BAA Comet Section : Comets discovered in 2017

Updated 2017 August 18


  • 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 B5 (354P/LINEAR)
  • 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 GY8 [A/PanSTARRS]
  • 2017 GZ8 [A/Mt Lemmon]
  • 2017 HW3 [A/Mt Lemmon]
  • 2017 HW48 [A/PanSTARRS]
  • 2017 JB6 [A/PanSTARRS]
  • 2017 K1 (PanSTARRS)
  • 2017 K2 (PanSTARRS)
  • 2017 K3 (P/Gasparovic)
  • 2017 K4 (ATLAS)
  • 2017 K5 (PanSTARRS)
  • 2017 K6 (Jacques)
  • 2017 L1 (P/Skiff)
  • 2017 M1 (353P/McNaught)
  • 2017 M2 (355P/LINEAR-NEAT)
  • 2017 M3 (PanSTARRS)
  • 2017 M4 (ATLAS)
  • 2017 M5 (TOTAS)
  • 2017 MB1 [A/Mt Lemmon]
  • 2017 MZ4 [A/PanSTARRS]
  • 2017 MB7 [A/PanSTARRS]
  • 2017 MM7 [A/Mt Lemmon]
  • 2017 NM2 [A/PanSTARRS]
  • 2017 O1
  • 2017 O2 (WISE)
  • 2017 P1 (P/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 was 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 was 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 B5 (354P/LINEAR)
    2010 A2 (P/LINEAR) was recovered as an apparently asteroidal object via CCD images taken by Y. Kim with the 8.1-m "Gemini North" telescope at Mauna Kea on January 26.43. The indicated correction to the prediction by S. Nakano in the ICQ's 2017 Comet Handbook is Delta(T) = +0.16 day. [CBET 4405, MPEC 2017-M38, 2017 June 21]
    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 was 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, was 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 was 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 was 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 after a vote by the Working Group on Small Body Nomenclature.  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 was at perihelion at 5.9 au in 2017 May.  
    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 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.  The comet was at perihelion at 0.5 au in 2017 April.  It was intrinsically faint and having reached 7th magnitude did not survive perihelion.  
    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 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 6.9 au in 2017 November.
    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, was 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 was 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 0.45 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.  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 by 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 GY8 [PanSTARRS]
    PanSTARRS discovered a 22nd magnitude asteroid in images taken with the 1.8m Ritchey-Chretien on April 3.47. The asteroid, classified by JPL as a Centaur, was at perihelion at 8.4 au in 2016 June and has a period of around 140 years. It was placed on the PCCP as P10AMVL.
    A/2017 GZ8 [Mt Lemmon]
    The Mt Lemmon Survey discovered a 19th magnitude asteroid in images taken with the 1.5m reflector on April 3.41. The asteroid is classified as a Centaur by JPL and an "other unusual asteroid" by the MPC. It was at perihelion at 4.0 au in 2017 February and has a period of 21.5 years. The orbit has a Jupiter MOID of 0.03 au and a Tisserand invariant of 2.79. It was placed on the PCCP as YGAC510.
    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 was 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.
    A/2017 HW48 [PanSTARRS]
    PanSTARRS discovered a 21st magnitude asteroid in images taken with the 1.8m Ritchey-Chretien on April 25.54. [MPEC 2017-J11, 2017 May 2] The asteroid, classified as an Amor, was at perihelion at 1.25 au in 2017 July and has a period of 5.2 years. The orbit has a Jupiter MOID of 0.48 au and a Tisserand invariant of 2.97. It is not currently getting close to Jupiter, though it will pass 0.07 au from Mars in 2043 February.
    A/2017 JB6 [PanSTARRS]
    PanSTARRS discovered a 21st magnitude asteroid in images taken with the 1.8m Ritchey-Chretien on April 25. The asteroid, classified by JPL as a Trans-Neptunian Object, was at perihelion at 3.8 au in 2016 October and has a period of around 200 years. It was placed on the PCCP as P10Bfr4.
    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 7.3 au in 2018 March. 
