[size=+2]Comet Chasing in January
Comet chasing is the visual observation of telescopic comets. [size=+1]News
2011 W3 (Lovejoy) has unexpectedly survived perihelion! This comet is visible just before dawn from the southern hemisphere. P/2006 T1 (Levy) is very faint--possibly fainter than 20th magnitude. Various web sites and most software (online or otherwise--including Google Sky) is showing this comet as 11th magnitude. There are web sites predicting it will be 7th magnitude in January, which is highly doubtful. In fact this comet has not been observed since 2006 and the orbital data and magnitude parameters are not up to date. The creators of these web sites and software do not monitor actual observations and the result is unreliable information. In fact these sources also still show 2010 X1 (Elenin) which disintegrated over a month ago! What a huge disservice they are doing. I urge readers to complain about it to them. 2010 X1 (Elenin) has disintegrated. It faded dramatically after a solar flare on August 20. Images at the end of August revealed a spreading, more diffuse coma. The remnants of this comet can be observed visually, but it is a difficult observation requiring a dark site and considerable expertise in spotting diffuse objects. 2011 Q4 (SWAN) is a new discovery of September 5 via SWAN, apparently independently by Vladimir Bezugly and Rob Matson. See below for details.
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 [size=+1]Comet Synopses for January
Charts look poor or grainy? Read this. C/2011 W3 (Lovejoy): A morning comet visible in binoculars
[size=-1]This comet begins the month in Ara with a coma magnitude of 5. Look for at least a 5o[size=-1] tail, which is this comet's most visible feature. It should fade rapidly, moving into Caelum by month's end. The best visibility is early in the month as seen from the southern hemisphere. FINDER CHART Latitude | Visibility December 31 | Visibility January 7 | Visibility January 14 | Visibility January 21 | Visibility January 28 | Nights Visible | 55[size=-2]o N | Not visible | Not visible | Not visible | Not visible | Not visible | | 40[size=-2]o N | Not visible | Not visible | Not visible | Not visible | Very low in the southern sky in moonlight at ~20:10 | 24- | Equator | Very low in the southern sky during morning twilight at ~05:00 | Not visible | Low in the southern sky at ~21:00 | Fairly high at ~20:40 | High in moonlight at ~20:00 | 1-5, 9- | 30[size=-2]o S | Fairly high in the southern sky during morning twilight at ~03:30 | Fairly high in the southern sky in moonlight at ~01:20 | High at ~21:00 | High at ~20:50 | High at ~21:50 | 1- | C/2009 P1 (Garradd): A morning comet visible in binoculars
[size=-1]This comet begins the month in Hercules at magnitude 6.7. Look for a 5" coma. It should brighten slowly. FINDER CHART Latitude | Visibility December 31 | Visibility January 7 | Visibility January 14 | Visibility January 21 | Visibility January 28 | Nights Visible | 55[size=-2]o N | Fairly high during morning twilight at ~06:10 | High during morning twilight at ~06:30 | High during morning twilight at ~06:10 | High at ~06:00 | High at ~05:50 | 1- | 40[size=-2]o N | Fairly high in the eastern sky during morning twilight at ~05:50 | Fairly high during morning twilight at ~06:00 | High during morning twilight at ~05:50 | High at ~05:40 | High at ~05:40 | 1- | Equator | Not visible | Low in the eastern sky during morning twilight at ~05:10 | Low in the eastern sky during morning twilight at ~05:10 | Fairly high in the eastern sky during morning twilight at ~05:00 | Fairly high in the eastern sky during morning twilight at ~05:00 | 1- | 30[size=-2]o S | Not visible | Not visible | Not visible | Not visible | Not visible | 1-20, 25- | 29P/Schwassmann-Wachmann: A morning comet visible in a 12.5-inch telescope
