BAA Comet Section : Comets discovered in 2016

Updated 2021 August 31


  • 2016 A1 (PanSTARRS)
  • 2016 A2 (P/Christensen)
  • 2016 A3 (P/PanSTARRS)
  • 2016 A4 (334P/NEAT)
  • 2016 A5 (PanSTARRS)
  • 2016 A6 (PanSTARRS)
  • 2016 A7 (P/PanSTARRS)
  • 2016 A8 (LINEAR)
  • 2016 A9 (335P/Gibbs)
  • A/2016 AF165 [LINEAR]
  • 2016 B1 (NEOWISE)
  • 2016 B2 (336P/McNaught)
  • 2016 BA14 (P/PanSTARRS)
  • A/2016 BJ81 [Mt Lemmon]
  • 2016 C1 (PanSTARRS)
  • 2016 C2 (NEOWISE)
  • A/2016 CK246 [Mt Lemmon]
  • A/2016 CO264 [PanSTARRS]
  • 2016 E1 (PanSTARRS)
  • 2016 E2 (Kowalski)
  • A/2016 EJ203 [Mt Lemmon]
  • 2016 G1 (P/PanSTARRS)
  • 2016 GE216 (337P/WISE)
  • 2016 J1 (P/PanSTARRS)
  • 2016 J2 (Denneau)
  • 2016 J3 (P/STEREO)
  • 2016 K1 (LINEAR)
  • 2016 KA (Catalina)
  • A/2016 LX48 [PanSTARRS]
  • 2016 M1 (PanSTARRS)
  • 2016 M2 (339P/Gibbs)
  • 2016 N1 (338P/McNaught)
  • 2016 N2 (340P/Boattini)
  • 2016 N3 (341P/Gibbs)
  • 2016 N4 (MASTER)
  • 2016 N5 (342P/SOHO)
  • 2016 N6 (PanSTARRS)
  • A/2016 NM56 [PanSTARRS]
  • 2016 P1 (P/PanSTARRS)
  • 2016 P2 (351P/Wiegert-PanSTARRS)
  • 2016 P3 (343P/NEAT-LONEOS)
  • 2016 P4 (PanSTARRS)
  • A/2016 PN66 [Crni Vrh]
  • 2016 Q1 (344P/Read)
  • 2016 Q2 (PanSTARRS)
  • 2016 Q3 (345P/LINEAR)
  • 2016 Q4 (Kowalski)
  • 2016 R1 (346P/Catalina)
  • 2016 R2 (PanSTARRS)
  • 2016 R3 (Borisov)
  • 2016 R4 (P/Gibbs)
  • 2016 S1 (P/PanSTARRS)
  • 2016 SV (347P/PanSTARRS)
  • 2016 T1 (Matheny)
  • 2016 T2 (Matheny)
  • 2016 T3 (PanSTARRS)
  • 2016 U1 (NEOWISE)
  • 2016 U2 (PanSTARRS)
  • A/2016 UX41 [PanSTARRS]
  • A/2016 US109 [Mt Lemmon]
  • 2016 VZ18 (PanSTARRS)
  • A/2016 VY17 [Mt Lemmon]
  • A/2016 WF9 [NEOWISE]
  • 2016 WM48 (Lemmon)
  • 2016 X1 (Lemmon)
  • A/2016 YB13 [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 2016 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 do publish the errors, whereas the MPECs do not.


    2016 A1 (PanSTARRS)
    A 19th magnitude comet was discovered in PanSTARRS 1 images taken with the 1.8m Ritchey-Chretien on January 1.54. [CBET 4232, MPEC 2016-A61, 2016 January 7] The comet is at perihelion at 5.3 au in 2017 November.  JPL give a Jupiter MOID of 0.07 au, but give no close approaches.  It was reported on the PCCP as ZA3CF9B in 2018 January.
    2016 A2 (P/Christensen)
    Eric Christensen discovered a 20th magnitude comet in images taken with the Mt Lemmon Survey 1.5m reflector on January 2.48.  [CBET 4233, MPEC 2016-A62, 2016 January 7] The comet was at perihelion at 3.4 au in 2015 June and has a period of around 10 years. 
