Comet Chasing in June


Comet chasing is the visual observation of telescopic comets.

News


April brought us the busiest month for comets in many years! May offers a naked-eye comet, and six comets visible in small telescopes.
  • A/2019 U6 (Lemmon). This asteroid was observed to have a cometary coma in early February, apparently noted by A. Novichonok. It will reach perihelion on June 18. It is now predicted to reach maximum brightness of magnitude 6.4 in late June, when it will also be best visible.   

  • C/2017 T2 (PANSTARRS) passed perihelion in early May. 

  • C/2020 F8 (SWAN) was discovered on SWAN images on April 9. It passed perihelion on May 26 and  in late May it passed within 0.8 AU of the earth. It is currently a naked-eye object..

  • C/2019 Y4 (ATLAS). This comet had the potential to become a bright naked-eye object near perihelion in late May, but on April 8 it was observed in images to have fragmented. The smaller fragments have separated and begun to fade. The visible coma has faded signifficantly. The remnants like reached maximum brightness in late May.  

  • 2P/Encke will reach perihelion on June 25. In late July this comet will pass within 0.6 AU of the earth. It is predicted to reach maximum brightness of magnitude ~5 in late June. 

  • 58P/Jackson-Neujmion passed periehlion in late May. 

  • C/2020 F3 (NEOWISE) will reach perihelion in early July. In late July this comet will pass within 0.7 AU of the earth. It is currently predicted to reach maximum brightness of magnitude 4 in early July.

  • C/2019 Y1 (ATLAS) passed perihelion in March.

  • 210P/Christensen reached perihelion in early April.

  • C/2018 N2 (ASASSN) passed perihelion in mid November. 

  • C/2018 W2 (Africano)  passed perihelion in early September.

  • 260P/McNaught passed perihelion in early September. 

  • 2I/Borisov (formerly C/2019 Q4) is the first interstellar comet, discovered on August 30, 2019 by G. Borisov. It took until September 10/11 for the interstellar nature of this comet to become readily apparent. On September 24 the IAU officially recognized it as interstellar and assigned a new designation. It will reach perihelion in early December, when it will come within 1.9 AU of the sun and earth. At that time it will be in Hydra. It isn't yet clear how bright it will become, but with comets there is always the possibility that it will brighten enough to be observable visually in large instruments. More here...

  • C/2018 A6 (Gibbs) passed perihelion in mid July.

  • C/2018 F4 (PANSTARRS) is past perihelion, which occurred in early December 2019.

  • 29P/Schwassmann-Wachmann This comet has outbursts, resulting in a brightening of 0.5 - 1.0 magnitudes, which occur roughly every 59 days, typically taking 5-10 days to subside. Up to three subsequent outbursts may occur 5-10 days afterward, each typically smaller than the last, although on some occasions they can be even brighter than the first. These outbursts make 29P one of the most interesting comets to follow, both visually and scientifically. 29P/Schwassmann-Wachmann has a 14.8-year orbital period, and last passed perihelion in early March 2019. It varies in its distance from the Sun from 5.8 AU (at perihelion) to 6.3 AU (at aphelion), which is an unusually small variation for a comet, and remains quite far from the sun at all times. This means that it can be observed more or less contuniously.

C/2019 Y4 (ATLAS) broke up in early April, as seen in these HST images, but the brightest component remains observable

Comet Visibility in the Eyepiece

This page uses code developed for SkyTools to predict the visibility of a comet in the eyepiece.  Predicting how much aperture is required to see a comet is a very complex task.  Have a look for yourself: a comparison of the predictions below (such as "visible in small telescopes") to the magnitude of each comet shows just how poor an indicator the magnitude alone really is.  When you read below that a particular aperture is required to see a comet you can have a reasonable degree of confidence that the comet can in fact be seen in the eyepiece. But always remember, comets are like cats. They both have tails and do what they want, and not always what we expect. This is one of the things that makes comet chasing interesting!

