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 US10 (Catalina): A morning comet visible in binoculars
This comet begins the month in Sculptor at magnitude 9.8. Look for a 5' coma. It should brighten rapidly, moving into Tucana by month's end. The best visibility is late in the month as seen from the southern hemisphere.  FINDER CHART

Latitude Visibility July 4 Visibility July 11 Visibility July 18 Visibility July 25 Visibility August 1 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 1-14
Equator High during morning twilight at ~04:50 High in moonlight at ~04:30 High at ~03:50 Fairly high at ~03:00 Fairly high in the southern sky in moonlight at ~02:00 1-
30o S High in moonlight at ~05:20 High at ~03:20 High at ~03:50 High at ~03:00 Fairly high in the southern sky at ~19:00 1-

C/2014 Q1 (PANSTARRS): An evening comet visible in small telescopes
This comet has been spotted post-perihelion and has brightened to 4th magnitude. It may put on a good show in the evening sky starting on July 15th or so, as seen from the southern hemisphere. It will rise higher each evening and a tail may be visible, but it will also fade, moving into Sextans by month's end.  FINDER CHART
Latitude Visibility July 4 Visibility July 11 Visibility July 18 Visibility July 25 Visibility August 1 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 6-6, 12-13
Equator Not visible Very low in the western sky during evening twilight at ~18:50 Very low in the western sky during evening twilight at ~19:10 Low in the western sky during evening twilight at ~19:10 Low in the western sky during evening twilight at ~19:10 8-
30o S Not visible Not visible Very low in the western sky during evening twilight at ~18:30 Low in the western sky during evening twilight at ~18:30 Low in the western sky during evening twilight at ~18:50 12-

C/2014 Q2 (Lovejoy): A northern hemisphere evening comet visible in small telescopes
This comet begins the month in Ursa Minor at magnitude 8.8. Look for a 7' coma. It should fade by about 0.8 magnitudes, moving into Draco by month's end.  FINDER CHART
Latitude Visibility July 4 Visibility July 11 Visibility July 18 Visibility July 25 Visibility August 1 Nights Visible
55o N High during morning twilight at ~00:00 High during morning twilight at ~00:00 High during morning twilight at ~00:00 High during evening twilight at ~00:00 High during evening twilight at ~22:50 1-
40o N High during evening twilight at ~21:20 High at ~21:40 High at ~21:40 Fairly high at ~00:20 High in moonlight at ~21:10 1-
Equator Low in the northern sky at ~20:00 Fairly high in the northern sky at ~19:40 Fairly high in the northern sky at ~20:10 Fairly high in the northern sky in moonlight at ~19:20 Fairly high during evening twilight at ~19:20 1-
30o S Not visible Not visible Not visible Not visible Not visible  

88P/Howell: A morning comet visible in small telescopes
This comet begins the month in Pisces at magnitude 9.8. Look for a 3' coma. It should fade by about 0.6 magnitudes, moving into Aries by month's end.  FINDER CHART
Latitude Visibility July 4 Visibility July 11 Visibility July 18 Visibility July 25 Visibility August 1 Nights Visible
55o N Low in the eastern sky during morning twilight at ~01:30 Low in the eastern sky during morning twilight at ~01:20 Low in the eastern sky during morning twilight at ~01:10 Low in the eastern sky during morning twilight at ~01:10 Fairly high in the eastern sky during morning twilight at ~02:00 1-
40o N Fairly high in the eastern sky during morning twilight at ~03:10 Fairly high in the eastern sky during morning twilight at ~02:50 Fairly high during morning twilight at ~03:00 Fairly high during morning twilight at ~03:00 High during morning twilight at ~03:30 1-
Equator High during morning twilight at ~04:50 High in moonlight at ~04:40 High at ~04:40 High at ~04:40 High during morning twilight at ~05:00 1-
30o S High during morning twilight at ~05:40 High in moonlight at ~05:30 High at ~05:20 High at ~05:20 High during morning twilight at ~05:20 1-

C/2015 F4 (Jacques): An evening comet visible in a 6-inch (15 cm) telescope
This comet begins the month in Aquila at magnitude 11.5. Look for a 2.5' coma. It should brighten slowly, moving into Cygnus by month's end.  FINDER CHART
Latitude Visibility July 4 Visibility July 11 Visibility July 18 Visibility July 25 Visibility August 1 Nights Visible
55o N Fairly high during morning twilight at ~00:20 High during morning twilight at ~00:10 High during morning twilight at ~00:10 High during morning twilight at ~00:00 High during evening twilight at ~23:20 1-
40o N Low in the eastern sky during evening twilight at ~21:20 High at ~01:00 High at ~00:20 High at ~00:20 High in moonlight at ~23:10 1-
Equator Low in the eastern sky at ~20:30 High at ~01:00 High at ~00:20 High at ~01:20 Fairly high during evening twilight at ~19:20 1-
30o S High in moonlight at ~01:50 High at ~01:00 High at ~00:20 Fairly high in the northern sky at ~01:50 Fairly high in the northern sky in moonlight at ~23:00 1-

