
    2019 D1 (Flewelling)
    Heather Flewelling discovered a 17th magnitude comet in images taken with the ATLAS (Asteroid Terrestrial-impact Last Alert System) 0.5m Schmidt at Mauna Loa on February 26.65. It had been posted on the PCCP as A10ceJ9. [CBET 4614, MPEC 2019-F53, 2019 March 21]. The comet is at perihelion at 1.6 au in 2019 May. It might be worth visual observers trying for it.
    2019 D2 (P/Spacewatch)
    This comet, missed at its 2012 apparition, was recovered by Gareth Williams in incidental astrometry reported by the Mount Lemmon Survey, which was then linked to a single-night detection on the NEOCP. R. Weryk (F51) also suggested the linkage when he reported that the same NEOCP object had a FWHM of ~1".8 (compared to 1".15 +/- 0".04 for nearby stars) and a ~4" tail to the east. The indicated delta-T correction to the prediction, by B. G. Marsden, on MPC 56954 is -1.29 days (in 2012, the correction was -0.61 days). [CBET 4616, MPEC 2019-G21, 2019 April 3].
    2019 E1 (P/Scotti)
    Erwin Schwab reported his recovery of 2003 L1 in images taken with the 1.0m reflector at the European Space Agency's Optical Ground Station at Teneriffe on March 9.11. The correction to T compared to the 2017 prediction on MPC 105247 is -0.39 days. [CBET 4612, MPEC 2019-E80, 2019 March 10]
    2019 E2 (P/McNaught)
    Erwin Schwab reported his recovery of 2005 Y2 in images taken with the 1.0m reflector at the European Space Agency's Optical Ground Station at Teneriffe on March 10.14. The correction to T compared to the 2011 prediction on MPC 75706 is +0.04 days. [CBET 4613, MPEC 2019-F27, 2019 March 18]
    2019 E3 (ATLAS)
    A 19th magnitude comet was discovered in images taken with the 0.5m Schmidt at Mauna Loa on March 5.43. by the ATLAS (Asteroid Terrestrial-impact Last Alert System) team. It had been posted on the PCCP as A10ckQ4. [CBET 4615, MPEC 2019-F54, 2019 March 21]. The comet is at perihelion at 10.3 au in 2023 November.
    A/2019 EJ3 [A/Catalina]
    An object of 19th magnitude was discovered in Catalina Sky Survey images taken with the 0.68m Schmidt on March 4.30. Peter Birtwhistle was amongst the observers confirming the discovery, which was placed on the PCCP as C04HO51. [MPEC 2019-F118, 2019 March 28]. No cometary activity has been detected, but the object is on a very comet-like orbit. It was only observed over a short arc from March 4 to 12 and so the orbit remains uncertain. The object was at perihelion at 1.1 au in 2019 March and has a period of over 500 years in a retrograde orbit. JPL classify it as an Amor NEO asteroid, with an Earth MOID of 0.1 au.
    2019 F1 (ATLAS-Africano)
    ATLAS reported a possible 18th magnitude NEO on March 28.52, but it didn't have a high score and was not posted on the NEOCP. Brian Africano discovered the same object as a comet of 18th magnitude in Mt Lemmon Survey images taken with the 1.5m reflector on March 29.42. It was placed on the PCCP as C012RY1. [CBET 4619, 2019 April 10, MPEC 2019-G124, 2019 April 9]. The comet is at perihelion at 3.6 au in 2021 June.
    2019 F2 (ATLAS)
    A 18th magnitude comet was discovered in images taken with the 0.5m Schmidt at Mauna Loa on March 26.31 by the ATLAS (Asteroid Terrestrial-impact Last Alert System) team. There were pre-discovery images made in February. It had been posted on the PCCP as A10cu6N. [CBET 4620, MPEC 2019-H29, 2019 April 22]. The comet is at perihelion at 2.2 au in 2019 September and has a period of around 70 years.
    2019 G1 (P/PanSTARRS)
    A 23rd magnitude comet was discovered in PanSTARRS 1 images taken with the 1.8m Ritchey-Chretien on April 3.51. Once the provisional orbit was better known it was possible for the PanSTARRS team to find prediscovery PanSTARRS observations from 2019 February, 2018 (when it was stellar) and 2011 (also stellar). There were also Mt Lemmon observations from 2019 March. With these observations, Gareth Williams then found further images from 2009 by Spacewatch and Purple Mountain Observatory. The comet was designated as 2011 O2 for the 2009 return. It was placed on the PCCP as P10MA2B.  [CBET 4610, 2019 April 10, MPEC 2019-G123, 2019 April 9]  The comet has a period of 9.6 years and was at perihelion at 3.0 au in 2009 October and 2019 June. It has a Jupiter MOID of 0.29 au and approached the planet to within 0.46 au in 1978 February; it will make a more distant approach in 2023, but a closer one has to wait until 2163.