Comet Synopses for May


Explanation of Comet Synopses and charts (read this if you have questions)

C/2019 U6 (Lemmon): An evening comet visible in binoculars
This comet begins the month in Canis Major at magnitude 7.1. Look for a 8.5' coma. It should brighten by about 0.7 magnitudes, moving into Sextans by month's end. The best visibility is late in the month as seen from the southern hemisphere.  FINDER CHART
Latitude Visibility May 30 Visibility June 6 Visibility June 13 Visibility June 20 Visibility June 27 Nights Visible
55o N Not visible Not visible Not visible Not visible Not visible  
40o N Not visible Not visible Not visible Not visible Very low in the western sky during evening twilight at ~20:40 20-
Equator Low in the western sky during evening twilight at ~19:00 Fairly high in the western sky during evening twilight at ~19:00 Fairly high in the western sky during evening twilight at ~19:20 Fairly high in the western sky at ~19:20 Fairly high during evening twilight at ~19:20 1-
30o S Fairly high during evening twilight at ~18:30 Fairly high during evening twilight at ~18:20 Fairly high at ~18:40 Fairly high at ~18:40 High during evening twilight at ~18:30 1-

C/2017 T2 (PANSTARRS): An evening comet visible in binoculars
This comet begins the month in Ursa Major at magnitude 8.5. Look for a 5' coma. It should fade slowly, moving into Canes Venatici by month's end.  FINDER CHART
Latitude Visibility May 30 Visibility June 6 Visibility June 13 Visibility June 20 Visibility June 27 Nights Visible
55o N High during evening twilight at ~23:50 High during evening twilight at ~23:40 High during evening twilight at ~00:00 High during evening twilight at ~00:00 Fairly high during morning twilight at ~00:10 1-
40o N Fairly high in the northern sky at ~01:30 High during evening twilight at ~21:10 High at ~21:40 High at ~21:40 Fairly high in the western sky at ~00:00 1-
Equator Fairly high in the northern sky during evening twilight at ~19:10 Fairly high in the northern sky during evening twilight at ~19:00 Fairly high at ~19:30 Fairly high at ~19:30 High in moonlight at ~19:20 1-
30o S Not visible Not visible Very low in the northern sky during evening twilight at ~18:30 Low in the northern sky at ~18:40 Low in the northern sky during evening twilight at ~18:30 9-

C/2020 F8 (SWAN): A far-northern evening comet visible in small telescopes
This comet begins the month in Auriga at magnitude 7.4. Look for a 3' coma. It should fade rapidly.  FINDER CHART
Latitude Visibility May 30 Visibility June 6 Visibility June 13 Visibility June 20 Visibility June 27 Nights Visible
55o N Low in the northern sky during evening twilight at ~23:40 Very low in the northern sky during evening twilight at ~23:10 Very low in the northern sky during evening twilight at ~23:00 Not visible Not visible 1-18
40o N Very low in the northern sky during evening twilight at ~20:50 Very low in the northern sky during evening twilight at ~20:40 Not visible Not visible Not visible 1-16
Equator Not visible Not visible Not visible Not visible Not visible  
30o S Not visible Not visible Not visible Not visible Not visible  

2P/Encke: An evening comet visible in a 6-inch (15 cm) telescope
This comet begins the month in Taurus, likely near magnitude 10.3. As the month begins we don't yet have any visual obserations to report. It should brighten rapidly, moving into Cancer by month's end.  FINDER CHART
Latitude Visibility May 30 Visibility June 6 Visibility June 13 Visibility June 20 Visibility June 27 Nights Visible
55o N Not visible Not visible Not visible Not visible Not visible  
40o N Not visible Not visible Not visible Not visible Not visible 25-
Equator Not visible Not visible Not visible Not visible Very low in the western sky during evening twilight at ~18:50 21-
30o S Not visible Not visible Not visible Not visible Very low in the western sky during evening twilight at ~18:00 22-