[size=-1]This comet begins the month in Corvus, perhaps as bright as magnitude 10.2. Look for a 7' coma. This comet was apparently caught in one of its frequent outbursts near the end of December. It is typically much fainter. FINDER CHART Latitude | Visibility December 31 | Visibility January 7 | Visibility January 14 | Visibility January 21 | Visibility January 28 | Nights Visible | 55[size=-2]o N | Fairly high in the southern sky at ~05:50 | Fairly high in the southern sky in moonlight at ~05:10 | Fairly high in the southern sky in moonlight at ~04:50 | Fairly high in the southern sky at ~04:40 | Fairly high in the southern sky at ~04:10 | 1- | 40[size=-2]o N | Fairly high at ~05:40 | Fairly high in moonlight at ~04:50 | Fairly high in moonlight at ~04:40 | Fairly high at ~04:40 | Fairly high at ~04:10 | 1- | Equator | High at ~04:40 | High during morning twilight at ~05:10 | High in moonlight at ~04:40 | High at ~04:30 | High at ~04:10 | 1- | 30[size=-2]o S | High during morning twilight at ~03:30 | High during morning twilight at ~03:40 | High during morning twilight at ~03:50 | High at ~03:40 | High at ~03:50 | 1- | 78P/Gehrels: An evening comet visible in a 12.5-inch telescope
[size=-1]This comet begins the month in Pisces at magnitude 10.6. Look for a 4.5' coma. It should fade slowly. FINDER CHART Latitude | Visibility December 31 | Visibility January 7 | Visibility January 14 | Visibility January 21 | Visibility January 28 | Nights Visible | 55[size=-2]o N | Fairly high during evening twilight at ~18:00 | Fairly high in moonlight at ~18:10 | Fairly high at ~18:20 | Fairly high at ~18:30 | Fairly high during evening twilight at ~18:30 | 1- | 40[size=-2]o N | High during evening twilight at ~18:20 | High during evening twilight at ~18:20 | High at ~18:40 | High at ~18:40 | High during evening twilight at ~18:50 | 1- | Equator | High during evening twilight at ~19:20 | High during evening twilight at ~19:20 | High at ~19:30 | High at ~19:30 | High during evening twilight at ~19:30 | 1- | 30[size=-2]o S | High during evening twilight at ~20:30 | Fairly high during evening twilight at ~20:20 | Fairly high during evening twilight at ~20:30 | Fairly high during evening twilight at ~20:30 | Fairly high in the western sky during evening twilight at ~20:20 | 1- | C/2010 S1 (LINEAR): A northern hemisphere evening comet visible in a 12.5-inch telescope
[size=-1]This comet begins the month in Lacerta at magnitude 13.6. Look for a 30" coma. It should remain constant, moving into Andromeda by month's end. FINDER CHART Latitude | Visibility December 31 | Visibility January 7 | Visibility January 14 | Visibility January 21 | Visibility January 28 | Nights Visible | 55[size=-2]o N | High in moonlight at ~18:00 | High during evening twilight at ~18:00 | High at ~18:20 | High at ~18:30 | High during evening twilight at ~18:30 | 1- | 40[size=-2]o N | High during evening twilight at ~18:20 | High during evening twilight at ~18:20 | High at ~18:30 | High at ~18:40 | High during evening twilight at ~18:40 | 1- | Equator | Fairly high in the northern sky during evening twilight at ~19:10 | Fairly high in the northern sky during evening twilight at ~19:10 | Low in the northern sky during evening twilight at ~19:20 | Low in the northern sky during evening twilight at ~19:20 | Low in the northern sky during evening twilight at ~19:10 | 1- | 30[size=-2]o S | Not visible | Not visible | Not visible | Not visible | Not visible | | C/2010 G2 (Hill): An evening comet visible in a 14-inch telescope