    A/2019 G2 [PanSTARRS]
    PanSTARRS discovered an asteroid in images taken with the 1.8m Ritchey-Chretien on April 2.44. The object, classified as a Parabolic Asteroid, is at perihelion at 2.3 au in 2019 December and has a retrograde parabolic orbit with a Jupiter MOID of 0.20 au. It was placed on the PCCP as P10Mmzj. No cometary activity has been detected.
    A/2019 G3 [PanSTARRS]
    PanSTARRS discovered an asteroid in images taken with the 1.8m Ritchey-Chretien on April 4.49. The object, classified as a Centaur, was at perihelion at 2.9 au in 2018 December and has a retrograde orbit with a period of around 70 years. It was placed on the PCCP as P10MC3w. No cometary activity has been detected.
    A/2019 G4 [PanSTARRS]
    PanSTARRS discovered an asteroid in images taken with the 1.8m Ritchey-Chretien on April 9.25. The object, classified as a TNO, was at perihelion at 5.9 au in 2018 November and has a retrograde orbit with a period of around 900 years. It was placed on the PCCP as P10N31R. No cometary activity has been detected.
    2019 GG21 (P/PanSTARRS)
    PanSTARRS discovered an asteroid in images taken with the 1.8m Ritchey-Chretien on April 4.40. The object was initially classified as a Centaur, and was at perihelion at 3.9 au in 2019 May and has a period of around 20 years. It was placed on the PCCP as P10MGql. Within a day of being given the asteroidal designation it was redesignated as a comet following the detection of a tail. [CBET 4621, MPEC 2019-H44, 2019 April 23]
    2019 GN22 [A/KMTN]
    An object discovered by the Korea Microlensing Telescope Network-CTIO with the 1.6-m f/3.22 reflector on April 5.1 was posted on the PCCP as JA0004. No cometary activity has been detected. It is a distant Centaur, with perihelion at 11.6 au in 2027 November.
    2019 H1 (NEOWISE)
    An 18th magnitude cometary object was discovered from the NEOWISE satellite on April 18.9. [MPEC 2019-J24, CBET 4623, 2019 May 4] It was posted on the PCCP as N00epwh. The comet was at perihelion at 1.8 au in 2019 April.
    2019 J1 (Lemmon)
    Richard Kowalski and David Rankin discovered a comet of 18th magnitude in Mt Lemmon Survey images taken with the 1.5m reflector on May 4.45. [CBET 4625, 2019 May 14, MPEC 2019-J122, 2019 May 12]. It was placed on the PCCP as C0M96K2. The comet was at perihelion at 2.5 au in 2019 April.
    2019 J2 (Palomar)
    The Palomar Transient Factory discovered a 17th magnitude comet on May 9.47 with the 1.2m Oschin Schmidt.  Following posting on the PCCP they found pre-discovery images from April 27.5. [CBET 4626, 2019 May 14, MPEC 2019-J123, 2019 May 13]. It was placed on the PCCP as ZTF037w. It will be at perihelion at 1.7 in 2019 July.
    2019 J3 (ATLAS)
    A 19th magnitude comet was discovered in images taken with the 0.5m Schmidt at Haleakala on May 14.54 by the ATLAS (Asteroid Terrestrial-impact Last Alert System) team, and initially reported as an NEO candidate. It had been posted on the PCCP as A10dEHr. [CBET 4630, MPEC 2019-K14, 2019 May 23]. The comet is at perihelion at 2.4 au in 2019 August and has a period of around 100 years.
    2019 JU6 (ATLAS)
    A 19th magnitude object was discovered in images taken with the 0.5m Schmidt at Haleakala on May 12.57 by the ATLAS (Asteroid Terrestrial-impact Last Alert System) team. Subsequently other observers have noted cometary features and it has been re-designated. [CBET 4631, MPEC 2019-K18, 2019 May 24]. The comet is at perihelion at 2.0 au in 2019 June.
    2019 K1 (ATLAS)
    A 17th magnitude comet was discovered in images taken with the 0.5m Schmidt at Mauna Loa on May 16.48 by the ATLAS (Asteroid Terrestrial-impact Last Alert System) team, but apparently reported to the MPC without any details. It had been posted on the PCCP as A10dGSV. [CBET 4629, MPEC 2019-K13, 2019 May 23]. The comet is at perihelion at 2.0 au in 2020 February. It passed 1.2 au from Jupiter in 2019 February.
    2019 K2 (P/LINEAR-Spacewatch)
    Gareth Williams found images of 2000 S4 (P/LINEAR-Spacewatch) in incidental astrometry submitted by PanSTARRS and the Mt Lemmon Survey taken on May 29.57 (PanSTARRS) and June 1.44 (Mt Lemmon). The indicated delta-T correction to the prediction on MPC 102107 is +0.25 days.
    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