58P/Jackson-Neujmin: A morning comet visible in a 6-inch (15 cm) telescope
This comet begins the month in Pisces at magnitude 10.2. Look for a 2.5' coma. It should fade slowly, moving into Taurus by month's end. The best visibility is early in the month as seen from the southern hemisphere.  FINDER CHART
Latitude Visibility May 30 Visibility June 6 Visibility June 13 Visibility June 20 Visibility June 27 Nights Visible
55o N Not visible Not visible Not visible Not visible Not visible  
40o N Very low in the eastern sky during morning twilight at ~03:30 Very low in the eastern sky during morning twilight at ~03:30 Very low in the eastern sky during morning twilight at ~03:20 Very low in the eastern sky during morning twilight at ~03:10 Very low in the eastern sky during morning twilight at ~03:10 1-
Equator Low in the eastern sky during morning twilight at ~04:40 Fairly high in the eastern sky during morning twilight at ~05:00 Fairly high in the eastern sky during morning twilight at ~04:50 Fairly high in the eastern sky during morning twilight at ~04:40 Fairly high in the eastern sky during morning twilight at ~04:50 1-
30o S Fairly high in the eastern sky during morning twilight at ~05:20 Fairly high in the eastern sky during morning twilight at ~05:40 Fairly high in the eastern sky during morning twilight at ~05:40 Fairly high in the eastern sky during morning twilight at ~05:30 Fairly high in the eastern sky at ~05:30 1-

C/2019 Y1 (ATLAS): An evening comet visible in a 6-inch (15 cm) telescope
This comet begins the month in Ursa Major at magnitude 10.1. Look for a 3.5' coma. It should fade rapidly, moving into Coma Berenices by month's end.  FINDER CHART
Latitude Visibility May 30 Visibility June 6 Visibility June 13 Visibility June 20 Visibility June 27 Nights Visible
55o N High during evening twilight at ~23:50 High during evening twilight at ~23:30 Fairly high during evening twilight at ~23:50 Fairly high in the western sky during evening twilight at ~23:50 Fairly high in the western sky during evening twilight at ~23:40 1-
40o N Fairly high in the western sky at ~01:30 High during evening twilight at ~21:10 High at ~21:40 High at ~21:40 High during evening twilight at ~21:20 1-
Equator High in moonlight at ~19:20 High during evening twilight at ~19:00 High at ~19:30 High at ~19:30 High during evening twilight at ~19:20 1-
30o S Low in the northern sky in moonlight at ~18:50 Low in the northern sky in moonlight at ~19:00 Fairly high in the northern sky at ~18:40 Fairly high in the northern sky at ~18:40 Fairly high during evening twilight at ~18:30 1-

C/2020 F3 (NEOWISE): An evening comet visible in a 10-inch (25 cm) telescope
This comet begins the month in Orion at magnitude 7.9. Look for a 5' coma. It should brighten rapidly, moving into Taurus by month's end. The best visibility is early in the month as seen from the southern hemisphere.  FINDER CHART
Latitude Visibility May 30 Visibility June 6 Visibility June 13 Visibility June 20 Visibility June 27 Nights Visible
55o N Not visible Not visible Not visible Not visible Not visible  
40o N Not visible Not visible Not visible Not visible Not visible 30-
Equator Very low in the western sky during evening twilight at ~19:00 Very low in the western sky during evening twilight at ~18:40 Not visible Not visible Not visible 1-8, 29-
30o S Low in the western sky during evening twilight at ~18:20 Low in the western sky during evening twilight at ~18:10 Very low in the western sky during evening twilight at ~17:50 Not visible Not visible 1-16

C/2018 A6 (Gibbs): A morning comet visible in a 10-inch (25 cm) telescope
This comet begins the month in Sculptor at magnitude 13.5. Look for a 15" coma. It should remain constant. The best visibility is mid-month as seen from the southern hemisphere.  FINDER CHART
Latitude Visibility May 30 Visibility June 6 Visibility June 13 Visibility June 20 Visibility June 27 Nights Visible
55o N Not visible Not visible Not visible Not visible Not visible  
40o N Not visible Not visible Very low in the southern sky during morning twilight at ~03:20 Very low in the southern sky during morning twilight at ~03:10 Low in the southern sky during morning twilight at ~03:00 8-
Equator Fairly high during morning twilight at ~04:40 High during morning twilight at ~04:50 High during morning twilight at ~04:40 High at ~04:40 High at ~04:40 1-
30o S High at ~05:20 High during morning twilight at ~05:30 High in moonlight at ~05:30 High at ~05:20 High at ~05:20 1-