    2016 A3 (P/PanSTARRS)
    A 21st magnitude comet was discovered in PanSTARRS 1 images taken with the 1.8m Ritchey-Chretien on January 4.54. [CBET 4234, MPEC 2016-A63, 2016 January 7] The comet is at perihelion at 4.8 au in 2017 April and has a period of around 20 years.
    2016 A4 (334P/NEAT)
    Comet 2001 F1 was independently recovered at the Piszkesteto Station of Konkoly Observatory on January 7.90 and at the European Space Agency's Optical Ground Station, Tenerife on January 10.10. [CBET 4237, MPEC 2016-A105, 2016 January 11] The indicated correction to the prediction by S. Nakano in the ICQ's 2014 Comet Handbook is Delta(T) = -0.36 day.
    2016 A5 (PanSTARRS)
    A 22nd magnitude comet was discovered in PanSTARRS 1 images taken with the 1.8m Ritchey-Chretien on January 9.49. [CBET 4238, MPEC 2016-B09, 2016 January 16] The comet was at perihelion at 2.9 au in 2015 June.
    2016 A6 (PanSTARRS)
    A 21st magnitude comet was discovered in PanSTARRS 1 images taken with the 1.8m Ritchey-Chretien on January 13.44. [CBET 4239, MPEC 2016-B34, 2016 January 19] The comet was at perihelion at 2.4 au in 2015 November.
    2016 A7 (P/PanSTARRS)
    A 22nd magnitude comet was discovered in PanSTARRS 1 images taken with the 1.8m Ritchey-Chretien on January 14.65. [CBET 4240, MPEC 2016-B62, 2016 January 22] The comet was at perihelion at 2.2 au in 2016 February and has a period of 11 years.
    2016 A8 (LINEAR)
    A 20th magnitude object discovered by LINEAR (The 3.5m reflector Space Surveillance Telescope at the Atom site) on January 14.14 was shown to have cometary features by astrometrists after posting on the PCCP. [CBET 4245, MPEC 2016-B84, 2016 January 29]  The comet has perihelion at 1.9 au in 2016 August and a period of around 200 years.  Although the discovery magnitude suggests that it will get to 15th magnitude, it could do better around the time of perihelion and may be worth checking visually.  This prediction was shown to be correct when the comet was observed visually from late July and reached 11th magnitude at the end of August.
    2016 A9 (335P/Gibbs)
    Comet 2008 Y2 was recovered at the European Space Agency's Optical Ground Station, Tenerife on January 10.26. [CBET 4253, MPEC 2016-C42, 2016 February 5] The comet was close to the predicted orbit.
    A/2015 AF165 [LINEAR]
    The Space Surveillance Telescope at the Atom site discovered a 20th magnitude asteroid in images taken with the 3.5m f/1 reflector on January 12.41. [MPEC 2016-A164, 2016 January 15] The asteroid, classified as an Amor type NEO, is at perihelion at 1.3 au in 2016 January and has a period of around 6 years. The orbit has a Tisserand criterion with respect to Jupiter of 2.82, with a Jupiter MOID of 0.16 and an earth MOID of 0.32 au.
    2016 B1 (NEOWISE)
    A 19th magnitude comet was discovered from the NEOWISE satellite on January 17.87. [CBET 4242, MPEC 2016-B63, 2016 January 22] The comet will reach perihelion at 3.2 au in 2016 December.
    2016 B2 (336P/McNaught)
    Gareth Williams found astrometry of 2006 G1 in PanSTARRS data from January 18.57 and February 14. The comet reaches perihelion 0.1 days earlier than predicted. [CBET 4258, MPEC 2016-C201, 2016 February 15] (Note the very large number of MPECs issued in the first half of February !)
    2016 BA14 (P/PanSTARRS)
    A 19th magnitude asteroid discovered in PanSTARRS 1 images taken with the 1.8m Ritchey-Chretien on January 22.34, was subsequently shown to have a faint tail. Pre-discovery PanSTARRS images were then found from 2015 December. Denis Denisenko suggests that the orbit is very similar to that of 252P/LINEAR. [CBET 4257, MPEC 2016-C192, 2016 February 15] The comet was at perihelion at 1.0 au in 2016 March and passed 0.024 au from the Earth on March 22. This is nearly optimum for a close approach as the MOID is 0.017 au; the Jupiter MOID is 0.094 au. It has a period of 5.3 years. It will make another close approach to the Earth in 2048, but there are no very close approaches to Jupiter over the century centred on the present. Although intrinsically very faint, the comet reached 13th magnitude at closest approach, when it was moving rapidly across northern skies.
