Comet Chasing in September


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 September


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

C/2013 US10 (Catalina): A southern hemisphere evening comet visible in binoculars
This comet begins the month in Triangulum Australe at magnitude 6.4. Look for a 6.5' coma. It should brighten by about 0.6 magnitudes, moving into Centaurus by month's end. The best visibility is late in the month as seen from the southern hemisphere.  FINDER CHART
Latitude Visibility August 29 Visibility September 5 Visibility September 12 Visibility September 19 Visibility September 26 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 Fairly high in the southern sky during evening twilight at ~19:10 Fairly high in the southern sky at ~19:10 Fairly high in the southern sky during evening twilight at ~19:10 Low in the southern sky during evening twilight at ~19:00 Low in the western sky during evening twilight at ~18:50 1-
30o S High in moonlight at ~19:30 High at ~19:10 High at ~19:20 Fairly high during evening twilight at ~19:10 Fairly high during evening twilight at ~19:10 1-

C/2014 Q1 (PANSTARRS): A southern hemisphere evening comet visible in a 6-inch (15 cm) telescope
This comet begins the month in Centaurus at magnitude 10.6. Look for a 2' coma. It should fade rapidly. The best visibility is early in the month as seen from the southern hemisphere.  FINDER CHART
Latitude Visibility August 29 Visibility September 5 Visibility September 12 Visibility September 19 Visibility September 26 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 Low in the western sky during evening twilight at ~18:50 Low in the western sky during evening twilight at ~19:00 Very low in the western sky during evening twilight at ~19:00 Very low in the western sky during evening twilight at ~18:50 Not visible 1-
30o S Fairly high in the western sky during evening twilight at ~18:50 Fairly high in the western sky at ~19:10 Fairly high in the western sky during evening twilight at ~19:10 Fairly high in the western sky during evening twilight at ~19:10 Fairly high in the western sky during evening twilight at ~19:00 1-

C/2014 Q2 (Lovejoy): An evening comet visible in a 6-inch (15 cm) telescope
This comet begins the month in Bootes at magnitude 10.7. Look for a 3.5' coma. It should fade by about 0.7 magnitudes, moving into Corona Borealis by month's end.  FINDER CHART
Latitude Visibility August 29 Visibility September 5 Visibility September 12 Visibility September 19 Visibility September 26 Nights Visible
55o N High during evening twilight at ~21:00 High at ~21:00 High at ~20:40 High at ~20:50 High during evening twilight at ~19:30 1-
40o N High during evening twilight at ~20:00 High at ~20:10 High at ~19:50 High in moonlight at ~19:40 High during evening twilight at ~19:10 1-
Equator Fairly high during evening twilight at ~19:10 Fairly high at ~19:10 Fairly high at ~19:10 Fairly high during evening twilight at ~19:10 Fairly high during evening twilight at ~18:50 1-
30o S Low in the northern sky during evening twilight at ~18:40 Low in the northern sky during evening twilight at ~19:00 Low in the northern sky during evening twilight at ~19:00 Low in the northern sky during evening twilight at ~19:00 Low in the northern sky during evening twilight at ~18:50 1-

C/2015 F4 (Jacques): An evening comet visible in a 6-inch (15 cm) telescope
This comet begins the month in Lyra at magnitude 11.6. Look for a 1.5' coma. It should fade by about 0.8 magnitudes by month's end.  FINDER CHART
Latitude Visibility August 29 Visibility September 5 Visibility September 12 Visibility September 19 Visibility September 26 Nights Visible
55o N High during evening twilight at ~21:20 High at ~21:10 High at ~20:50 High at ~20:50 High during evening twilight at ~19:50 1-
40o N High in moonlight at ~21:10 High at ~20:20 High at ~20:00 High at ~21:40 High in moonlight at ~19:30 1-
Equator High in moonlight at ~20:40 High at ~19:50 High at ~19:30 High in moonlight at ~19:10 High in moonlight at ~19:10 1-
30o S Low in the northern sky in moonlight at ~20:30 Low in the northern sky at ~19:50 Low in the northern sky at ~19:20 Low in the northern sky during evening twilight at ~19:10 Low in the northern sky during evening twilight at ~19:00 1-