[size=-1]This comet begins the month in Cetus at magnitude 10.3. Look for a 4.5' coma. It should fade by about 1.1 magnitudes, moving into Eridanus by month's end. FINDER CHART Latitude | Visibility December 31 | Visibility January 7 | Visibility January 14 | Visibility January 21 | Visibility January 28 | Nights Visible | 55[size=-2]o N | Fairly high in moonlight at ~20:20 | Fairly high in moonlight at ~19:50 | Fairly high at ~19:20 | Fairly high at ~18:50 | Fairly high in moonlight at ~18:40 | 1- | 40[size=-2]o N | High in moonlight at ~20:20 | High in moonlight at ~19:50 | High at ~19:20 | High at ~19:00 | High in moonlight at ~18:50 | 1- | Equator | High at ~23:40 | High in moonlight at ~19:50 | High at ~19:40 | High at ~19:30 | High in moonlight at ~19:30 | 1- | 30[size=-2]o S | Fairly high at ~23:20 | High during evening twilight at ~20:30 | High at ~20:40 | High during evening twilight at ~20:30 | High during evening twilight at ~20:30 | 1- | 21P/Giacobini-Zinner: A northern hemisphere evening comet visible in very large telescopes
[size=-1]This comet begins the month in Aquila at magnitude 8.9. Look for a 10' coma. It should brighten by about 0.9 magnitudes, moving into Aquarius by month's end. FINDER CHART Latitude | Visibility December 31 | Visibility January 7 | Visibility January 14 | Visibility January 21 | Visibility January 28 | Nights Visible | 55[size=-2]o N | Low in the western sky during evening twilight at ~17:40 | Low in the western sky during evening twilight at ~17:30 | Very low in the western sky during evening twilight at ~17:50 | Very low in the western sky during evening twilight at ~18:00 | Very low in the western sky during evening twilight at ~18:10 | 1- | 40[size=-2]o N | Low in the western sky during evening twilight at ~18:10 | Low in the western sky during evening twilight at ~18:00 | Low in the western sky during evening twilight at ~18:20 | Very low in the western sky during evening twilight at ~18:30 | Very low in the western sky during evening twilight at ~18:30 | 1- | Equator | Very 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 ~19:10 | Very low in the western sky during evening twilight at ~19:10 | Very low in the western sky during evening twilight at ~19:10 | 1- | 30[size=-2]o S | Not visible | Not visible | Not visible | Not visible | Not visible | | C/2011 Q4 (SWAN): A morning comet visible in very large telescopes
[size=-1]This comet begins the month in Bootes at magnitude 11.6. Look for a 3.5' coma. It should fade slowly, moving into Canes Venatici by month's end. FINDER CHART Latitude | Visibility December 31 | Visibility January 7 | Visibility January 14 | Visibility January 21 | Visibility January 28 | Nights Visible | 55[size=-2]o N | High at ~06:00 | High in moonlight at ~05:50 | High during morning twilight at ~06:10 | High at ~05:40 | High at ~05:10 | 1- | 40[size=-2]o N | High at ~05:40 | High at ~05:40 | High during morning twilight at ~05:50 | High at ~05:30 | High at ~05:10 | 1- | Equator | High during morning twilight at ~04:50 | High during morning twilight at ~05:10 | High during morning twilight at ~05:00 | High at ~04:50 | High at ~04:50 | 1- | 30[size=-2]o S | Low in the eastern sky during morning twilight at ~03:50 | Fairly high in the northern sky during morning twilight at ~04:10 | Fairly high in the northern sky during morning twilight at ~04:00 | Fairly high in the northern sky during morning twilight at ~04:00 | Low in the northern sky during morning twilight at ~04:00 | 1- | 45P/Honda-Mrkos-Pajdusakova: A morning comet visible in very large telescopes
