Last updated: August 20, 2010

Ephemerides for all of these comets (and many others) can be calculated at the IAU Minor Planet Center's web site. Recent reports of their brightness can be found at the ICQ's magnitude page, the Comet Observation Home Page [currently inactive] and the Yahoo! comet observations group. Discussions of these and other comets are carried out at the Yahoo! comets mailing list group, and links to images are at the Yahoo! comet images group. For basic comet observing information see the appropriate page at this web site.

NOTE ADDED NOVEMBER 21, 2007: There are numerous objects that are apparent asteroids but that travel in distinctly cometary orbits or are otherwise associated with cometary phenomena in some way, and it is entirely possible that these are extinct or dormant comets. When any of these come by I do attempt to observe them, but they are not eligible for adding to my comet tally unless observations show that they are indeed comets, in which case I'll add them to my list retroactively (as has happened once so far). This page will now include any such objects that I'm currently following at the time of any updates.

NOTE ADDED JULY 3, 2008: This page will now highlight in red print those comets that are 9th magnitude or brighter (and that are also easily accessible for observation) at the time of the update in question. Such comets should be detectable from suburban areas with small telescopes, and thus are those that are specifically recommended for "Countdown" participating students.

Comet 81P/Wild 2 (no. 463)

I suspect that I am probably about finished with this comet. During my observations of it earlier this month it appeared as a relatively vague diffuse object of 13th magnitude, and since it is now almost six months past perihelion passage and is continuing to fade it may be too faint to detect visually once the moon clears from the evening sky. The comet is currently located in eastern Libra 40 arcminutes north of the star Zeta Librae and 1 1/2 degrees south-southwest of the star Gamma Librae, and is traveling towards the east-southeast at slightly over 20 arcminutes per day; it passes one degree south of the star Theta Librae on September 3.

Comet Christensen C/2006 W3 (no. 422)

After over 2 1/2 years of following this comet I am probably close to being finished with it as well. After going through opposition a month and a half ago it seems to have faded quite distinctly, appearing around magnitude 12 1/2 to 13 during my observations earlier this month; the fact that it is very low above my southern horizon -- current declination -47.8 degrees -- and is also traveling through some rich Milky Way star fields has made it even more difficult to observe than it otherwise would be. The comet is currently located in northern Ara two degrees north of the star Alpha Arae and one degree east-southeast of the star Iota Arae; it is traveling just northward of due west at slighty under ten arcminutes per day, passing 40 arcminutes north of the globular star cluster NGC 6352 on August 26 and just over ten arcminutes south of the latter aforementioned star three days later. It should continue fading over the coming weeks, and at best I'll only be seeing it another two or three times.

Comet 65P/Gunn (no. 450)

This comet went through opposition earlier this month, and while it consistently appeared between magnitudes 12 1/2 and 13 during my observations around that time, the fact that it is now 5 1/2 months past perihelion passage suggests that it should be starting to fade and thus I probably will not be following it for too much longer. It is currently located in northwestern Microscopium two degrees west of the star Alpha Microscopii and is traveling almost due westward at a rather slow eight arcminutes per day; it reaches its maximum southerly declination of -33.5 degrees on August 25 and subsequently reaches its stationary point in mid-September.

Comet 103P/Hartley 2 (no. 477)

As expected, this comet has brightened some since I first picked it up early this month, appearing just brighter than magnitude 13 1/2 when I most recently observed it a couple of mornings ago. It is currently located in northern Pegasus two degrees north of the star Eta Pegasi and is traveling towards the north-northeast at half a degree per day, crossing into southeastern Lacerta on August 27 and into western Andromeda on September 6 before passing just east of the star Omicron Andromedae three days later. The comet is at opposition on September 1 and I expect it to brighten fairly rapidly over the coming weeks as it approaches the sun and Earth, perhaps by a full magnitude or more by early next month.

Comet Garradd C/2009 P1 (no. 478)

My tally's newest addition remains somewhat low in my southern sky, being located at a current declination of -37.3 degrees in northeastern Grus two degrees west-northwest of the star Beta Sculptoris; it is traveling towards the west-southwest at slightly under 15 arcminutes per day, passing one degree north of the star Upsilon Gruis on September 3 and going through opposition three days later. The comet has appeared as a small and somewhat condensed object of magnitude 13 1/2 ever since I initially picked it up earlier this month, and at most it should exhibit just a very gradual brightening over the coming weeks and months.

Comet 10P/Tempel 2 (no. 475)

Now a month and a half past perihelion passage this comet seems to have faded slightly during the recent past, although I could still see it in binoculars without much difficulty a couple of mornings ago as an object near 9th magnitude and with a coma about eight arcminutes in diameter; as has been true for the past few weeks, through the telescope this coma exhibits a small bright condensation distinctly off-center towards its southern side, giving it the overall appearance of a large, circular fan. It is currently located in central Cetus one degree east of the star 47 Ceti and four degrees northwest of the nearby solar-type star Tau Ceti; it is traveling towards the southeast at slightly over 15 arcminutes per day and passes 1 1/2 degrees west of the latter star on September 3 before reaching its stationary point four days later. The comet is nearest Earth (0.65 AU) on August 25 and is now a little less than two months away from opposition, and if it continues to exhibit the behavior it has shown during previous returns it should fade fairly slowly, and gradually grow more and more diffuse, over the coming several weeks.

Comet McNaught C/2009 K5 (no. 468)

This comet is gradually climbing higher into the northeastern morning sky after being in conjunction with the sun (38 degrees north of it) a month ago. It is currently located in northeastern Lynx 1 1/2 degrees north-northeast of the star 27 Lyncis and is traveling towards the south-southeast at a fairly slow seven arcminutes per day; it is at its stationary point on September 7 when it will be located one degree due east of that star. Now over 3 1/2 months past perihelion passage the comet has been fading during recent weeks, appearing close to 12th magnitude when I saw it a couple of mornings ago, and I expect it to continue this gradual fading during the weeks to come.

Comet 2P/Encke [not observed]

As recounted in the "Countdown" entry for this comet's 2007 return (and the update recently added to that entry), this year's return was very unfavorable for the northern hemisphere, and I never had a chance to attempt it as it was inbound to perihelion passage (which took place early this month). I have been reading reports from observers in the southern hemisphere which indicate that is now emerging into their evening sky, although the elongation from the sun is still fairly small (currently 26 degrees, but increasing by over a degree per day). It is currently located in southeastern Leo one degree northwest of the star 87 Leonis and is traveling towards the east-southeast at slighty over two degrees per day; it crosses into southwestern Virgo on August 22 and passes 15 arcminutes south of the "Sombrero Galaxy" M104 on August 30 (briefly traversing the northeastern corner of Corvus in the process before crossing back into southern Virgo three days later). The comet is nearest Earth (1.11 AU) on the 30th.

The reports I've read so far from the southern hemisphere suggest that P/Encke is currently somewhere between 8th and 9th magnitude. Historically, it tends to fade quite rapidly and grow diffuse as it recedes from perihelion, and thus I don't expect it to be visually detectable for more than about two or three weeks.