BAA Comet Section : Comets discovered in 2017

Updated 2017 May 24


  • 2017 A1 (PanSTARRS)
  • 2017 A2 (348P/PanSTARRS)
  • 2017 A3 (Elenin)
  • 2017 AX13 [A/PanSTARRS]
  • 2017 B1 (349P/Lemmon)
  • 2017 B2 (350P/McNaught)
  • 2017 B3 (LINEAR)
  • 2017 B4 (P/PanSTARRS)
  • 2017 C1 (NEOWISE)
  • 2017 C2 (PanSTARRS)
  • 2017 CW32 [A/Mt Lemmon]
  • 2017 CX33 [A/PanSTARRS]
  • 2017 D1 (P/Fuls)
  • 2017 D2 (Barros)
  • 2017 D3 (ATLAS)
  • 2017 D4 (P/PanSTARRS)
  • 2017 D5 (PanSTARRS)
  • 2017 DW108 [A/LINEAR]
  • 2017 E1 (Borisov)
  • 2017 E2 (Tsuchinshan)
  • 2017 E3 (PanSTARRS)
  • 2017 E4 (Lovejoy)
  • 2017 E5 (Lemmon)
  • 2017 EM4 [A/Mt Lemmon]
  • 2017 F1 (Lemmon)
  • 2017 F2 (PanSTARRS)
  • 2017 FF63 [A/Mt Lemmon]
  • 2017 FM64 [A/PanSTARRS]
  • 2017 FP64 [A/NEOWISE]
  • 2017 FA157 [A/PanSTARRS]
  • 2017 FU158 [A/NEOWISE]
  • 2017 G1 (P/PanSTARRS)
  • 2017 G2 (P/PanSTARRS)
  • 2017 G3 (PanSTARRS)
  • 2017 GC8 [A/PanSTARRS]
  • 2017 GD8 [A/PanSTARRS]
  • 2017 HW3 [A/Mt Lemmon]
  • 2017 K1 (PanSTARRS)
  • 2017 K2 (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 new and periodic comets in 2017 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.


    2017 A1 (PanSTARRS)
    A 19th magnitude comet was discovered in PanSTARRS 1 images taken with the 1.8m Ritchey-Chretien on January 2.33. [CBET 4340, MPEC 2017-A31, 2017 January 6] The comet is at perihelion at 2.3 au in 2017 May.
    2017 A2 (348P/PanSTARRS)
    A 21st magnitude comet was discovered in PanSTARRS 1 images taken with the 1.8m Ritchey-Chretien on January 2.58. It was then subsequently linked to images found in PanSTARRS and Mt Lemmon data from 2011 January, at which return it was given the designation 2011 A5. [CBET 4341, MPEC 2017-A32, 2017 Janaury 6] The comet was at perihelion at 2.2 au in 2016 June and has a period of 5.6 years.
    2017 A3 (Elenin)
    Leonid Elenin discovered an 18th magnitude comet with the ISON-SSO 0.4m reflector at Siding Spring on January 5.46. [CBET 4344, MPEC 2017-A75, 2017 January 11] The comet was at perihelion at 3.9 au in 2017 January and has a period of around 300 years.
    A/2017 AX13 [PanSTARRS]
    PanSTARRS discovered a 22nd magnitude asteroid in images taken with the 1.8m Ritchey-Chretien on January 2.58. [MPEC 2017-A67, 2017 January 9] The asteroid, classified as a Trans-Neptunian Object, was at perihelion at 3.2 au in 2016 January and has a period of around 200 years and is in a retrograde orbit with an inclination of 137°.
    2017 B1 (349P/Lemmon)
    A 21st magnitude object was discovered in PanSTARRS 1 images taken with the 1.8m Ritchey-Chretien on  January 26.59.  This was quickly linked to asteroid 2010 EY90 discovered by the Mt Lemmon Survey with the 1.5m reflector on 2010 March 14.24 and with pre-discovery Mt Lemmon images from 2017 January 7.   [CBET 4348, 4349, MPEC 2017-B82, 2017 January 27] The comet is at perihelion at 2.5 au in 2017 August and has a period of 6.75 years.
    2017 B2 (350P/McNaught)
    Jim Scotti recovered 2010 J5 (P/McNaught) with the Spacewatch 1.8m reflector on January 26.52. It returns to perihelion in 2018 January. [CBET 4352, MPEC 2017-B123, 2017 January 29/30]
    2017 B3 (LINEAR)
    A 19th magnitude object discovered by LINEAR (The 3.5m reflector Space Surveillance Telescope at the Atom Peak site) on January 26.43 was shown to have cometary features by astrometrists after posting on the PCCP. [CBET 4354, MPEC 2017-C43, 2017 February 4]  The comet has perihelion at 3.9 au in 2019 February.
