Comet Chasing in May

News

• 2013 E2 (Iwamoto) is a new discovery by Masayuki Iwamoto of Japan on March 14. This comet passed perihelion on March 8, and should fade slowly.

• C/2013 A1 (Siding Spring) is a new discovery by Robert McNaught on January 3. This comet will pass very close to Mars on the 19th of October 2014. There is a small possibility that it may impact the planet! It is not currently observable visually.

• C/2012 T5 (Bressi) is in outburst. As first reported by Nirmal Paul on January 24, this comet  brightened significantly to 11th magnitude.

• 273P (was C/2012 V4) is a bright new SWAN discovery that has been linked to the "lost" comet D/1827 M1 (Pons-Gambart).

• 2012 S1 (ISON) is a new discovery that has the potential to be a "Great Comet" in the fall of 2013. It is not currently observable visually except to highly experienced observers using large telescopes from a dark site. 

• 2012 CH17 has apparently disintegrated, as there have been no observations reported since mid September.

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.

Make your own custom charts and predictions for your location and equipment: software for comet observing

Comet Synopses for May

C/2012 F6 (Lemmon): A morning comet visible in binoculars
This comet begins the month in Pisces at magnitude 6.2. Look for a 5' coma. It should fade rapidly, moving into Andromeda by month's end.  FINDER CHART

Latitude	Visibility May 4	Visibility May 11	Visibility May 18	Visibility May 25	Visibility June 1	Nights Visible
55o N	Not visible	Not visible	Very low in the eastern sky during morning twilight at ~01:20	Low in the eastern sky during morning twilight at ~01:20	Low in the eastern sky during morning twilight at ~00:20	1-
40o N	Very low in the eastern sky during morning twilight at ~03:30	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 ~03:10	Fairly high during morning twilight at ~02:40	1-
Equator	Low in the eastern sky during morning twilight at ~04:50	Fairly high in the eastern sky at ~04:40	Fairly high in the eastern sky at ~04:40	Fairly high during morning twilight at ~04:50	Fairly high during morning twilight at ~04:40	1-
30o S	Low 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 ~05:20	Fairly high in the northern sky during morning twilight at ~05:40	Low in the northern sky during morning twilight at ~05:30	1-

C/2011 L4 (PANSTARRS): A northern hemisphere morning comet visible in binoculars
This comet begins the month in Cepheus at magnitude 7.4. Look for a 4' coma. It should fade rapidly, moving into Draco by month's end.  FINDER CHART

Latitude	Visibility May 4	Visibility May 11	Visibility May 18	Visibility May 25	Visibility June 1	Nights Visible
55o N	High at ~00:40	High during morning twilight at ~00:10	High during morning twilight at ~01:00	High during morning twilight at ~00:10	High during evening twilight at ~00:00	1-
40o N	Fairly high at ~02:20	Fairly high at ~02:50	High at ~02:30	High in moonlight at ~02:10	High at ~00:10	1-
Equator	Very low in the northern sky during morning twilight at ~04:50	Very low in the northern sky during morning twilight at ~04:50	Very low in the northern sky during morning twilight at ~04:40	Not visible	Not visible	1-
30o S	Not visible	Not visible	Not visible	Not visible	Not visible

C/2012 L2 (LINEAR): An evening comet visible in an 8-inch (20 cm) telescope
This comet begins the month in Orion at magnitude 10.1. Look for a 2' coma. It should fade slowly.  FINDER CHART

Latitude	Visibility May 4	Visibility May 11	Visibility May 18	Visibility May 25	Visibility June 1	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 ~20:10	Not visible	Not visible	Not visible	Not visible	1-7
Equator	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 ~19:00	Low in the western sky during evening twilight at ~18:50	Very low in the western sky during evening twilight at ~19:00	1-
30o S	Low in the western sky during evening twilight at ~18:40	Low in the western sky during evening twilight at ~18:40	Low in the western sky during evening twilight at ~18:20	Low in the western sky during evening twilight at ~18:10	Low in the western sky during evening twilight at ~18:30	1-

C/2010 S1 (LINEAR): A morning comet visible in a 10-inch (25 cm) telescope
This comet begins the month in Cygnus at magnitude 13.1. Look for a 30" coma. It should brighten slowly.  FINDER CHART

Latitude	Visibility May 4	Visibility May 11	Visibility May 18	Visibility May 25	Visibility June 1	Nights Visible
55o N	Fairly high during morning twilight at ~01:20	Fairly high during morning twilight at ~00:50	High during morning twilight at ~01:00	High during morning twilight at ~01:00	High during morning twilight at ~00:10	1-
40o N	High during morning twilight at ~03:10	High at ~03:00	High at ~02:50	High during morning twilight at ~03:00	High at ~00:50	1-
Equator	High in moonlight at ~04:40	High at ~04:30	High at ~04:30	High in moonlight at ~04:30	High in moonlight at ~04:30	1-
30o S	Fairly high in the northern sky in moonlight at ~05:10	Fairly high in the northern sky at ~05:10	Fairly high in the northern sky at ~05:10	Fairly high in the northern sky in moonlight at ~04:40	Fairly high in the northern sky in moonlight at ~04:30	1-