    A/2015 BJ81 [Mt Lemmon]
    The Mt Lemmon Survey discovered a 20th magnitude asteroid in images taken with the 1.5m reflector on January 28.36. [MPS 682769] The asteroid, classified as a Centaur by JPL and a Distant Object by the MPC, was at perihelion at 5.0 au in 2016 December and has a period of 29 years. The orbit has a Tisserand criterion with respect to Jupiter of 2.86, with a Jupiter MOID of 0.35 au.
    2016 C1 (PanSTARRS)
    A 20th magnitude comet was discovered in PanSTARRS 1 images taken with the 1.8m Ritchey-Chretien on February 12.50. [CBET 4256, MPEC 2016-C175, 2016 February 14] As expected for what was a distant object observed over only three days, JPL gave uncertainty figures of several years in the date of perihelion, several au in the perihelion distance, and equally large uncertainties in the angular elements.  The comet was at perihelion at 8.5 au in 2016 February.  
    2016 C2 (NEOWISE)
    A 19th magnitude comet was discovered from the NEOWISE satellite on February 8.50. [CBET 4260, MPEC 2016-D25, 2016 February 18] The comet was at perihelion at 1.6 au in 2016 April and has a period of around 500 years.
    A/2015 CK246 [Mt Lemmon]
    The Mt Lemmon Survey discovered a 21st magnitude asteroid in images taken with the 1.5m reflector on February 10.15. [MPEC 2016-C177, 2016 February 14] The asteroid, classified as an Amor type NEO, is at perihelion at 1.1 au in 2016 March and has a period of around 8 years. The orbit has a Tisserand criterion with respect to Jupiter of 2.49, with a Jupiter MOID of 0.21 au and an earth MOID of 0.15 au.
    A/2015 CO264 [PanSTARRS]
    PanSTARRS discovered a 22nd magnitude asteroid in images taken with the 1.8m Ritchey-Chretien on February 14.44. [MPEC 2016-D46, 2016 February 26] The asteroid, classified as a Trans-Neptunian Object, is at perihelion at 3.0 au in 2016 August and has a retrograde orbit with a period of around 300 years.
    2016 E1 (PanSTARRS)
    A 21st magnitude comet was discovered in PanSTARRS 1 images taken with the 1.8m Ritchey-Chretien on March 3.54. [CBET 4263, MPEC 2016-E113, 2016 March 11] The comet is at perihelion at 8.2 au in 2017 June.
    2016 E2 (Kowalski)
    Richard Kowalski discovered an 18th magnitude comet in images taken with the Mt Lemmon Survey 1.5m reflector on March 15.44.  [CBET 4266, MPEC 2016-F03, 2016 March 16] The comet was at perihelion at 1.1 au in 2016 February.
    A/2015 EJ203 [Mt Lemmon]
    The Mt Lemmon Survey discovered a 22nd magnitude asteroid in images taken with the 1.5m reflector on March 11.33. [MPEC 2016-J62, 2016 May 8] The asteroid, classified as a Trans-Neptunian Object, is at perihelion at 2.7 au in 2016 July and has a retrograde orbit with a period of around 500 years.
    2016 G1 (P/PanSTARRS)
    A 19th magnitude comet was discovered in PanSTARRS 1 images taken with the 1.8m Ritchey-Chretien on April 1.53. Gareth Williams identified pre-discovery astrometry in Mt Lemmon data from March 12.  [CBET 4269, MPEC 2016-G72, 2016 April 4] The comet is at perihelion at 2.0 au in 2017 January and has a period of around 4.1 years.
