Comet Chasing in May


Comet chasing is the visual observation of telescopic comets.

News


  • C/2016 R2 (PANSTARRS) will reach perihelion in early May. 

  • C/2016 N6 (PANSTARRS) will reach perihelion in mid July. It is predicted to reach maximum brightness of magnitude 12.3 in late June.

  • C/2016 M1 (PANSTARRS) will reach perihelion in early August. It is predicted to reach maximum brightness of magnitude 8 in late July.

  • C/2015 O1 (PANSTARRS) is past perihelion, which occurred in mid February 2018.

  • 62P/Tsuchinshan was recovered in August. It had not been seen since 2004. It brightened significantly and passed perihelion in late November. It has recently been too close to the sun to be observed.

  • 29P/Schwassmann-Wachmann was very active in late August and September. It had the second of two outbursts that occurred within a few days of one another. This second outburst was the brightest since 2010, brightening it up to 12th magnitude. On July 2 in had an outburst that for the first time was caught as the outburst occurred (see https://www.britastro.org/node/10684). Primary outbursts, resulting in a brightening of 0.5 - 1.0 magnitudes, occur roughly every 59 days, typically taking 5-10 days to subside. But up to three subsequent outbursts, such as the one ones recently, may occur 5-10 days afterward, each typically smaller than the last, but sometimes they can be even brighter than the first.  

Read about the first interstellar object to pass through our solar system

 

 

Comet Visibility in the Eyepiece

This page uses code developed for SkyTools 3 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/2016 M1 (PANSTARRS): A morning comet visible in small telescopes
This comet begins the month in Aquila at magnitude 10.5. Look for a 2.5' coma. It should brighten by about 1.0 magnitudes, moving into Sagittarius by month's end. The best visibility is late in the month as seen from the southern hemisphere.  FINDER CHART
Latitude Visibility April 28 Visibility May 5 Visibility May 12 Visibility May 19 Visibility May 26 Nights Visible
55o N Low in the southern sky during morning twilight at ~02:40 Low in the southern sky during morning twilight at ~02:10 Low in the southern sky during morning twilight at ~01:30 Low in the southern sky during morning twilight at ~01:10 Low in the southern sky during morning twilight at ~01:30 1-
40o N Fairly high during morning twilight at ~03:40 Fairly high during morning twilight at ~03:30 Fairly high at ~03:00 Fairly high at ~02:50 Fairly high in the southern sky during morning twilight at ~02:40 1-
Equator High in moonlight at ~04:00 High in moonlight at ~04:40 High at ~04:10 High at ~03:40 High at ~04:10 1-
30o S High in moonlight at ~04:10 High in moonlight at ~05:00 High at ~04:10 High at ~03:40 High at ~04:30 1-

C/2016 N6 (PANSTARRS): An evening comet visible in an 8-inch (20 cm) telescope
This comet begins the month in Lynx at magnitude 12.0. Look for a 1' coma. It should fade slowly.  FINDER CHART
Latitude Visibility April 28 Visibility May 5 Visibility May 12 Visibility May 19 Visibility May 26 Nights Visible
55o N High during evening twilight at ~21:50 High during evening twilight at ~23:00 Fairly high during evening twilight at ~23:20 Fairly high in the northern sky during evening twilight at ~23:30 Fairly high in the northern sky during evening twilight at ~23:10 1-
40o N High during evening twilight at ~20:20 High at ~20:50 High at ~21:00 Fairly high during evening twilight at ~21:00 Fairly high during evening twilight at ~20:50 1-
Equator Fairly high in the northern sky during evening twilight at ~19:00 Fairly high in the northern sky at ~19:10 Fairly high in the northern sky at ~19:10 Fairly high in the northern sky during evening twilight at ~19:10 Fairly high in the northern sky during evening twilight at ~19:00 1-
30o S Not visible Not visible Not visible Not visible Not visible 13-

