Comet Chasing in November


Comet chasing is the visual observation of telescopic comets.

News


November offers one binocular comet and two comets visible in small telescopes.
  • C/2020 M3 (ATLAS) passed perihelion in late October. On October 25, this comet passed within 0.4 AU of the earth. It is currently predicted to attain maximum brightness of magnitude 7.5 in early November 9.

  • 156P/Russell-LINEAR brightened rapidly and unexpected in October, and has since maintained at least magnitude 12.. This comet will reach perihelion in mid November, when it will also be within 0.5 AU of the earth. 

  • C/2020 S3 (Erasmus) has brightened rapidly. It will reach periehlion on December 12, when It is predicted to reach maximum brightness of magnitude 6.8. 

  • C/2020 P1 (NEOWISE) passed perihelion on October 20.

  • 88P/Howell passed perihelion in late September.

  • 398P/Boattini will reach perihelion in late December. On December 26 this comet will pass within 0.4 AU of the earth, when t is predicted to reach maximum brightness of magnitude 13.5.

  • C/2020 Q1 (Borisov) passed perihelion in mid August. In late September this comet will pass within 0.7 AU of the earth. It is predicted to reach maximum brightness of magnitude 13 in late September.

  • C/2020 F3 (NEOWISE) was a Great Comet that passed perihelion in early July. In late July this comet passed within 0.7 AU of the earth. 

  • C/2020 K8 (Catalina-ATLAS) apparently faded significantly after perihelion on September 14 and appears to no longer be observable.

  • A/2019 U6 (Lemmon). This former asteroid was observed to have a cometary coma in early February, apparently noted by A. Novichonok. It passed perihelion on June 18. 

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

  • C/2019 N1 (ATLAS) will reach perihelion in early December. It is currently predicted to reach a maximum brightness of magnitude 9.7 in early January 2021.

  • 246P/NEAT will next reach perihelion in late February 2021. It is currently predicted to reach maximum brightness of magnitude 13.5 in late June of 2021..

  • 2P/Encke passed perihelion on June 25. In late July this comet passed within 0.6 AU of the earth. 

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

  • 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. It has not been observed since late May and is presumed lost. 

  • 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...

  • 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 continuously.

C/2020 F3 (NEOWISE) on the evening of July 29, in moonlight, from Cloudcroft, New Mexcio.  

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 November


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

C/2020 M3 (ATLAS): A morning comet visible in binoculars
This comet begins the month in Lepus at magnitude 7.6. Look for a 6.5' coma. It should fade slowly, moving into Taurus by month's end.  FINDER CHART
Latitude Visibility October 31 Visibility November 7 Visibility November 14 Visibility November 21 Visibility November 28 Nights Visible
55o N Fairly high in the southern sky in moonlight at ~02:40 Fairly high in moonlight at ~02:30 High at ~01:50 High at ~01:20 High in moonlight at ~01:00 1-
40o N Fairly high in moonlight at ~02:40 Fairly high in the eastern sky at ~22:20 High at ~01:50 High at ~01:20 Fairly high in the western sky during morning twilight at ~05:50 1-
Equator High in moonlight at ~02:40 High at ~23:40 High at ~01:50 High at ~01:20 Fairly high in the western sky during morning twilight at ~04:50 1-
30o S High in moonlight at ~02:40 High at ~00:40 High at ~01:50 High at ~01:20 Fairly high in moonlight at ~01:00 1-