    2017 B4 (P/PanSTARRS)
    A 21st magnitude comet was discovered in PanSTARRS 1 images taken with the 1.8m Ritchey-Chretien on January 28.39. [CBET 4355, MPEC 2017-C46, 2017 February 4] The comet was near perihelion at 2.8 au and has a period of 9.3 years.
    2017 C1 (NEOWISE)
    A 20th magnitude comet was discovered from the NEOWISE satellite on February 6.09. [CBET 4358, MPEC 2017-C82, 2017 February 12] The comet was at perihelion at 1.5 au in 2017 January and has a period of around 90 years.
    2017 C2 (PanSTARRS)
    A 20th magnitude comet was discovered in PanSTARRS 1 images taken with the 1.8m Ritchey-Chretien on February 4.26. [CBET 4362, MPEC 2017-D22, 2017 February 19] The comet was at perihelion at 2.4 au in 2017 January and has a period of about 1400 years.
    A/2017 CW32 [Mt Lemmon]
    The Mt Lemmon Survey discovered an asteroid in images taken with the 1.5m reflector on February 2, which was posted on the PCCP. There is no evidence for cometary activity. The asteroid is classified as an Unusual Object by the MPC and as a TNO by JPL. It is at perihelion at 3.0 au in 2017 May and has a retrograde orbit with a period of around 2700 years. It was placed on the PCCP as YCAD73A. In March it appeared on the PCCP for a second time, with the id of P10zOqm.
    A/2017 CX33 [PanSTARRS]
    PanSTARRS discovered a 22nd magnitude asteroid in images taken with the 1.8m Ritchey-Chretien on February 1.42. [MPEC 2017-D39, 2017 February 24] The asteroid, classified as a Trans-Neptunian Object, is at perihelion at 10.4 au in 2017 April and has a period of around 600 years. It was placed on the PCCP as P10zfMW.
    2017 D1 (P/Fuls)
    D Carson Fuls discovered a 20th magnitude comet in Mt Lemmon Survey images taken with the 1.5m reflector on February 21.35. Following this, pre-discovery images were found in PanSTARRS data from 2015 and 2016, and Mt Lemmon data from 2016 November. [CBET 4365, MPEC 2017-E04, 2017 March 1] The comet was at perihelion at 2.7 au in 2016 June and has a period of 10.5 years.
    2017 D2 (Barros)
    Brazilian amateur astronomer Joćo Ribeiro de Barros discovered a 17th magnitude comet in images taken with the 0.45m f/2.9 reflector of the SONEAR observatory on February 23.31. [CBET 4366, MPEC 2017-E05, 2017 March 1] The comet is at perihelion at 2.5 au in 2017 July.
    2017 D3 (ATLAS)
    An 18th magnitude comet was discovered in images taken with the 0.5m Schmidt at Haleakala on February 23.61. [CBET 4367, MPEC 2017-E06, 2017 March 1]. The comet was at perihelion at 5.0 au in 2017 April.
    2017 D4 (P/PanSTARRS)
    A 21st magnitude comet was discovered in PanSTARRS 1 images taken with the 1.8m Ritchey-Chretien on February 25.44. There were pre-discovery PanSTARRS images from January, and Mt Lemmon ones from February. [CBET 4368, MPEC 2017-E07, 2017 March 1] The comet was at perihelion at 2.8 au in 2016 September and has a period of around 20 years.
    2017 D5 (PanSTARRS)
    A 21st magnitude comet was discovered in PanSTARRS 1 images taken with the 1.8m Ritchey-Chretien on February 23.24. There were pre-discovery PanSTARRS images from February 10.32. It had been posted on the NEOCP as P10zKZZ. [CBET 4378, MPEC 2017-G04, 2017 April 2] The comet was at perihelion at 2.2 au in 2017 January and has a period of around 1000 years.
    A/2017 DW108 [LINEAR]
    A 20th magnitude asteroid was discovered in images taken with the Space Surveillance Telescope 3.5m reflector at the Atom site on February 22.16. [MPEC 2017-E02, 2017 March 1] The asteroid is classified as an Apollo asteroid and is at perihelion at 0.5 au in 2017 April. It has a period of 3.8 years, with an Earth MOID of 0.037 au. It will pass 0.086 au from the Earth on March 7 and 0.014 au from Venus on March 25. David Seargent notes that the orbit has similarities with that of D/Helfenzreider, seen in 1766.