246P/NEAT: A morning comet visible in a 14-inch (36 cm) telescope
This comet begins the month in Sagittarius at magnitude ~12. Look for a ~4' coma. It should brighten slowly. The best visibility is late in the month as seen from the southern hemisphere.  FINDER CHART

Latitude	Visibility May 4	Visibility May 11	Visibility May 18	Visibility May 25	Visibility June 1	Nights Visible
55o N	Not visible	Not visible	Not visible	Not visible	Not visible
40o N	Low in the southern sky during morning twilight at ~03:20	Low in the southern sky during morning twilight at ~03:00	Low in the southern sky during morning twilight at ~02:50	Fairly high in the southern sky during morning twilight at ~03:10	Low in the southern sky during morning twilight at ~02:40	1-
Equator	High in moonlight at ~04:30	High at ~04:30	High at ~04:10	High in moonlight at ~04:00	High at ~01:00	1-
30o S	High in moonlight at ~05:00	High at ~04:40	High at ~04:10	High in moonlight at ~04:00	High at ~01:10	1-

C/2013 E2 (Iwamoto): A morning comet visible in a 16-inch (41 cm) telescope
This comet begins the month in Pisces at magnitude 11.3. Look for a 3' coma. It should fade by about 0.6 magnitudes by month's end.  FINDER CHART

Latitude	Visibility May 4	Visibility May 11	Visibility May 18	Visibility May 25	Visibility June 1	Nights Visible
55o N	Very low in the eastern sky during morning twilight at ~02:30	Very low in the eastern sky during morning twilight at ~02:10	Not visible	Not visible	Not visible	1-20, 28-
40o N	Low in the eastern sky during morning twilight at ~03:20	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	Fairly high in the eastern sky during morning twilight at ~02:50	1-
Equator	Fairly high during morning twilight at ~04:40	Fairly high at ~04:40	Fairly high at ~04:40	High during morning twilight at ~04:50	High during morning twilight at ~04:40	1-
30o S	Fairly high during morning twilight at ~05:10	Fairly high at ~05:10	Fairly high at ~05:10	Fairly high during morning twilight at ~05:30	Fairly high during morning twilight at ~05:30	1-

C/2006 S3 (LONEOS): An evening comet visible in very large telescopes
This comet begins the month in Virgo at magnitude 11.8. Look for a 4' coma. It should fade slowly.  FINDER CHART

Latitude	Visibility May 4	Visibility May 11	Visibility May 18	Visibility May 25	Visibility June 1	Nights Visible
55o N	Fairly high in the southern sky at ~23:20	Fairly high in the southern sky during evening twilight at ~23:20	Low in the southern sky during morning twilight at ~01:00	Fairly high in the southern sky during evening twilight at ~22:40	Low in the southern sky during evening twilight at ~23:30	1-
40o N	Fairly high at ~23:20	Fairly high at ~22:40	Fairly high in the western sky at ~01:00	Fairly high in moonlight at ~21:30	Fairly high at ~21:30	1-
Equator	High at ~23:20	High at ~22:40	High at ~00:40	High in moonlight at ~21:30	High at ~21:00	1-
30o S	High at ~23:20	High at ~22:40	High at ~00:30	High in moonlight at ~21:40	High at ~21:00	1-

63P/Wild: An evening comet visible in very large telescopes
This comet begins the month in Leo at magnitude 12.3. Look for a 2.5' coma. It should fade by about 0.6 magnitudes, moving into Sextans by month's end.  FINDER CHART

Latitude	Visibility May 4	Visibility May 11	Visibility May 18	Visibility May 25	Visibility June 1	Nights Visible
55o N	Fairly high during evening twilight at ~22:30	Fairly high in the western sky during evening twilight at ~22:50	Fairly high in the western sky during evening twilight at ~22:30	Low in the western sky during evening twilight at ~22:30	Low in the western sky during evening twilight at ~22:50	1-
40o N	High at ~20:50	High at ~21:00	High during evening twilight at ~20:40	High during evening twilight at ~20:50	Fairly high during evening twilight at ~21:20	1-
Equator	High at ~19:30	High at ~19:20	High in moonlight at ~19:50	High in moonlight at ~19:30	High at ~19:20	1-
30o S	High at ~19:10	High at ~19:00	High in moonlight at ~20:10	High in moonlight at ~19:10	High at ~18:40	1-

C/2011 R1 (McNaught): An evening comet visible in very large telescopes
This comet begins the month in Bootes at magnitude 13.0. Look for a 1.5' coma. It should fade by about 0.8 magnitudes by month's end.  FINDER CHART

Latitude	Visibility May 4	Visibility May 11	Visibility May 18	Visibility May 25	Visibility June 1	Nights Visible
55o N	High at ~23:30	High during evening twilight at ~23:40	Fairly high during morning twilight at ~01:10	High during evening twilight at ~23:10	High during evening twilight at ~23:50	1-
40o N	High at ~23:20	High at ~22:40	High at ~01:00	High in moonlight at ~21:50	High at ~21:40	1-
Equator	High at ~23:20	High at ~22:40	High at ~00:40	High in moonlight at ~21:40	High at ~20:50	1-
30o S	High at ~23:20	High at ~22:40	Fairly high at ~00:30	High in moonlight at ~21:40	High at ~20:50	1-

Summary Data for This Month's Telescopic Comets

*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 Astronomical Headlines (IAU) Cometography

Visit Software or the Skyhound observing page.