    2016 GE216 (337P/WISE)
    An apparently asteroidal object of 21st magnitude was discovered by PanSTARRS on April 10.58. It was linked to earlier observations and given a minor planet designation. PanSTARRS images taken in early June suggested that it was likely to be a comet. After this report had been received by the MPC, they received a report from Erwin Schwab on the recovery of 2010 N1 (P/WISE) and he later noted the identity with the asteroid. The indicated correction to the prediction by S. Nakano for P/2010 N1 is Delta(T) = -0.65 day. [CBET 4283, MPEC 2016-L36, 2016 June 5] The comet is at perihelion at 1.7 au in 2016 July and has a period of 6.0 years. It made a close (0.52 au) approach to Jupiter in 2013 June, which increased the perihelion distance from 1.49 au to its current value and also slightly lengthened the period.
    2016 J1 (P/PanSTARRS)
    A 21st magnitude comet was discovered in PanSTARRS 1 images taken with the 1.8m Ritchey-Chretien on May 5.46. Confirmatory images taken with the Canada-France-Hawaii telescope on May 6.43 showed a second comet in the field, moving in an identical fashion. This was designated component B. [CBET 4276, MPEC 2016-J90, 2016 May 8] The comets are at perihelion at 2.4 au in 2016 June and have a period of around 5.6 years.  It/they is a Main Belt Comet.
    2016 J2 (Denneau)
    Larry Denneau discovered a very diffuse, 18th magnitude, comet in images taken with the ATLAS project 0.5m Schmidt at Haleakala on May 6.24.  [CBET 4277, MPEC 2016-J91, 2016 May 8].  The comet was at perihelion in April at 1.5 au.
    2016 J3 (P/STEREO)
    Scott Ferguson reported a comet in STEREO H1 images from May 14 to Karl Battams on May 26. Man-To Hui measured the images and Battams sent the astrometry to the MPC who computed an orbit. Battams notes that strong forward scattering may have contributed to the comet's brightness, which reached around 8th magnitude. [CBET 4281, MPEC 2016-K41, 2016 May 31]. The comet was at perihelion on May 21 at 0.47 au and has a period of 7.7 years according to the MPC elements. It may be visible to imagers in the southern hemisphere, however the magnitude is extremely uncertain. The orbital elements are also extremely uncertain, and JPL give error bars of 1.0 au in the perihelion distance and 59 years in the period!
    2016 K1 (LINEAR)
    A 18th magnitude object discovered by LINEAR (The 3.5m reflector Space Surveillance Telescope at the Atom Peak site) on May 31.42 was shown to have cometary features by astrometrists after posting on the PCCP. [CBET 4282, MPEC 2016-L34, 2016 June 5]  The comet has perihelion at 2.3 au in 2016 July.
    2016 KA (Catalina)
    A 20th magnitude asteroid discovered by the Catalina Sky Survey with the 0.68m Schmidt on May 16.41 was found to show cometary features during follow-up astrometry, eg by Peter Birtwhistle. [CBET 4280, MPEC 2016-K34, 2016 May 29] The comet was at perihelion in February at 5.4 au.
    A/2016 LX48 [PanSTARRS]
    PanSTARRS discovered a 19th magnitude asteroid in images taken with the 1.8m Ritchey-Chretien on June 11.32. [MPEC 2016-L122, 2016 June 14] The asteroid, classified as an Apollo asteroid, is at perihelion at 1.0 au in 2016 August and has a period of around 5.9 years. It is also a PHA and NEO. It has a Jupiter MOID of 0.02 au and an Earth MOID of 0.01 au. It will pass 0.05 au from the Earth in mid September.
    2016 M1 (PanSTARRS)
    A 20th magnitude comet was discovered in PanSTARRS 1 images taken with the 1.8m Ritchey-Chretien on June 22.47. [CBET 4286, MPEC 2016-M18, 2016 June 24] The comet is at perihelion at 2.2 au in 2018 August. The comet could reach 8th magnitude in 2018 June and July, when it is a southern hemisphere object.