[size=-1]This comet begins the month in Virgo at magnitude 12.4. Look for a 3' coma. It should fade rapidly. FINDER CHART Latitude | Visibility December 31 | Visibility January 7 | Visibility January 14 | Visibility January 21 | Visibility January 28 | Nights Visible | 55[size=-2]o N | Fairly high in the southern sky during morning twilight at ~06:10 | Fairly high in the southern sky during morning twilight at ~06:20 | Fairly high in the southern sky during morning twilight at ~06:10 | Fairly high in the southern sky at ~05:50 | Fairly high in the southern sky at ~05:30 | 1- | 40[size=-2]o N | Fairly high at ~05:40 | Fairly high during morning twilight at ~05:50 | High during morning twilight at ~05:50 | High at ~05:40 | High at ~05:30 | 1- | Equator | High at ~04:40 | High during morning twilight at ~05:10 | High during morning twilight at ~05:00 | High at ~04:50 | High at ~04:50 | 1- | 30[size=-2]o S | Fairly high during morning twilight at ~03:30 | High during morning twilight at ~03:50 | High during morning twilight at ~03:50 | High during morning twilight at ~03:50 | High at ~03:50 | 1- | 49P/Arend-Rigaux: A morning comet visible in very large telescopes
[size=-1]This comet begins the month in Virgo at magnitude 13.5. Look for a 1' coma. It should fade slowly, moving into Coma Berenices by month's end. FINDER CHART Latitude | Visibility December 31 | Visibility January 7 | Visibility January 14 | Visibility January 21 | Visibility January 28 | Nights Visible | 55[size=-2]o N | High at ~05:20 | High in moonlight at ~04:20 | High in moonlight at ~05:10 | High at ~04:20 | High at ~04:00 | 1- | 40[size=-2]o N | High at ~05:20 | High in moonlight at ~04:10 | High in moonlight at ~05:10 | High at ~04:20 | High at ~04:00 | 1- | Equator | High at ~04:40 | High during morning twilight at ~05:10 | High in moonlight at ~04:50 | High at ~04:20 | High at ~04:00 | 1- | 30[size=-2]o S | High during morning twilight at ~03:30 | High during morning twilight at ~03:40 | High during morning twilight at ~03:50 | High at ~03:40 | High at ~03:50 | 1- |
[size=+1]Summary Data for [size=+1]This Month's Telescopic Comets [size=-1]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 | January 1st | January 15th | January 31st | Observations as of (UT) | Mag | Diam | Mag | Diam | Mag | Diam | C/2011 W3 (Lovejoy) | Ara | 5.6 | 5.5' | 7.3 | 5.4' | 9.5 | 3.4' | 2011 December 29 | C/2009 P1 (Garradd) | Hercules | 6.7 | 3" | 6.6 | 3" | 6.5 | 4" | 2011 December 23 | 21P/Giacobini-Zinner | Aquila | 8.9 | 9.6' | 8.4 | 9.8' | 8.0 | 10.1' | 2011 December 23 | C/2011 A3 (Gibbs)* | Scutum | 9? | 7'? | 9? | ? | 9? | ? | 2011 October 16 | 29P/Schwassmann-Wachmann | Corvus | 10.2 | 6.4' | 10.1 | 6.6' | 10.0 | 6.9' | 2011 December 7 | C/2010 G2 (Hill) | Cetus | 10.3 | 5.3' | 10.8 | 4.5' | 11.4 | 3.8' | 2011 December 23 | 78P/Gehrels | Pisces | 10.6 | 4.7' | 10.7 | 4.4' | 11.0 | 4.1' | 2011 December 23 | C/2011 Q4 (SWAN) | Bootes | 11.6 | 3.5' | 11.8 | 3.7' | 12.0 | 3.9' | 2011 December 7 | 45P/Honda-Mrkos-Pajdusakova | Virgo | 12.5 | 2.9' | 13.2 | 3.0' | 14.0 | 3.1' | 2011 December 7 | C/2011 M1 (LINEAR) | Centaurus | 13? | ? | 13? | ? | 14? | ? | 2011 September 25 | 49P/Arend-Rigaux | Virgo | 13.5 | 1.1' | 13.6 | 1.1' | 13.8 | 1.1' | 2011 December 25 | C/2010 S1 (LINEAR) | Lacerta | 13.6 | 32" | 13.6 | 32" | 13.6 | 31" | 2011 November 25 |
[size=-1]*In solar conjunction and not visible [size=-1]For the latest news and comet observations see the [url=http://cfa-www.harvard.edu/icq/CometMags.html]ICQ/CBAT/MPC: Recent Comet Magnitude Estimates[/url] page.The [url=http://cfa-www.harvard.edu/cfa/ps/Headlines.html]Astronomical Headlines[/url] page of the IAU is also a good source of information, particularly for recent discoveries.
[size=-1]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
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