    2017 E1 (Borisov)
    Gennady Borisov discovered a 17th magnitude comet on March 1.10 with the 0.4-m f/2.3 astrograph at the MARGO observatory, near Nauchnij, Crimea. [CBET 4369, MPEC 2017-E42, 2017 March 4] The comet was at perihelion at 0.9 au in April. Unfortunately the circumstances are not good and the comet is not predicted to get brighter than 14th magnitude.
    2017 E2 (Tsuchinshan)
    A comet was discovered at the Purple Mountain Observatory, XuYi station with the 1.04-m f/1.8 Schmidt on March 1.82.  It had been posted on the NEOCP as X49504.  [CBET 4370, MPEC 2017-E57, 2017 March 7] The discovery MPEC gave the comet name as XuYi, but this was subsequently changed to Tsuchinshan.  The comet was at perihelion at 2.4 au in 2016 May and has a period of around 100 years.
    2017 E3 (PanSTARRS)
    A 19th magnitude comet was discovered in PanSTARRS 1 images taken with the 1.8m Ritchey-Chretien on March 7.53. [CBET 4372, MPEC 2017-E85, 2017 March 13] The comet is at perihelion at 5.9 au in 2017 June.  The orbit is not yet well determined.
    2017 E4 (Lovejoy)
    Terry Lovejoy discovered a 15th magnitude comet in images taken with his 0.36m f1.9 Schmidt-Cassegrain on March 9.68. [CBET 4373, MPEC 2017-E86, 2017 March 13] The comet will be at perihelion at 0.5 au in 2017 April. It is apparently intrinsically very faint and may get no brighter than 14th magnitude. It is however possible that it has a faint outer coma not readily obvious in astrometric CCD images and may be brighter visually.  The comet was soon shown to be significantly brighter than indicated by the CCD observations, with Juan Jose Gonzalez estimating it at 8.6 in his 0.2m SCT on March 20.21.
    2017 E5 (Lemmon)
    A 20th magnitude object was discovered in Mt Lemmon Survey images taken with the 1.5m reflector on March 4.41. It had been posted on the NEOCP as YE832BC. [CBET 4379, MPEC 2017-G05, 2017 April 2] The comet was at perihelion at 1.8 au in 2016 June and has a period of 8000 years.
    A/2017 EM4 [Mt Lemmon]
    The Mt Lemmon Survey discovered a 20th magnitude asteroid in images taken with the 1.5m reflector on March 8.42. [MPEC 2017-E95, 2017 March 13] The asteroid is classified as a Centaur by JPL. It was at perihelion at 2.6 au in 2017 January and has a high inclination orbit with a period of around 100 years. It has a Jupiter MOID of 2.5 au and a Tisserand invariant of 0.51.
    2017 F1 (Lemmon)
    A 20th magnitude object was discovered in Mt Lemmon Survey images taken with the 1.5m reflector on March 20.19. It had been posted on the NEOCP as YF982D7. [CBET 4380, MPEC 2017-G06, 2017 April 2] The comet will reach perihelion at 4.5 au in 2017 November or December.
    2017 F2 (PanSTARRS)
    A 21st magnitude comet was discovered in PanSTARRS 1 images taken with the 1.8m Ritchey-Chretien on March 31.41. [CBET 4381, MPEC 2017-G56, 2017 April 6] The comet is at perihelion at 7.0 au in 2017 October.  Some aspects of the orbit are not yet well determined.
    A/2017 FF63 [Mt Lemmon]
    The Mt Lemmon Survey discovered a 21st magnitude asteroid in images taken with the 1.5m reflector on March 19.34. [MPEC 2017-F82, 2017 March 23] The asteroid is classified as a member of the Outer Main-belt by JPL. It was at perihelion at 1.6 au in 2017 February and has a period of around 6 years. The orbit has a Jupiter MOID of 0.22 au and a Tisserand invariant of 2.78.
    A/2017 FM64 [PanSTARRS]
    PanSTARRS discovered a 22nd magnitude asteroid in images taken with the 1.8m Ritchey-Chretien on March 19.33. [MPEC 2017-F101, 2017 March 24] The asteroid, classified as an Outer Main-belt Asteroid, was at perihelion at 1.5 au in 2017 February and has a period of around 6.2 years. The orbit has a Jupiter MOID of 0.06 au and a Tisserand invariant of 2.87.
    A/2017 FP64 [NEOWISE]
    A 19th magnitude asteroid was discovered from the NEOWISE satellite on March 20.97. [MPEC 2017-F104, 2017 March 24] The asteroid, classified as an Amor, is at perihelion at 1.3 au in 2017 April and has a period of around 5.7 years. The orbit has a Jupiter MOID of 0.06 au and a Tisserand invariant of 2.84.
