Comet Chasing in July


Comet chasing is the visual observation of telescopic comets.

News


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.

Comet Synopses for July


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

C/2013 X1 (PANSTARRS): An evening comet visible in binoculars
This comet begins the month in Ara at magnitude 7.0. Look for a 8.5' coma. It should fade rapidly, moving into Centaurus by month's end. The best visibility is early in the month as seen from the southern hemisphere.  FINDER CHART
Latitude Visibility July 2 Visibility July 9 Visibility July 16 Visibility July 23 Visibility July 30 Nights Visible
55o N Not visible Not visible Not visible Not visible Not visible  
40o N Not visible Very low in the southern sky during evening twilight at ~21:10 Very low in the southern sky during evening twilight at ~20:40 Very low in the southern sky during evening twilight at ~20:50 Very low in the southern sky during evening twilight at ~20:40 1-
Equator High at ~22:00 Fairly high at ~22:30 High during evening twilight at ~19:20 High at ~19:30 High at ~19:30 1-
30o S High at ~22:00 High at ~22:20 High in moonlight at ~19:00 High at ~19:00 High at ~19:00 1-

C/2015 WZ (PANSTARRS): An evening comet visible in an 8-inch (20 cm) telescope
This comet begins the month in Hercules at magnitude 10.9. Look for a 3' coma. It should fade rapidly, moving into Serpens Caput by month's end.  FINDER CHART
Latitude Visibility July 2 Visibility July 9 Visibility July 16 Visibility July 23 Visibility July 30 Nights Visible
55o N High during morning twilight at ~00:00 High during morning twilight at ~00:00 High during evening twilight at ~23:20 Fairly high during evening twilight at ~23:00 Fairly high in the western sky during evening twilight at ~23:10 1-
40o N High at ~22:10 High at ~22:40 Low in the western sky at ~02:40 High at ~21:20 High at ~21:10 1-
Equator High at ~22:00 High at ~22:30 High in moonlight at ~20:00 High at ~19:40 High at ~19:30 1-
30o S Low in the northern sky at ~22:00 Fairly high in the northern sky at ~22:20 Fairly high in the northern sky in moonlight at ~20:00 Fairly high at ~19:20 High at ~19:00 1-

C/2014 S2 (PANSTARRS): An evening comet visible in an 8-inch (20 cm) telescope
This comet begins the month in Leo at magnitude 11.0. Look for a 4' coma. It should fade by about 0.7 magnitudes by month's end.  FINDER CHART
Latitude Visibility July 2 Visibility July 9 Visibility July 16 Visibility July 23 Visibility July 30 Nights Visible
55o N Low in the western sky during evening twilight at ~23:20 Low in the western sky during evening twilight at ~23:00 Low in the western sky during evening twilight at ~22:20 Very low in the western sky during evening twilight at ~22:00 Not visible 1-
40o N Fairly high in the western sky during evening twilight at ~21:30 Fairly high in the western sky during evening twilight at ~21:20 Fairly high in the western sky during evening twilight at ~20:50 Low in the western sky during evening twilight at ~21:00 Low in the western sky during evening twilight at ~20:50 1-
Equator High at ~19:30 Fairly high during evening twilight at ~19:20 Fairly high during evening twilight at ~19:10 Fairly high in the western sky at ~19:20 Fairly high in the western sky during evening twilight at ~19:20 1-
30o S Fairly high in the northern sky at ~18:40 Fairly high in the northern sky during evening twilight at ~18:40 Fairly high in the northern sky during evening twilight at ~18:30 Fairly high in the western sky during evening twilight at ~18:40 Low in the western sky during evening twilight at ~18:50 1-

9P/Tempel: An evening comet visible in an 8-inch (20 cm) telescope
This comet begins the month in Virgo at magnitude 11.2. Look for a 3.5' coma. It should remain constant. The best visibility is late in the month as seen from the southern hemisphere.  FINDER CHART
Latitude Visibility July 2 Visibility July 9 Visibility July 16 Visibility July 23 Visibility July 30 Nights Visible
55o N Low in the western sky during evening twilight at ~22:40 Very low in the western sky during evening twilight at ~22:20 Not visible Not visible Not visible 1-29
40o N Fairly high in the western sky during evening twilight at ~21:30 Fairly high in the western sky during evening twilight at ~21:20 Fairly high in the western sky during evening twilight at ~20:50 Low in the western sky during evening twilight at ~21:00 Low in the western sky during evening twilight at ~20:50 1-
Equator High at ~19:30 High in moonlight at ~19:30 High during evening twilight at ~19:20 High at ~19:30 High at ~19:30 1-
30o S High at ~18:50 High in moonlight at ~18:40 High during evening twilight at ~18:40 High at ~18:50 High at ~19:00 1-