    2016 M2 (339P/Gibbs)
    Hirohisa Sato recovered 2009 K1 in images taken with the 0.5m iTelescope at Siding Spring on 2016 June 29.35. The comet reaches perihelion 0.2 days earlier than predicted. [CBET 4287, MPEC 2016-N13, 2016 July 3/4]
    2016 N1 (338P/McNaught)
    2008 J3 was recovered at the European Space Agency Optical Ground Station with the 1.0m reflector on July 2.18. The comet reaches perihelion 0.8 days earlier than predicted. [CBET 4288, MPEC 2016-N12, 2016 July 3/4]
    2016 N2 (340P/Boattini)
    A 20th magnitude comet was discovered in PanSTARRS 1 images taken with the 1.8m Ritchey-Chretien on July 4.50. R Weyrk of the PanSTARRS team suggested that it might be an accidental recovery of 2008 T1 and this was confirmed by Gareth Williams. The comet reaches perihelion 0.3 days later than predicted. [CBET 4289, MPEC 2016-N27, 2016 July 5]
    2016 N3 (341P/Gibbs)
    An 18th magnitude comet discovered during the Catalina Sky Survey with the 0.68-m Schmidt on July 15.45 was found to be the first observed return of 2007 R3. The comet reaches perihelion 0.48 days earlier than predicted. [CBET 4290, MPEC 2016-O265, 2016 July 18]
    2016 N4 (MASTER)
    An apparently asteroidal object of 17th magnitude found with the MASTER 0.4m reflector at Teneriffe on July 15.15 (and for a while designated as 2016 NZ38) was shown to have cometary features during follow-up astrometry by other observers. Hirohisa Sato computed an improved orbit and the comet has perihelion at 3.2 au in 2017 September and a period of around 800 years. [CBET 4291, MPEC 2016-O266, 2016 July 18]
    2016 N5 (342P/SOHO)
    A Kracht group comet discovered by Worachate Boonplod in SOHO C2 imagery from July 1 was linked to 2000 O3, 2005 W4 and 2011 E1. The comet has a period of 5.3 years and shows non-gravitational motion. [MPEC 2016-P77, 2016 August 10, CBET 4308, 2016 August 26]
    2016 N6 (PanSTARRS)
    A 21st magnitude comet was discovered in PanSTARRS 1 images taken with the 1.8m Ritchey-Chretien on June 27.40. It was soon posted on the PCCP, but it took another two months for the first orbit to be published. [CBET 4309, MPEC 2016-Q33, 2016 August 28] The comet is at perihelion at 2.7 au in 2018 July. The comet could reach 14th magnitude at perihelion.
    A/2016 NM56 [PanSTARRS]
    PanSTARRS discovered a 22nd magnitude asteroid in images taken with the 1.8m Ritchey-Chretien on July 14.57. [MPEC 2016-Q55, 2016 August 30] The asteroid, classified as an Trans-Neptunian Object, was at perihelion at 10.5 au in 2015 October and has a period of around 600 years and is in a retrograde orbit with an inclination of 144°.
    2016 P1 (P/PanSTARRS)
    A 22nd magnitude comet was discovered in PanSTARRS 1 images taken with the 1.8m Ritchey-Chretien on August 1.41. [CBET 4297, MPEC 2016-P119, 2016 August 14] The comet was at perihelion at 2.3 au in 2015 September and has a period of around 5.8 years.
    2016 P2 (351P/Wiegert-PanSTARRS)
    A 21st magnitude comet was discovered in PanSTARRS 1 images taken with the 1.8m Ritchey-Chretien on August 8.52, with pre-discovery images from July 9.58. [CBET 4298, MPEC 2016-P120, 2016 August 14] The comet was at perihelion at 3.1 au in 2015 November and has a period of 9.3 years.

    Further observations allowed linkage with an asteroid discovered by P A Wiegert with the 3.6m CFHT on 2007 September 14.27, and with an object in images from LONEOS in 1998 October.


    2016 P3 (343P/NEAT-LONEOS)
    A 20th magnitude comet was discovered in PanSTARRS 1 images taken with the 1.8m Ritchey-Chretien on August 12.48. Michael Meyer and Gareth Williams identified it with 2003 SQ215, and also found earlier PanSTARRS images from July 7, along with others taken by S. Maticic with the Crni Vrh 0.6-m f/3.3 Deltagraph on August 9. [CBET 4302, MPEC 2016-P122, 2016 August 14] The comet is returning to perihelion some 5 days earlier than previously predicted and will be at perihelion at 2.3 au in 2017 January. It has a period of 12.8 years.