C/2018 F4 (PANSTARRS): A southern hemisphere morning comet visible in an 18-inch (46 cm) telescope
This comet begins the month in Fornax at magnitude 14.0. Look for a 45" coma. It should remain constant. The best visibility is late in the month as seen from the southern hemisphere.  FINDER CHART
Latitude Visibility May 30 Visibility June 6 Visibility June 13 Visibility June 20 Visibility June 27 Nights Visible
55o N Not visible Not visible Not visible Not visible Not visible  
40o N Not visible Not visible Not visible Not visible Not visible  
Equator Very low in the eastern sky during morning twilight at ~05:00 Low in the eastern sky during morning twilight at ~05:10 Low in the eastern sky during morning twilight at ~05:00 Low in the eastern sky during morning twilight at ~04:50 Fairly high in the eastern sky during morning twilight at ~04:50 1-
30o S Fairly high in the eastern sky during morning twilight at ~05:20 Fairly high during morning twilight at ~05:40 Fairly high during morning twilight at ~05:30 High at ~05:30 High at ~05:30 1-

C/2019 Y4 (ATLAS): A southern hemisphere morning comet visible in very large telescopes
This comet begins the month in Taurus at magnitude 7.0. Look for a 4' coma. It should fade rapidly, moving into Orion by month's end. The best visibility is early in the month as seen from the southern hemisphere.  FINDER CHART
Latitude Visibility May 30 Visibility June 6 Visibility June 13 Visibility June 20 Visibility June 27 Nights Visible
55o N Not visible Not visible Not visible Not visible Not visible  
40o N Not visible Not visible Not visible Not visible Not visible  
Equator Very low in the eastern sky during morning twilight at ~05:20 Very low in the eastern sky during morning twilight at ~05:20 Not visible Not visible Not visible 1-6
30o S Very low in the eastern sky during morning twilight at ~06:10 Very low in the eastern sky during morning twilight at ~06:00 Very low in the eastern sky during morning twilight at ~05:50 Very low in the eastern sky during morning twilight at ~05:50 Very low in the eastern sky during morning twilight at ~05:50 1-

C/2019 N1 (ATLAS): A northern hemisphere evening comet visible in very large telescopes
This comet begins the month in Draco at magnitude 13.7. Look for a 2.5' coma. It should brighten slowly, moving into Ursa Major by month's end.  FINDER CHART
Latitude Visibility May 30 Visibility June 6 Visibility June 13 Visibility June 20 Visibility June 27 Nights Visible
55o N High during evening twilight at ~23:50 High during evening twilight at ~23:50 High during evening twilight at ~00:00 High during evening twilight at ~00:00 High during morning twilight at ~00:10 1-
40o N Fairly high at ~01:30 High during evening twilight at ~21:20 High at ~21:40 High at ~21:40 Fairly high in the northern sky at ~00:00 1-
Equator Low in the northern sky in moonlight at ~19:50 Fairly high in the northern sky during evening twilight at ~19:00 Fairly high in the northern sky at ~19:30 Fairly high in the northern sky at ~19:30 Fairly high in the northern sky during evening twilight at ~19:20 1-
30o S Not visible Not visible Not visible Not visible Not visible  

C/2018 N2 (ASASSN): A northern hemisphere morning comet visible in very large telescopes
This comet begins the month in Cassiopeia at magnitude 13.5. Look for a 1' coma. It should fade slowly, moving into Cepheus by month's end.  FINDER CHART
Latitude Visibility May 30 Visibility June 6 Visibility June 13 Visibility June 20 Visibility June 27 Nights Visible
55o N Fairly high during evening twilight at ~00:00 High during morning twilight at ~00:10 High during morning twilight at ~00:00 High during morning twilight at ~00:00 High during morning twilight at ~00:10 1-
40o N Fairly high at ~02:30 Fairly high during morning twilight at ~02:50 Fairly high at ~01:00 Fairly high at ~02:20 Fairly high at ~02:20 1-
Equator Very low in the northern sky during morning twilight at ~04:50 Very low in the northern sky during morning twilight at ~05:00 Very low in the northern sky during morning twilight at ~04:50 Very low in the northern sky during morning twilight at ~04:50 Very low in the northern sky during morning twilight at ~05:00 1-29
30o S Not visible Not visible Not visible Not visible Not visible  