C/2014 W2 (PANSTARRS): An evening comet visible in a 10-inch (25 cm) telescope
This comet begins the month in Draco at magnitude 12.5. Look for a 2' coma. It should fade slowly, moving into Bootes by month's end.  FINDER CHART
Latitude Visibility July 2 Visibility July 9 Visibility July 16 Visibility July 23 Visibility July 30 Nights Visible
55o N High during morning twilight at ~00:00 High during morning twilight at ~00:00 High during evening twilight at ~23:20 High during evening twilight at ~23:10 High during evening twilight at ~23:20 1-
40o N High at ~21:50 High at ~22:40 Low in the northern sky at ~02:40 High at ~21:20 High at ~21:10 1-
Equator Fairly high at ~20:40 Fairly high in moonlight at ~19:50 High in moonlight at ~19:40 High at ~19:30 High at ~19:30 1-
30o S Very low in the northern sky at ~20:40 Very low in the northern sky in moonlight at ~20:00 Low in the northern sky in moonlight at ~19:30 Low in the northern sky at ~19:00 Fairly high in the northern sky at ~18:50 1-

81P/Wild: An evening comet visible in a 12.5-inch (32 cm) telescope
This comet begins the month in Leo at magnitude 11.2. Look for a 2' coma. It should remain constant.  FINDER CHART
Latitude Visibility July 2 Visibility July 9 Visibility July 16 Visibility July 23 Visibility July 30 Nights Visible
55o N Not visible Not visible Not visible Not visible Not visible  
40o N Very low in the western sky during evening twilight at ~21:00 Very low in the western sky during evening twilight at ~20:50 Very low in the western sky during evening twilight at ~20:30 Very low in the western sky during evening twilight at ~20:30 Very low in the western sky during evening twilight at ~20:20 1-
Equator Fairly high in the western sky during evening twilight at ~19:20 Fairly high in the western sky during evening twilight at ~19:20 Fairly high in the western sky during evening twilight at ~19:10 Low in the western sky during evening twilight at ~19:20 Low in the western sky during evening twilight at ~19:20 1-
30o S Fairly high in the western sky during evening twilight at ~18:40 Fairly high in the western sky during evening twilight at ~18:30 Fairly high in the western sky during evening twilight at ~18:30 Low in the western sky during evening twilight at ~18:40 Low in the western sky during evening twilight at ~18:50 1-

53P/Van Biesbroeck: A morning comet visible in a 12.5-inch (32 cm) telescope
This comet begins the month in Aquarius at magnitude 13.0. Look for a 55" coma. It should remain constant.  FINDER CHART
Latitude Visibility July 2 Visibility July 9 Visibility July 16 Visibility July 23 Visibility July 30 Nights Visible
55o N Low in the southern sky during morning twilight at ~00:20 Fairly high in the southern sky during morning twilight at ~00:20 Fairly high in the southern sky during morning twilight at ~01:50 Fairly high in the southern sky during morning twilight at ~00:50 Fairly high in the southern sky during morning twilight at ~00:20 1-
40o N Fairly high at ~02:20 Fairly high at ~02:00 Fairly high at ~02:40 Low in the eastern sky at ~21:40 Fairly high at ~00:30 1-
Equator High at ~02:30 High at ~02:00 High at ~03:40 Fairly high at ~21:20 High at ~00:30 1-
30o S High at ~02:30 High at ~02:00 High at ~04:30 Fairly high at ~21:10 High at ~00:30 1-

237P/LINEAR: An evening comet visible in a 12.5-inch (32 cm) telescope
This comet begins the month in Virgo at magnitude 13.3. Look for a 40" coma. It should fade slowly. The best visibility is early in the month as seen from the southern hemisphere.  FINDER CHART
Latitude Visibility July 2 Visibility July 9 Visibility July 16 Visibility July 23 Visibility July 30 Nights Visible
55o N Not visible Not visible Not visible Not visible Not visible 1-6
40o N Fairly high in the western sky during evening twilight at ~21:20 Fairly high in the western sky during evening twilight at ~21:10 Fairly high in the western sky during evening twilight at ~20:50 Low in the western sky during evening twilight at ~21:00 Low in the western sky during evening twilight at ~20:50 1-
Equator High at ~19:30 High in moonlight at ~19:30 High during evening twilight at ~19:20 High at ~19:30 High at ~19:30 1-
30o S High at ~18:50 High in moonlight at ~18:50 High during evening twilight at ~18:40 High at ~18:50 High at ~18:50 1-

C/2011 KP36 (Spacewatch): A morning comet visible in very large telescopes
This comet begins the month in Cetus at magnitude 13.9. Look for a 55" coma. It should brighten slowly.  FINDER CHART