    2016 P4 (PanSTARRS)
    A 22nd magnitude comet was discovered in PanSTARRS 1 images taken with the 1.8m Ritchey-Chretien on July 31.4. [CBET 4317, MPEC 2016-R88, 2016 September 8/9] It was on the PCCP for over a month. The comet is at perihelion at 5.9 au in 2016 October.
    A/2016 PN66 [Crni Vrh]
    A 19th magnitude asteroid was discovered in images taken at the Crni Vrh Observatory on August 14.07. The asteroid, classified as a Trans-Neptunian Object by JPL and as an Unusual Object by the MPC, was at perihelion at 2.9 au in 2016 October and has a period of around 180 years and is in a retrograde orbit with an inclination of 105°.
    2016 Q1 (344P/Read)
    Krisztian Sarneczky recovered 2005 S3 (P/Read) with the 0.6m Schmidt at Piszkesteto Station of Konkoly Observatory on August 27.04. [CBET 4310, MPEC 2016-Q52, 2016 August 30]. The comet returns to perihelion 0.5 days earlier than predicted.
    2016 Q2 (PanSTARRS)
    A 21st magnitude comet was discovered in PanSTARRS 1 images taken with the 1.8m Ritchey-Chretien on August 26.34. [CBET 4311, MPEC 2016-Q53, 2016 August 30] The comet is at perihelion at 7.1±0.3 au in 2021 May±2 months according to JPL.  The orbit is still uncertain and the latest MPEC orbit using similar observations is somewhat different and outside the published uncertainties of the JPL orbit.
    2016 Q3 (345P/LINEAR)
    A 19th magnitude comet discovered during the Mt Lemmon Survey with the 1.5m reflector on August 29.35 was linked to asteroid 2008 SH164 discovered by LINEAR on 2008 September 28.23. [CBET 4312, MPEC 2016-Q54, 2016 August 30] The comet was at perihelion at 3.2 au in 2016 July and has a period of 8.1 years.
    2016 Q4 (Kowalski)
    Rich Kowalski discovered a 19th magnitude comet in images taken with the Mt Lemmon Survey 1.5m reflector on August 30.25. There were pre-discovery images from PanSTARRS on July 11 and August 3. [CBET 4314, MPEC 2016-R18, 2016 September 1] The comet is at perihelion at 7.1 au in 2018 January and has a period of around 70 years. 
    2016 R1 (346P/Catalina)
    Comet 2007 T6 (P/Catalina) was recovered by Krisztian Sarneczky and P Szekely with the 0.6m Schmidt at Piszkesteto Station of Konkoly Observatory on September 1.08. It was not given a designation on the MPEC. It returns to perihelion 0.35 days earlier than predicted. [MPEC 2016-R19, 2016 September 2, CBET 4315, 2016 September 3 ]
    2016 R2 (PanSTARRS)
    A 19th magnitude comet was discovered in PanSTARRS 1 images taken with the 1.8m Ritchey-Chretien on August 30.63. [CBET 4318, MPEC 2016-R107, 2016 September 9] The comet was at perihelion at 2.6 au in 2018 May.  Early electronic magnitudes put the comet at 13th magnitude in late December 2016 and brightening quite rapidly.  This rate of brightening did not persist and it scarcely brightened over the next eight months. The observations are not a good fit to a steady curve, and it seems likely that the comet has periods of greater activity.  It was a couple of magnitudes brighter than the mean curve in 2018 September and continuted brightening into November even though its distance from the Sun was increasing.  It re-appeared on the PCCP in 2019 May/June as COR8032.

    Professional observations in 2017 December suggest that the comet is very rich in CO, and relatively poor in HCN.  It may be quite a large object as it was producing about a third the amount of CO compared to 1995 O1 (Hale-Bopp) at the same distance. [CBET 4464, 2017 December 24].