    A/2017 FA157 [PanSTARRS]
    PanSTARRS discovered a 22nd magnitude asteroid in images taken with the 1.8m Ritchey-Chretien on March 29.40. [MPEC 2017-G32, 2017 April 4] The asteroid, classified as an Outer Main-belt Asteroid, was at perihelion at 1.5 au in 2017 February and has a period of around 6.2 years. The orbit has a Jupiter MOID of 0.03 au and a Tisserand invariant of 2.86.
    A/2017 FU158 [NEOWISE]
    A 21st magnitude asteroid was discovered from the NEOWISE satellite on March 26.96. [MPEC 2017-G88, 2017 April 14] The asteroid, classified as an Amor, was at perihelion at 1.2 au in 2017 January and has a period of around 6.8 years. The orbit has a Jupiter MOID of 0.49 au and a Tisserand invariant of 2.58.
    2017 G1 (P/PanSTARRS)
    A 22nd magnitude comet was discovered in PanSTARRS 1 images taken with the 1.8m Ritchey-Chretien on April 1.46. There were also pre-discovery images from March 25. [CBET 4382, MPEC 2017-G33, 2017 April 6] The comet was at perihelion at 2.6 au in 2016 May and has a period of about 22 years. It is a Jupiter-family Comet and has a MOID of 0.29 au.
    2017 G2 (P/PanSTARRS)
    A 20th magnitude comet was discovered in PanSTARRS 1 images taken with the 1.8m Ritchey-Chretien on April 3.41. There were also pre-discovery images from March 18. [CBET 4384, 4385, MPEC 2017-H41, 2017 April 21] The comet is at perihelion at 2.8 au in 2017 June and has a period of about 23 years. It is a Jupiter-family Comet and has a MOID of 0.xx au. It was placed on the PCCP as P10AMVu.
    2017 G3 (PanSTARRS)
    A 20th magnitude comet was discovered in PanSTARRS 1 images taken with the 1.8m Ritchey-Chretien on April 7.57. [CBET 4386, MPEC 2017-H42, 2017 April 21] The comet was near perihelion at 2.6 au. Some aspects of the orbit are not yet well determined. It was placed on the PCCP as P10APWl.
    A/2017 GC8 [PanSTARRS]
    PanSTARRS discovered a 22nd magnitude asteroid in images taken with the 1.8m Ritchey-Chretien on April 1.46. [MPEC 2017-H32, 2017 April 21] The asteroid, classified as a Centaur, was at perihelion at 2.6 au in 2017 March and has a period of around 33 years. The orbit has a Jupiter MOID of 0.49 au and a Tisserand invariant of 2.37. It was placed on the PCCP as P10AH43.
    A/2017 GD8 [PanSTARRS]
    PanSTARRS discovered a 21st magnitude asteroid in images taken with the 1.8m Ritchey-Chretien on April 1.54. [MPEC 2017-H33, 2017 April 21] The asteroid, classified bu JPL as a Trans-Neptunian Object, was at perihelion at 2.3 au in 2017 February and has a period of around 300 years. It was placed on the PCCP as P10AHWa.
    A/2017 HW3 [Mt Lemmon]
    The Mt Lemmon Survey discovered a 21st magnitude asteroid in images taken with the 1.5m reflector on April 22.31. [MPEC 2017-H69, 2017 April 26] The asteroid is classified as a member of the Outer Main-belt by JPL. It is at perihelion at 1.3 au in 2017 June and has a period of around 5.7 years. The orbit has a Jupiter MOID of 0.21 au and a Tisserand invariant of 2.75.
    2017 K1 (PanSTARRS)
    A 20th magnitude comet was discovered in PanSTARRS 1 images taken with the 1.8m Ritchey-Chretien on May 21.40. [CBET 4392, MPEC 2017-K34, 2017 May 24] The comet is at perihelion at 6.6 au in 2018 October. The error bars on the perihelion distance are 5.2 au and 1729 days on the date of perihelion according to JPL.
    2017 K2 (PanSTARRS)
    A 21st magnitude comet was discovered in PanSTARRS 1 images taken with the 1.8m Ritchey-Chretien on May 21.49. [CBET 4393, MPEC 2017-K35, 2017 May 24] The comet is at perihelion at 9.9 au in 2027 January. The comet was over 20 au from the Sun at discovery. The error bars on the perihelion distance are 42 au and 18900 days on the date of perihelion according to JPL.
    Ephemerides of current comets are available on the CBAT ephemeris page and positions of newly discovered comets are on the Possible Comet Confirmation Page.
    More information on LINEAR. A list of comets discovered by selected search programs.
    Published by Jonathan Shanklin. Jon Shanklin - jds@ast.cam.ac.uk