88P/Howell: An evening comet visible in very large telescopes
This comet begins the month in Virgo at magnitude 14.5. Look for a 40" coma. It should brighten by about 0.5 magnitudes by month's end.  FINDER CHART
Latitude Visibility May 30 Visibility June 6 Visibility June 13 Visibility June 20 Visibility June 27 Nights Visible
55o N Fairly high in the western sky during evening twilight at ~23:10 Low in the western sky during evening twilight at ~22:50 Low in the western sky during evening twilight at ~23:10 Low in the western sky during evening twilight at ~23:00 Low in the western sky during evening twilight at ~22:40 1-
40o N High during evening twilight at ~21:10 High during evening twilight at ~21:00 Fairly high during evening twilight at ~21:30 Fairly high during evening twilight at ~21:30 Fairly high during evening twilight at ~21:20 1-
Equator Low in the western sky at ~01:00 High during evening twilight at ~19:00 High at ~19:30 High at ~19:30 High during evening twilight at ~19:20 1-
30o S Low in the western sky at ~00:40 High in moonlight at ~20:20 High at ~19:10 High at ~19:00 High in moonlight at ~18:40 1-

Summary Data for This Month's Telescopic Comets


Comets brighter than 15th magnitude.  This table is updated as necessary. The last column indicates the date of the last observation used to compute these values.  The constellation listed is where the comet was on the first of the month.
Comet Constellation

June 1st

June 15th

June 30th

Observations as of (UT)
Mag Diam Mag Diam Mag Diam
C/2019 Y4 (ATLAS) Taurus 7.0 4.5' 11.0 3.0' 13.7 2.4' 2020 May 18
C/2019 U6 (Lemmon) Canis Major 7.1 6.7' 6.5 8.1' 6.4 8.8' 2020 May 30
C/2020 F8 (SWAN) Auriga 7.4 3.2' 9.7 2.2' 11.7 1.8' 2020 May 26
C/2020 F3 (NEOWISE) Orion 7.9 5.1' 6.4 5.3' 3.7 6.4' 2020 May 30
C/2017 T2 (PANSTARRS) Ursa Major 8.5 5.0' 8.7 4.9' 9.0 4.7' 2020 May 28
C/2019 Y1 (ATLAS) Ursa Major 10.1 3.8' 10.9 3.2' 11.8 2.6' 2020 May 28
2P/Encke Taurus 10.? 1.4'? 6.8? 1.6'? 4.7? 2.2'? 2017 April 28
58P/Jackson-Neujmin Pisces 10.2 2.5' 10.3 2.5' 10.4 2.5' 2020 May 31
29P/Schwassmann-Wachmann Aries 13.0 60" 13.0 1.0' 12.9 1.0' 2020 March 9
210P/Christensen Cancer 13.5 1.1' 14.5 56" 15.5 48" 2020 May 18
C/2018 N2 (ASASSN) Cassiopeia 13.5 1.1' 13.6 1.1' 13.7 1.1' 2020 May 29
C/2018 F4 (PANSTARRS) Fornax 14.0 43" 14.0 43" 14.0 44" 2020 April 24
C/2019 N1 (ATLAS) Draco 14.4 46" 14.1 47" 13.9 47" 2020 May 18
88P/Howell Virgo 14.5 43" 14.3 41" 14.0 40" 2020 May 18
246P/NEAT Coma Berenices 14.7 31" 14.7 30" 14.8 28" 2020 May 17
C/2020 F5 (MASTER) Octans 15.1 21" 15.1 22" 15.0 22" 2020 April 22
C/2017 K2 (PANSTARRS) Draco 15.3 42" 15.2 43" 15.1 43" 2020 May 24
C/2020 H2 (Pruyne) Ursa Major 15.6 29" 16.9 21" 18.1 17" 2020 May 18
C/2016 M1 (PANSTARRS) Lepus 15.7 1.7' 15.8 1.7' 15.9 1.6' 2020 March 28
*In solar conjunction and generally not visible

For information about specific comets see Gary W. Kronk's Cometography 

Further reading: see Comet Chasing, Sky & Telescope, April 2005, pg. 83.

Make your own custom charts for your location and telescope/binoculars: software for visual comet observing

New: software for comet imaging
 

Links

Skyhound's Guide to Comets
Skyhound's Guide to Finding Comets
BAA Comet Section
Weekly Information About Bright Comets
Cometography

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