    2016 R3 (Borisov)
    Gennady Borisov discovered a 16th magnitude comet in images taken with the 0.3-m f/1.5 astrograph at the MARGO observatory, near Nauchnij, Crimea, on September 11.07. The object was confirmed by other astrometrists, including Peter Birtwhistle. [CBET 4321, MPEC 2016-S03, 2016 September 16] The comet was at perihelion at 0.4 au in October. Gareth Williams commented on the MPEC:
    The preliminary orbit for this object is being presented as a parabolic orbit, but the available observations are consistent with intermediate-period orbits with periods as short as 50 years, possibly even 30 years. As suggested by internal MPC checking routines (and subsequently by M. Meyer), the orbit of this object is very similar to that of 1915 R1 (Mellish), for which a parabolic orbit was published by Einaarson and Alter (1915, Lick Obs. Bull. 8, 151) based on only three observations (which was then compared to other available observations). A new orbit for C/1915 R1, based on all seven available observations was computed.

    Attempts by the Gareth Williams (and S. Nakano) to link the 1915 and 2016 apparitions have not been successful. Attempts were made for n = 0, 1, 2 and 3 intervening (missed) returns between the 1915 and 2016 perihelion passages. The two comets appear not to be the same object, but the possibility of a common origin will require further investigation.

    Unfortunately the circumstances of the apparition were about as poor as is possible, with the comet on the far side of the Sun at perihelion.  The comet was intrinsically very faint, and Michael Mattiazzo notes that it was not visible in STEREO imagery post perihelion.  It may not have survived, but it may be worth Southern Hemisphere imagers searching for it.


    2016 R4 (P/Gibbs)
    Alex Gibbs discovered a 19th magnitude comet in images taken with the Mt Lemmon Survey 1.5m reflector on September 10.32. There were pre-discovery images from PanSTARRS on July 18 and August 14, Mount Lemmon on August 28 and Crni Vrh on September 10. [CBET 4325, MPEC 2016-S94, 2016 September 29] The comet was at perihelion at 2.8 au in 2016 July and has a period of around 12 years. 
    2016 S1 (P/PanSTARRS)
    A 19th magnitude comet was discovered in PanSTARRS 1 images taken with the 1.8m Ritchey-Chretien on September 21.57. [CBET 4324, MPEC 2016-S93, 2016 September 29] The comet is at perihelion at 2.4 au in 2017 March and has a period of around 24 years.
    2016 SV (347P/PanSTARRS)
    A 19th magnitude comet was discovered in PanSTARRS 1 images taken with the 1.8m Ritchey-Chretien on September 21.47, with pre-discovery images from June 20 and September 19 that were identified later. Gareth Williams then identified the comet in images from the Catalina Sky Survey from 2009 August and October. It was designated 2009 Q9 for this apparition. [CBET 4323, MPEC 2016-S61, 2016 September 27] The comet was at perihelion at 2.2 au in 2016 September and has a period of 6.9 years.
    2016 T1 (Matheny)
    Rose Matheny discovered an 18th magnitude comet in images taken with the Mt Lemmon Survey 1.5m reflector on October 6.09. [CBET 4328, MPEC 2016-T117, 2016 October 11] The comet is at perihelion at 2.3 au in 2017 February.
    2016 T2 (Matheny)
    Rose Matheny discovered a 19th magnitude comet in images taken with the Mt Lemmon Survey 1.5m reflector on October 10.12. [CBET 4330, MPEC 2016-T135, 2016 October 13] The comet is at perihelion at 1.9 au in 2016 December.
    2016 T3 (PanSTARRS)
    A 20th magnitude comet was discovered in PanSTARRS 1 images taken with the 1.8m Ritchey-Chretien on October 10.38. [CBET 4331, MPEC 2016-U10, 2016 October 18] The comet is at perihelion at 2.6 au in 2017 September.  It has a period of around 1000 years.
    2016 U1 (NEOWISE)
    A 19th magnitude comet was discovered from the NEOWISE satellite on October 21.29, though estimated at some three magnitudes fainter in ground based confirmations. [CBET 4335, MPEC 2016-V16, 2016 November 3] The comet is at perihelion at 0.3 au in 2017 January. It is poorly placed at perihelion.  As is sometimes the case, the magnitude from the discovery observations was much fainter than those made visually once the comet came within range.  Amateur electronic and visual observations in late November and early December put the comet at 12th magnitude, and it has brightened quite rapidly.  It could brighten to 5th magnitude around the time of perihelion, although it is then in solar conjunction.