    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 1.8 au in 2022 December. The comet was over 16 au from the Sun at discovery. JPL and the MPC give different absolute magnitudes for the comet, and it is likely that the future brightness evolution is not well determined.  The comet will be a southern hemisphere object when at its brightest, but could be a binocular object for UK observers prior to perihelion.
    2017 K3 (P/Gasparovic)
    Goran Gasparovic, from Zagreb, Croatia, discovered a 19th magnitude comet in images taken by himself and Y Chen with an iTelescope 0.5m f6.8 reflector at Siding Spring on May 22.60. After posting on the PCCP, pre-discovery images from the day before were found in Polonia Observatory images. [CBET 4396, MPEC 2017-L03, 2017 June 1] The comet was near perihelion at 2.3 au and has a period of around 13 years. It is a Jupiter family comet.
    2017 K4 (ATLAS)
    A 17th magnitude comet was discovered in images taken with the 0.5m Schmidt at Haleakala on May 26.51 by the ATLAS (Asteroid Terrestrial-impact Last Alert System) team. [CBET 4397, MPEC 2017-L04, 2017 June 1]. The comet is at perihelion at 2.5 au in 2018 January.
    2017 K5 (PanSTARRS)
    A 22nd magnitude comet was discovered in PanSTARRS 1 images taken with the 1.8m Ritchey-Chretien on May 27.46. [CBET 4398, MPEC 2017-L05, 2017 June 1] The comet is at perihelion at 7.6 au in 2020 March. The error bars on the perihelion distance are 2.1 au and 58 days on the date of perihelion according to JPL.
    2017K6 (Jacques)
    Cristovao Jacques discovered an 18th magnitude comet on images taken with the SONEAR Observatory 0.45m reflector on May 29.31 [CBET 4399, MPEC 2017-L06, 2017 June 1]. The comet has perihelion at around 2.0 au in 2018 January.
    2017 L1 (352P/Skiff)
    H Sato recovered 2000 S1 (P/Skiff) on June 5.81 using the 0.51m i-Telescope at Siding Spring. The indicated correction to the prediction by S. Nakano in the ICQ's 2017 Comet Handbook is Delta(T) = -2.64 days. [CBET 4402, MPEC 2017-L51, 2017 June 6]
    2017 M1 (353P/McNaught)
    K. Sarneczky and R. Konyves-Toth recovered 2009 S2 (P/McNaught) using the 0.60-m Schmidt telescope at the Piszkesteto Station of Konkoly Observatory. The indicated correction to the prediction by S. Nakano in the ICQ's 2017 Comet Handbook (p. H13) is Delta(T) = -0.06 day. [CBET 4404, MPEC 2017-M28, 2017 June 20]
    2017 M2 (355P/LINEAR-NEAT)
    2004 T1 (P/LINEAR-NEAT) was recovered with the 1.0m reflector at the European Space Agency's Optical Ground Station at Tenerife on June 21.17. The indicated correction to the prediction by B. G. Marsden on MPC 89018 is Delta(T) = -0.57 day. The 2011 return was missed because the comet was in conjunction with the sun while near perihelion. [CBET 4406, MPEC 2017-M40, 2017 June 22]
    2017 M3 (PanSTARRS)
    A 21st magnitude comet was discovered in PanSTARRS 1 images taken with the 1.8m Ritchey-Chretien on June 20.29. It was placed on the PCCP as P10BB32. [CBET 4407, MPEC 2017-M44, 2017 June 23] The comet was near perihelion at 4.7 au.
    2017 M4 (ATLAS)
    An 18th magnitude comet was discovered in images taken with the 0.5m Schmidt at Haleakala on June 21.58 by the ATLAS (Asteroid Terrestrial-impact Last Alert System) team. There were PanSTARRS images from June 16.57. [CBET 4408, MPEC 2017-M45, 2017 June 23]. The comet is at perihelion at 3.0 au in 2019 January.
    2017 M5 (TOTAS)
    A 19th magnitude comet was discovered in images taken during the Teide Observatory Tenerife Asteroid Survey with the 1.0m reflector of the ESA Optical Ground Station on June 23.07. [CBET 4410, MPEC 2017-N25, 2017 July 1]. The comet is at perihelion at 6.0 au in 2018 August.