C/2020 S3 (Erasmus): A morning comet visible in small telescopes
This comet begins the month in Sextans at magnitude 10.0. Look for a 4' coma. It should brighten rapidly, moving into Libra by month's end.  FINDER CHART
Latitude Visibility October 31 Visibility November 7 Visibility November 14 Visibility November 21 Visibility November 28 Nights Visible
55o N Fairly high in the southern sky during morning twilight at ~05:30 Low in the southern sky during morning twilight at ~05:30 Very low in the southern sky during morning twilight at ~05:40 Very low in the southern sky during morning twilight at ~06:00 Very low in the southern sky during morning twilight at ~06:40 1-
40o N Fairly high during morning twilight at ~05:10 Fairly high in the eastern sky during morning twilight at ~05:10 Low in the eastern sky during morning twilight at ~05:20 Low in the eastern sky during morning twilight at ~05:30 Very low in the eastern sky during morning twilight at ~06:00 1-
Equator High during morning twilight at ~04:40 Fairly high during morning twilight at ~04:30 Fairly high in the eastern sky at ~04:30 Fairly high in the eastern sky during morning twilight at ~04:30 Low in the eastern sky during morning twilight at ~05:00 1-
30o S Fairly high during morning twilight at ~04:00 Fairly high in the eastern sky during morning twilight at ~03:40 Fairly high in the eastern sky during morning twilight at ~03:30 Low in the eastern sky during morning twilight at ~03:30 Low in the eastern sky during morning twilight at ~03:50 1-

88P/Howell: An evening comet visible in small telescopes
This comet begins the month in Sagittarius at magnitude 8.5. Look for a 7.5' coma. It should fade by about 1.0 magnitudes, moving into Capricornus by month's end.  FINDER CHART
Latitude Visibility October 31 Visibility November 7 Visibility November 14 Visibility November 21 Visibility November 28 Nights Visible
55o N Very low in the southern sky during evening twilight at ~17:40 Very low in the southern sky during evening twilight at ~17:50 Very low in the southern sky during evening twilight at ~17:50 Very low in the southern sky during evening twilight at ~17:40 Low in the southern sky during evening twilight at ~17:20 1-
40o N Low in the southern sky during evening twilight at ~18:10 Low in the southern sky during evening twilight at ~18:20 Low in the southern sky during evening twilight at ~18:20 Fairly high in the southern sky during evening twilight at ~18:10 Fairly high in the southern sky during evening twilight at ~18:00 1-
Equator High during evening twilight at ~18:50 High at ~19:00 Fairly high at ~19:10 High during evening twilight at ~19:00 High during evening twilight at ~19:00 1-
30o S High during evening twilight at ~19:30 Fairly high at ~20:00 Fairly high at ~20:10 Fairly high during evening twilight at ~20:00 Fairly high during evening twilight at ~20:00 1-

C/2019 N1 (ATLAS): A morning comet visible in a 12.5-inch (32 cm) telescope
This comet begins the month in Virgo at magnitude 11.4. Look for a 3' coma. It should brighten slowly.  FINDER CHART
Latitude Visibility October 31 Visibility November 7 Visibility November 14 Visibility November 21 Visibility November 28 Nights Visible
55o N Not visible Very low in the eastern sky during morning twilight at ~05:50 Very low in the eastern sky during morning twilight at ~06:00 Very low in the eastern sky during morning twilight at ~06:10 Very low in the southern sky during morning twilight at ~06:30 1-
40o N Very low in the eastern sky during morning twilight at ~05:30 Very low in the eastern sky during morning twilight at ~05:30 Very low in the eastern sky during morning twilight at ~05:30 Very low in the eastern sky during morning twilight at ~05:30 Low in the eastern sky during morning twilight at ~06:00 1-
Equator Not visible Very low in the eastern sky during morning twilight at ~04:50 Very low in the eastern sky during morning twilight at ~04:40 Low in the eastern sky during morning twilight at ~04:30 Fairly high in the eastern sky during morning twilight at ~05:00 1-
30o S Not visible Not visible Very low in the eastern sky during morning twilight at ~04:00 Very low in the eastern sky during morning twilight at ~03:40 Low in the eastern sky during morning twilight at ~03:50 9-

156P/Russell-LINEAR: An evening comet visible in a 16-inch (41 cm) telescope
This comet begins the month in Aquarius at magnitude 12.0. Look for a 6.5' coma. It should fade slowly, moving into Pisces by month's end.  FINDER CHART
Latitude Visibility October 31 Visibility November 7 Visibility November 14 Visibility November 21 Visibility November 28 Nights Visible
55o N Fairly high in the southern sky in moonlight at ~20:50 Fairly high in the southern sky at ~20:30 Fairly high at ~20:10 Fairly high in the southern sky at ~22:10 High in moonlight at ~19:30 1-
40o N Fairly high in moonlight at ~21:00 High at ~20:30 High at ~20:10 Fairly high at ~23:00 High in moonlight at ~19:30 1-
Equator High in moonlight at ~21:00 High at ~20:30 High at ~20:10 Fairly high in the western sky at ~00:00 High in moonlight at ~19:30 1-
30o S High in moonlight at ~21:00 High at ~20:30 High at ~20:20 High in moonlight at ~20:10 High during evening twilight at ~20:10 1-