88P/Howell: A morning comet visible in a 10-inch (25 cm) telescope
This comet begins the month in Aries at magnitude 11.0. Look for a 3' coma. It should fade slowly.  FINDER CHART
Latitude Visibility August 29 Visibility September 5 Visibility September 12 Visibility September 19 Visibility September 26 Nights Visible
55o N High during morning twilight at ~03:10 High during morning twilight at ~03:00 High at ~03:00 High at ~03:00 High in moonlight at ~02:10 1-
40o N High during morning twilight at ~03:50 High in moonlight at ~03:50 High at ~03:30 High at ~03:00 High during morning twilight at ~04:50 1-
Equator High in moonlight at ~04:00 Fairly high at ~00:20 High at ~03:30 High at ~03:00 High during morning twilight at ~05:00 1-
30o S High in moonlight at ~04:10 Fairly high at ~01:10 High at ~03:30 High at ~03:00 High in moonlight at ~02:20 1-

C/2014 S2 (PANSTARRS): A northern hemisphere morning comet visible in a 10-inch (25 cm) telescope
This comet begins the month in Cassiopeia at magnitude 13.4. Look for a 40" coma. It should brighten by about 0.5 magnitudes, moving into Cepheus by month's end.  FINDER CHART
Latitude Visibility August 29 Visibility September 5 Visibility September 12 Visibility September 19 Visibility September 26 Nights Visible
55o N High during morning twilight at ~02:40 High at ~22:30 High at ~02:50 High at ~03:00 High in moonlight at ~00:00 1-
40o N High in moonlight at ~03:10 High at ~23:20 High at ~03:40 High at ~03:20 High during morning twilight at ~04:50 1-
Equator Fairly high in the northern sky in moonlight at ~04:00 Fairly high in the northern sky in moonlight at ~04:20 Low in the northern sky at ~03:40 Low in the northern sky at ~03:20 Not visible 1-28
30o S Not visible Not visible Not visible Not visible Not visible  

67P/Churyumov-Gerasimenko: A morning comet visible in a 12.5-inch (32 cm) telescope
This comet begins the month in Gemini at magnitude 12.3. Look for a 45" coma. It should fade slowly, moving into Leo by month's end.  FINDER CHART
Latitude Visibility August 29 Visibility September 5 Visibility September 12 Visibility September 19 Visibility September 26 Nights Visible
55o N Fairly high in the eastern sky during morning twilight at ~03:20 Fairly high in the eastern sky during morning twilight at ~03:20 Fairly high in the eastern sky during morning twilight at ~03:20 Fairly high in the eastern sky during morning twilight at ~03:40 Fairly high in the eastern sky during morning twilight at ~04:20 1-
40o N Fairly high in the eastern sky during morning twilight at ~04:10 Fairly high in the eastern sky during morning twilight at ~04:10 Fairly high in the eastern sky during morning twilight at ~04:10 Fairly high in the eastern sky during morning twilight at ~04:10 Fairly high during morning twilight at ~04:50 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 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 ~05:00 1-
30o S Low in the eastern sky during morning twilight at ~05:20 Low in the eastern sky during morning twilight at ~05:10 Low in the eastern sky during morning twilight at ~04:50 Low in the eastern sky during morning twilight at ~04:40 Low in the eastern sky during morning twilight at ~04:50 1-

22P/Kopff: An evening comet visible in a 16-inch (41 cm) telescope
This comet begins the month in Libra at magnitude 11.7. Look for a 2.5' coma. It should brighten slowly. The best visibility is late in the month as seen from the southern hemisphere.  FINDER CHART
Latitude Visibility August 29 Visibility September 5 Visibility September 12 Visibility September 19 Visibility September 26 Nights Visible
55o N Not visible Not visible Not visible Not visible Not visible  
40o N Low in the western sky during evening twilight at ~19:40 Low in the western sky during evening twilight at ~19:50 Low in the western sky during evening twilight at ~19:40 Low in the western sky during evening twilight at ~19:20 Low in the western sky during evening twilight at ~18:50 1-
Equator High during evening twilight at ~19:00 Fairly high at ~19:10 Fairly high at ~19:10 Fairly high during evening twilight at ~19:00 Fairly high during evening twilight at ~18:50 1-
30o S High during evening twilight at ~18:50 Fairly high at ~19:10 Fairly high at ~19:10 Fairly high during evening twilight at ~19:10 Fairly high during evening twilight at ~19:00 1-