Latitude Visibility July 2 Visibility July 9 Visibility July 16 Visibility July 23 Visibility July 30 Nights Visible
55o N Low in the eastern sky during morning twilight at ~01:10 Low in the eastern sky during morning twilight at ~01:00 Fairly high in the eastern sky during morning twilight at ~01:50 Fairly high in the eastern sky during morning twilight at ~01:40 Fairly high in the eastern sky during morning twilight at ~01:10 1-
40o N Fairly high during morning twilight at ~02:40 Fairly high during morning twilight at ~02:40 High at ~02:50 High during morning twilight at ~03:20 High at ~03:00 1-
Equator High at ~04:40 High at ~04:40 High at ~04:40 High in moonlight at ~04:50 High at ~03:40 1-
30o S High at ~05:20 High at ~05:10 High at ~05:00 High in moonlight at ~04:50 High at ~04:10 1-

C/2013 US10 (Catalina): A northern hemisphere morning comet visible in very large telescopes
This comet begins the month in Auriga at magnitude 13.4. Look for a 1.5' coma. It should fade slowly.  FINDER CHART
Latitude Visibility July 2 Visibility July 9 Visibility July 16 Visibility July 23 Visibility July 30 Nights Visible
55o N Low in the northern sky during morning twilight at ~00:20 Low in the northern sky during morning twilight at ~00:20 Low in the northern sky during morning twilight at ~01:00 Fairly high in the northern sky during morning twilight at ~01:20 Fairly high in the northern sky during morning twilight at ~00:50 1-
40o N Low in the northern sky during morning twilight at ~02:50 Low in the northern sky during morning twilight at ~02:50 Low in the northern sky during morning twilight at ~02:50 Fairly high in the eastern sky during morning twilight at ~03:20 Fairly high in the eastern sky at ~03:10 1-
Equator Not visible Not visible Very low in the northern sky during morning twilight at ~05:00 Low in the northern sky during morning twilight at ~05:10 Low in the northern sky during morning twilight at ~04:50 10-
30o S Not visible Not visible Not visible Not visible Not visible  

116P/Wild: An evening comet visible in very large telescopes
This comet begins the month in Libra at magnitude 13.9. Look for a 1.5' coma. It should fade by about 0.9 magnitudes by month's end. The best visibility is early in the month as seen from the southern hemisphere.  FINDER CHART
Latitude Visibility July 2 Visibility July 9 Visibility July 16 Visibility July 23 Visibility July 30 Nights Visible
55o N Not visible Not visible Not visible Not visible Not visible  
40o N Fairly high in the southern sky during evening twilight at ~21:30 Low in the southern sky at ~22:40 Fairly high in the southern sky during evening twilight at ~20:50 Fairly high in the southern sky during evening twilight at ~21:10 Fairly high in the southern sky during evening twilight at ~21:00 1-
Equator High at ~20:30 High at ~22:30 High in moonlight at ~19:30 High at ~19:40 High at ~19:30 1-
30o S High at ~20:30 High at ~22:20 High in moonlight at ~19:30 High at ~19:20 High at ~19:10 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

July 1st

July 15th

July 31st

Observations as of (UT)
Mag Diam Mag Diam Mag Diam
C/2013 X1 (PANSTARRS) Norma 7.4 7.6' 8.0 6.1' 9.0 4.1' 2016 July 5
C/2014 S2 (PANSTARRS) Leo 11.1 3.9' 11.3 3.8' 11.6 3.5' 2016 July 3
C/2015 WZ (PANSTARRS) Corona Borealis 11.1 3.0' 11.5 2.7' 12.4 2.1' 2016 June 6
9P/Tempel Virgo 11.2 3.5' 11.2 3.4' 11.2 3.2' 2016 July 3
81P/Wild Leo 11.2 2.0' 11.2 2.0' 11.3 1.9' 2016 July 2
C/2014 W2 (PANSTARRS) Bootes 12.5 2.0' 12.7 2.0' 12.9 1.9' 2016 July 3
53P/Van Biesbroeck Aquarius 13.0 56" 13.0 58" 13.0 58" 2016 July 3
237P/LINEAR Virgo 13.3 38" 13.4 37" 13.5 34" 2016 July 3
C/2013 US10 (Catalina) Auriga 13.5 1.3' 13.6 1.3' 13.8 1.3' 2016 May 23
C/2011 KP36 (Spacewatch) Cetus 13.9 50" 13.8 51" 13.7 54" 2016 July 3
116P/Wild Libra 14.0 1.3' 14.3 1.2' 14.8 1.1' 2016 July 2
29P/Schwassmann-Wachmann Sagittarius 14.1 53" 14.1 53" 14.1 52" 2016 June 9
77P/Longmore Corvus 14.3 42" 14.4 40" 14.7 37" 2016 July 2
252P/LINEAR Ophiuchus 14.6 1.1' 15.1 60" 15.9 48" 2016 June 4
C/2015 V2 (Johnson) Lynx 15.1 18" 15.0 19" 14.8 19" 2016 June 24

*In solar conjunction and generally not visible

For the latest news and comet observations see the ICQ/CBAT/MPC: Recent Comet Magnitude Estimates page.  The Astronomical Headlines page of the IAU is also a good source of information, particularly for recent discoveries.

For general information about 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