398P/Boattini: A morning comet visible in very large telescopes
This comet begins the month in Eridanus at magnitude 14.7. Look for a 1' coma. It should brighten by about 0.9 magnitudes by month's end.  FINDER CHART
Latitude Visibility October 31 Visibility November 7 Visibility November 14 Visibility November 21 Visibility November 28 Nights Visible
55o N Fairly high in the southern sky in moonlight at ~01:30 Fairly high in the southern sky in moonlight at ~01:20 Fairly high in the southern sky at ~00:40 Fairly high in the southern sky at ~00:20 Fairly high in the southern sky in moonlight at ~23:50 1-
40o N Fairly high in moonlight at ~01:30 Fairly high in the eastern sky at ~22:20 Fairly high at ~00:40 Fairly high at ~00:20 Fairly high in moonlight at ~23:50 1-
Equator High in moonlight at ~01:40 High at ~23:40 High at ~00:40 High at ~00:20 High in moonlight at ~23:50 1-
30o S High in moonlight at ~01:40 High at ~00:40 High at ~00:40 High at ~00:40 High in moonlight at ~00:00 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

November 1st

November 15th

November 30th

Observations as of (UT)
Mag Diam Mag Diam Mag Diam
C/2020 M3 (ATLAS) Orion 7.6 6.2' 7.5 6.5' 8.0 5.9' 2020 October 30
88P/Howell Sagittarius 8.5 7.5' 9.0 7.1' 9.5 6.5' 2020 October 13
C/2020 S3 (Erasmus) Sextans 9.9 3.5' 8.8 3.9' 7.4 3.7' 2020 October 30
C/2017 T2 (PANSTARRS) Libra 11.6 4.6' 11.9 4.4' 12.2 4.2' 2020 September 10
156P/Russell-LINEAR Aquarius 12.0 6.6' 12.1 6.2' 12.4 5.5' 2020 October 30
C/2019 N1 (ATLAS) Virgo 12.2 3.1' 12.1 3.3' 11.9 3.4' 2020 August 22
C/2020 Q1 (Borisov) Vulpecula 13.2 43" 14.0 34" 14.8 28" 2020 October 17
C/2020 F3 (NEOWISE) Libra 13.2 2.2' 13.8 2.1' 14.3 2.0' 2020 September 27
C/2020 P1 (NEOWISE) Bootes 13.5 1.5' 15.5 1.1' 17.1 57" 2020 October 28
C/2019 U6 (Lemmon) Hercules 13.5 4.3' 14.0 4.0' 14.4 3.7' 2020 October 22
C/2019 L3 (ATLAS) Cassiopeia 14.3 45" 14.2 46" 14.1 46" 2020 October 22
29P/Schwassmann-Wachmann Aries 14.4 1.3' 14.4 1.3' 14.4 1.3' 2020 October 28
398P/Boattini Eridanus 14.7 53" 14.2 60" 13.8 1.1' 2020 October 25
C/2018 N2 (ASASSN) Draco 14.8 1.7' 14.9 1.7' 15.1 1.7' 2020 October 29
C/2020 J1 (SONEAR) Ara 14.9 20" 14.9 19" 14.9 19" 2020 October 19
C/2020 F5 (MASTER) Pavo 14.9 26" 14.9 25" 15.0 25" 2020 October 13
C/2018 F4 (PANSTARRS) Fornax 15.1 41" 15.2 40" 15.3 38" 2020 October 10
C/2017 K2 (PANSTARRS) Hercules 15.3 36" 15.2 36" 15.1 37" 2020 October 25
C/2017 B3 (LINEAR) Pisces 15.5 47" 15.6 45" 15.8 43" 2020 October 13
*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

Visit Software or the Skyhound observing page