141P/Machholz: A morning comet visible in very large telescopes
This comet begins the month in Gemini at magnitude 11.4. Look for a 2' coma. It should fade very rapidly, moving into Leo by month's end.  FINDER CHART
Latitude Visibility August 29 Visibility September 5 Visibility September 12 Visibility September 19 Visibility September 26 Nights Visible
55o N Fairly high in the eastern sky during morning twilight at ~03:20 Low in the eastern sky during morning twilight at ~03:20 Low in the eastern sky during morning twilight at ~03:30 Low in the eastern sky during morning twilight at ~03:40 Fairly high in the eastern sky during morning twilight at ~04:20 1-
40o N Fairly high in the eastern sky during morning twilight at ~04:10 Fairly high in the eastern sky during morning twilight at ~04:10 Fairly high in the eastern sky during morning twilight at ~04:10 Fairly high in the eastern sky during morning twilight at ~04:20 Fairly high in the eastern sky during morning twilight at ~04:50 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 during morning twilight at ~04:40 Fairly high in the eastern sky during morning twilight at ~04:40 Fairly high in the eastern sky during morning twilight at ~05:00 1-
30o S Low in the eastern sky during morning twilight at ~05:20 Low in the eastern sky during morning twilight at ~05:00 Low in the eastern sky during morning twilight at ~04:50 Low in the eastern sky during morning twilight at ~04:40 Not visible 1-25

         

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

September 1st

September 15th

September 30th

Observations as of (UT)
Mag Diam Mag Diam Mag Diam
C/2013 US10 (Catalina) Triangulum Australe 6.4 8.8' 6.2 7.6' 5.9 6.6' 2015 August 29
C/2014 Q1 (PANSTARRS) Centaurus 10.6 2.1' 11.6 1.8' 12.6 1.5' 2015 August 18
C/2014 Q2 (Lovejoy) Bootes 10.7 3.7' 11.0 3.5' 11.3 3.2' 2015 August 14
88P/Howell Aries 11.0 3.1' 11.2 3.3' 11.5 3.3' 2015 August 19
141P/Machholz Gemini 11.4 2.4' 12.9 2.1' 14.9 1.9' 2015 August 28
C/2015 F4 (Jacques) Lyra 11.6 1.4' 12.0 1.2' 12.4 1.1' 2015 August 19
22P/Kopff Libra 11.7 2.7' 11.5 2.6' 11.3 2.6' 2015 August 10
67P/Churyumov-Gerasimenko Gemini 12.3 45" 12.4 45" 12.7 44" 2015 August 19
29P/Schwassmann-Wachmann Ophiuchus 12.4 1.1' 12.5 1.0' 12.6 59" 2015 August 9
C/2015 P3 (SWAN) Hydra 12.6 1.9' 13.8 1.6' 15.0 1.3' 2015 August 18
C/2014 S2 (PANSTARRS) Cassiopeia 13.4 36" 13.1 38" 12.9 40" 2015 August 14
C/2015 G2 (MASTER) Cancer 13.5 1.7' 13.9 1.7' 14.2 1.8' 2015 June 10
C/2012 F3 (PANSTARRS) Sagittarius 13.8 38" 14.0 35" 14.2 33" 2015 July 19
C/2011 KP36 (Spacewatch) Aquarius 13.9 25" 13.9 25" 13.9 24" 2015 July 19
C/2013 X1 (PANSTARRS) Auriga 14.4 29" 14.1 33" 13.6 38" 2015 August 15
C/2014 W2 (PANSTARRS) Auriga 14.6 31" 14.3 33" 14.0 36" 2015 August 26
C/2014 N3 (NEOWISE) Andromeda 14.9 22" 14.9 23" 14.9 23" 2015 August 15

*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