22P/Kopff: An evening comet visible in a 12.5-inch (32 cm) telescope
This comet begins the month in Virgo at magnitude 12.9. Look for a 1.5' coma. It should brighten by about 0.7 magnitudes by month's end.  FINDER CHART
Latitude Visibility July 4 Visibility July 11 Visibility July 18 Visibility July 25 Visibility August 1 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 ~22:30 Not visible Not visible Not visible 1-13, 15-16, 18
40o N Fairly high during evening twilight at ~21:20 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 Fairly high in the western sky during evening twilight at ~20:30 1-
Equator High at ~19:30 High at ~19:30 High at ~19:30 High during evening twilight at ~19:20 High during evening twilight at ~19:20 1-
30o S High at ~18:50 High at ~18:50 High in moonlight at ~18:50 High during evening twilight at ~18:40 High at ~19:00 1-

C/2015 G2 (MASTER): A southern hemisphere evening comet visible in very large telescopes
This comet begins the month in Cancer at magnitude 10.2. Look for a 2.5' coma. It should fade rapidly. The best visibility is early in the month as seen from the southern hemisphere.  FINDER CHART
Latitude Visibility July 4 Visibility July 11 Visibility July 18 Visibility July 25 Visibility August 1 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 Not visible Not visible Not visible Not visible Not visible 1-3
30o S Very low in the western sky during evening twilight at ~18:20 Not visible Not visible Not visible Not visible 1-7, 9

29P/Schwassmann-Wachmann: An evening comet visible in very large telescopes
This comet begins the month in Scorpius at magnitude 13.4. Look for a 60" coma. It should remain constant. The best visibility is early in the month as seen from the southern hemisphere.  FINDER CHART
Latitude Visibility July 4 Visibility July 11 Visibility July 18 Visibility July 25 Visibility August 1 Nights Visible
55o N Not visible Not visible Not visible Not visible Not visible  
40o N Low in the southern sky during evening twilight at ~21:10 Low in the southern sky at ~22:10 Low in the southern sky at ~21:40 Low in the southern sky during evening twilight at ~21:10 Low in the southern sky during evening twilight at ~20:50 1-
Equator High at ~20:30 High at ~22:10 High at ~21:40 Fairly high in the western sky at ~01:20 High during evening twilight at ~19:20 1-
30o S High at ~20:10 High at ~22:10 High at ~21:40 Fairly high in the western sky at ~01:50 High at ~19:00 1-

67P/Churyumov-Gerasimenko: A morning comet visible in very large telescopes
This comet begins the month in Taurus at magnitude 13.9. Look for a 40" coma. It should brighten slowly.  FINDER CHART
Latitude Visibility July 4 Visibility July 11 Visibility July 18 Visibility July 25 Visibility August 1 Nights Visible
55o N Not visible Not visible Very low in the eastern sky during morning twilight at ~01:50 Very low in the eastern sky during morning twilight at ~01:50 Low in the eastern sky during morning twilight at ~02:20 18-
40o N Low in the eastern sky during morning twilight at ~03:20 Low in the eastern sky during morning twilight at ~03:00 Low in the eastern sky during morning twilight at ~03:10 Low in the eastern sky during morning twilight at ~03:10 Fairly high in the eastern sky during morning twilight at ~03:40 1-
Equator 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 at ~04:50 Fairly high in the eastern sky during morning twilight at ~04:50 Fairly high in the eastern sky during morning twilight at ~05:00 1-
30o S Fairly high in the eastern sky during morning twilight at ~05:50 Low in the eastern sky during morning twilight at ~05:40 Low in the eastern sky during morning twilight at ~05:30 Low in the eastern sky during morning twilight at ~05:30 Low in the eastern sky during morning twilight at ~05:40 1-

  

Summary Data for This Month's Telescopic Comets


Here's a list of the 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/2014 Q1 (PANSTARRS) Auriga 5.1 1.0' 5.4 1.1' 8.1 1.1' 2015 June 25
C/2014 Q2 (Lovejoy) Ursa Minor 8.8 6.9' 9.1 6.5' 9.6 6.1' 2015 June 24
88P/Howell Pisces 9.8 2.9' 10.0 3.0' 10.3 3.1' 2015 June 28
C/2013 US10 (Catalina) Sculptor 9.8 3.5' 9.0 4.3' 8.1 5.4' 2015 June 28
C/2015 G2 (MASTER) Cancer 10.2 2.5' 11.2 2.1' 12.1 1.9' 2015 June 10
C/2015 F4 (Jacques) Aquila 11.5 2.4' 11.2 2.6' 11.3 2.4' 2015 June 28
19P/Borrelly* Auriga 11.6? 1'? 12.0? 1'? 12.6? 1'? 2015 March 21
22P/Kopff Virgo 12.9 1.3' 12.6 1.3' 12.2 1.2' 2015 June 7
29P/Schwassmann-Wachmann Scorpius 13.4 1.0' 13.4 59" 13.5 58" 2015 June 23
6P/d'Arrest Taurus 13.7 1.0' 14.6 1.0' 15.5 1.0' 2015 June 28
C/2012 F3 (PANSTARRS) Aquila 13.8 31" 13.9 31" 14.0 30" 2015 June 28
67P/Churyumov-Gerasimenko Taurus 13.9 38" 13.7 39" 13.5 40" 2015 June 28
C/2014 W11 (PANSTARRS) Sextans 14.4? 43"? 14.4? 42"? 14.5? 40"? 2015 May 11

*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