C/2016 R2 (PANSTARRS): A northern hemisphere evening comet visible in a 10-inch (25 cm) telescope
This comet begins the month in Auriga at magnitude 11.4. Look for a 2' coma. It should fade slowly.  FINDER CHART
Latitude Visibility April 28 Visibility May 5 Visibility May 12 Visibility May 19 Visibility May 26 Nights Visible
55o N Fairly high in the western sky during evening twilight at ~21:30 Fairly high in the northern sky during evening twilight at ~22:40 Low in the northern sky during evening twilight at ~23:10 Low in the northern sky during evening twilight at ~23:20 Low in the northern sky during evening twilight at ~23:00 1-
40o N Fairly high during evening twilight at ~20:10 Fairly high in the western sky during evening twilight at ~20:40 Fairly high in the western sky during evening twilight at ~20:50 Fairly high in the western sky during evening twilight at ~21:00 Fairly high in the northern sky during evening twilight at ~20:50 1-
Equator Low in the northern sky during evening twilight at ~19:00 Low in the northern sky during evening twilight at ~19:10 Low in the northern sky during evening twilight at ~19:10 Low in the northern sky during evening twilight at ~19:00 Low in the northern sky during evening twilight at ~18:50 1-
30o S Not visible Not visible Not visible Not visible Not visible  

C/2015 O1 (PANSTARRS): An evening comet visible in a 16-inch (41 cm) telescope
This comet begins the month in Ursa Major at magnitude 13.6. Look for a 1' coma. It should fade slowly.  FINDER CHART
Latitude Visibility April 28 Visibility May 5 Visibility May 12 Visibility May 19 Visibility May 26 Nights Visible
55o N High in moonlight at ~23:30 High at ~23:30 High during evening twilight at ~23:40 High during morning twilight at ~00:20 High during evening twilight at ~23:20 1-
40o N High in moonlight at ~23:30 High at ~22:50 High at ~22:00 High at ~23:30 High during evening twilight at ~21:10 1-
Equator Fairly high in moonlight at ~23:40 Fairly high at ~22:40 Fairly high at ~22:00 Fairly high at ~22:10 Fairly high in moonlight at ~20:30 1-
30o S Not visible Not visible Not visible Very low in the northern sky at ~21:20 Not visible 8-

37P/Forbes: A morning comet visible in very large telescopes
This comet begins the month in Capricornus at magnitude 13.8. Look for a 5.5' coma. It should brighten slowly, moving into Aquarius by month's end. The best visibility is late in the month as seen from the southern hemisphere.  FINDER CHART
Latitude Visibility April 28 Visibility May 5 Visibility May 12 Visibility May 19 Visibility May 26 Nights Visible
55o N Not visible Not visible Not visible Not visible Not visible  
40o N Low in the eastern sky during morning twilight at ~04:00 Low in the eastern sky during morning twilight at ~03:40 Low in the eastern sky during morning twilight at ~03:10 Low in the eastern sky during morning twilight at ~03:00 Fairly high in the eastern sky during morning twilight at ~03:20 1-
Equator High during morning twilight at ~04:50 High during morning twilight at ~04:50 High at ~04:40 High at ~04:40 High at ~04:30 1-
30o S High during morning twilight at ~05:20 High during morning twilight at ~05:20 High at ~05:10 High at ~05:10 High at ~05:10 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

May 1st

May 15th

May 31st

Observations as of (UT)
Mag Diam Mag Diam Mag Diam
C/2016 M1 (PANSTARRS) Aquila 10.1 2.2' 9.7 2.6' 9.2 3.0' 2018 April 23
C/2016 R2 (PANSTARRS) Auriga 11.6 1.3' 11.7 1.3' 11.8 1.2' 2018 April 20
37P/Forbes Capricornus 12.4 1.6' 12.3 1.7' 12.2 1.9' 2018 April 17
C/2016 N6 (PANSTARRS) Lynx 12.5 60" 12.6 57" 12.7 53" 2018 April 19
C/2015 O1 (PANSTARRS) Ursa Major 13.0 1.6' 13.1 1.5' 13.3 1.4' 2018 April 20
29P/Schwassmann-Wachmann Pisces 15.4 18" 15.3 19" 15.2 20" 2018 April 25

*In solar conjunction and generally not visible

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

Join the Comet Chasing discussion group 

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

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

Links

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