    A/2017 MB1 [Mt Lemmon]
    The Mt Lemmon Survey discovered a 19th magnitude asteroid in images taken with the 1.5m reflector on June 19.41. [MPEC 2017-M48, 2017 June 23] The asteroid is classified as an Apollo by JPL. It is at perihelion at 0.59 au in 2017 September and has a period of 3.7 years. It does not approach closely to Jupiter, but is an NEO and PHA with an Earth MOID of 0.011 au. It made a close approach on July 22.  It can also make close approaches to Venus and Mars.  A team from the University of Ontario noted that the orbit was very close to that of the Alpha Capricornid meteors and that the object might be a weakly active comet. [CBET 4415, 2017 August 2]. Peter Birtwhistle then re-examined his images of the object and noted a possible tail in images taken on July 25. [CBET 4417, 2017 August 3]
    A/2017 MZ4 [PanSTARRS]
    PanSTARRS discovered a 19th magnitude asteroid in images taken with the 1.8m Ritchey-Chretien on June 24.55. [MPEC 2017-M90, 2017 June 29]. The asteroid, classified by JPL as a Trans-Neptunian Object, was at perihelion at 3.2 au in 2017 June and has a period of around 3000 years. It was placed on the PCCP as P10BHYZ.
    A/2017 MB7 [PanSTARRS]
    PanSTARRS discovered a 22nd magnitude asteroid in images taken with the 1.8m Ritchey-Chretien on June 22.31. [MPEC 2017-N23, 2017 July 1]. The asteroid, classified by JPL as a Trans-Neptunian Object, was at perihelion at 4.5 au in 2016 December and has a period of around 3000 years. It was placed on the PCCP as P10BDDW.
    A/2017 MM7 [Mt Lemmon]
    The Mt Lemmon Survey discovered a 20th magnitude asteroid in images taken with the 1.5m reflector on June 26.35. [MPEC 2017-N20, 2017 July 1] The asteroid is classified as an Apollo by JPL. It was at perihelion at 0.084 au in 2017 May and the orbit has an eccentricity of 0.96. There is no evidence for cometary activity, however the perihelion distance is comparable to that of some SOHO comets.
    A/2017 NM2 [PanSTARRS]
    PanSTARRS discovered a 22nd magnitude asteroid in images taken with the 1.8m Ritchey-Chretien on July 6.46. [MPEC 2017-N67, 2017 July 11]. The asteroid, classified by JPL as a Centaur, was at perihelion at 5.5 au in 2017 March and has a retrograde orbit with a period of around 56 years.
    2017 O1
    The All-Sky Automated Survey for Supernovae (ASASSN) discovered a 15th magnitude comet with the "Cassius" 14cm telescope at Cerro Tololo on July 19.32. [CBET 4414, MPEC 2017-O45, 2017 July 24] The comet reaches perihelion at 1.5 au in 2017 October. Even before the discovery announcement JJ Gonzalez had made a visual observation estimating the comet at 10th magnitude. It should become observable from the UK in early August and should be a binocular object over the late summer, autumn and early winter. It will become more conveniently placed in the evening sky by mid September and will still be well placed for observing at the end of the year. It has not yet been named.  Several people have suggested that it must be in outburst, otherwise it should have been detected earlier.
    2017 O2 (P/WISE)
    PanSTARRS discovered a 21st magnitude comet on July 30.54, which appeared on the PCCP as P10Cawe, but was soon linked to 2010 D1 (P/WISE). [CBET 4416, MPEC 2017-P09, 2017 August 3]
    2017 P1 (P/PanSTARRS)
    A 21st magnitude comet was discovered in PanSTARRS 1 images taken with the 1.8m Ritchey-Chretien on August 15.41. There were also pre-discovery images from June 25, July 27 and August 12. [CBET 4420, MPEC 2017-Q12, 2017 August 17] The comet is at perihelion at 5.4 au in 2018 June and has a period of about 22 years. It is a Jupiter-family Comet and has a Jupiter MOID of 0.78 au.
    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