    A/2016 UX41 [PanSTARRS]
    PanSTARRS discovered a 21st magnitude asteroid in images taken with the 1.8m Ritchey-Chretien on October 27.24. [MPEC 2016-U116, 2016 October 30] The asteroid, classified as an Amor, is at perihelion at 1.3 au in 2016 November and has a period of around 6 years. It has a Jupiter MOID of 0.26 au.
    A/2016 US109 [Mt Lemmon]
    The Mt Lemmon Survey discovered a 20th magnitude asteroid in images taken with the 1.5m reflector on October 19.44. [MPEC 2016-V46, 2016 November 6] The asteroid, classified as a Trans-Neptunian Object, was at perihelion at 1.9 au in 2016 October and has a period of around 200 years. No cometary activity has been detected. The orbit has a Tisserand criterion with respect to Jupiter of 0.23.
    2016 VZ18 (PanSTARRS)
    PanSTARRS discovered a 22nd magnitude asteroid in images taken with the 1.8m Ritchey-Chretien on November 6.44. [MPEC 2016-Y02, 2016 December 16] The asteroid, classified as an Apollo by JPL, is at perihelion at 0.9 au in 2017 March and has a period of around 2700 years. Aphelion is at nearly 400 au. It is a NEO and PHA and has an Earth MOID of 0.020 au and a Jupiter MOID of 0.43 au. No cometary activity has been detected so far, though it is clearly on a cometary type orbit.  It is intrinsically faint, so any cometary activitity is unlikely to bring it within visual range at this return.

    Cometary activity was discovered when it was imaged from the ESA Optical Ground Station in Tenerife in 2017 January.


    A/2016 VY17 [Mt Lemmon]
    The Mt Lemmon Survey discovered an asteroid in images taken with the 1.5m reflector on November 5. The asteroid, classified as a Centaur by JPL, but as an "Other Unusual Object" by the MPC, is at perihelion at 1.7 au in 2017 July and has a retrograde orbit with a period of nearly 40 years. No cometary activity has been detected. The orbit has a Tisserand criterion with respect to Jupiter of -0.85.
    A/2016 WF9 [NEOWISE]
    A 19th magnitude asteroid was discovered from the NEOWISE satellite on November 27.27, though estimated at some two magnitudes fainter in ground based confirmations. [MPEC 2016-W125, 2016 November 30] The asteroid is at perihelion at 1.0 au in 2017 January and has a period of around 6 years. The orbit has a Tisserand criterion with respect to Jupiter of 2.65 and a Jupiter MOID of 0.045 au. No cometary activity has been detected.
    2016 WM48 (Lemmon)
    The Mt Lemmon Survey discovered an asteroid in images taken with the 1.5m reflector on November 30.24. The asteroid, originally classified as a Centaur by JPL, was at perihelion at 1.7 au in 2017 February and has a retrograde orbit with a period of around 23 years. No cometary activity was detected in the month or so immediately after discovery. The orbit has a Tisserand criterion with respect to Jupiter of -0.02.

    Further observations in 2017 May did show cometary activity, and the object was re-designated as a comet.


    2016 X1 (Lemmon)
    An apparently asteroidal object of 20th magnitude was discovered in images taken with the Mt Lemmon Survey 1.5m reflector on December 8.36. There were pre-discovery images from PanSTARRS on November 26. After posting on the NEOCP it was found to show a faint coma and tail. [CBET 4337, MPEC 2016-Y34, 2016 December 21] The comet is at perihelion at 7.6 au in 2019 April and is in a long period orbit.
    A/2016 YB13 [PanSTARRS]
    PanSTARRS discovered a 21st magnitude asteroid in images taken with the 1.8m Ritchey-Chretien on December 23.25. [MPEC 2017-A30, 2017 January 6] The asteroid, currently un-classified by JPL, is at perihelion at 3.2 au in 2017 August and has a retrograde orbit with period of around 13 years. It has a Jupiter MOID of 0.42 au and encountered the planet at 0.43 au in 2002 June.
    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