This is yet another of the intrinsically faint periodic comets that have been discovered during recent years. It was first detected in early December 2004 by the LINEAR program in New Mexico, and orbital calculations soon showed that it had passed perihelion five weeks earlier and was traveling in an orbit with a period of only 4.83 years; at the time of its discovery it was near its closest approach to Earth (0.44 AU). I managed to make one unsuccessful visual attempt for the comet shortly after its discovery was announced.
On the next return perihelion was expected to take place in early September 2009, but several searches from the southern hemisphere (from where it was better placed for observation) during mid-year were all unsuccessful. Then, in early August Rob McNaught with the Siding Spring survey in New South Wales reported that the apparent Apollo-type asteroid 2009 MB9 (that he had discovered from Siding Spring on June 29) had developed a small coma and was in fact a comet. Shortly thereafter, Hidetaka Sato in Japan suggested that 2009 MB9 was in fact identical to the expected LINEAR comet, and this was quickly verified. The initial prediction was only two days off, and to be honest a bunch of us are scratching our heads as to how we all managed to miss this identity between the two objects earlier.
Just a few days after Rob's announcement the comet disappeared into evening twilight, and passed 0.17 AU from Earth on August 5 before going through inferior conjunction with the sun a week later. By about the end of August it began emerging into the morning sky and I made plans to attempt observing it, although in addition to having to dodge the lingering monsoon activity that is typical for this time of year my skies have also been quite hazy, perhaps because of smoke from the Station Fire that is currently raging north of Los Angeles. (I've taken a strong interest in this fire, since I lived near the affected area in the mid-1980s while working at the Jet Propulsion Laboratory, and long-time friends and many of my old haunts -- including observing sites -- are in the vicinity.) My first attempt on the morning of the 29th (when the comet would have been quite close to a 12th-magnitude star) was unsuccessful, however on the following day Michael Jaeger in Austria reported that it was fairly bright and obvious on CCD images he had taken. After getting rained out the next day I tried again on the morning of September 1 and was able to detect a dim and diffuse object visually, although the comet was passing over a close pair of faint stars and I couldn't tell too much about it. Finally, on September 2 -- the last morning with any darkness before the coming full moon -- I was able to view the comet in a "clean" star field; it appeared quite diffuse and perhaps just brighter than 13th magnitude.
The comet is currently located in western Cancer near the star Zeta Cancri, and it remains within that constellation for the next few months, with its motion soon turning towards the northeast. These two observations that I've just made may well be the only ones I obtain of it, since moonlight will wipe it out for the next week and a half and by the time it is again accessible in a dark sky it will likely have faded beyond visual range. Furthermore, it turns out that the approach to Earth it made this return is the closest of the entire 21st Century, and not until 2058 does it even approach to within half an AU again -- thus, these are probably the only times I will ever see this comet.
462. COMET HILL C/2009 O4 Perihelion: 2010 January 1.28, q = 2.564 AU
A non-trivial percentage of the comets on my tally are faint, distant, and nondescript objects that for the most part are entirely unremarkable. This particular comet, which was discovered by Rik Hill with the Catalina Sky Survey in Arizona on July 30, 2009, is another example of such an object. (We've encountered Rik Hill's name before in "Countdown," and this makes the third comet of his overall that I have seen; this is his 15th comet discovery, of 16 so far as this writing.) I made a couple of unsuccessful visual attempts for it during August (in and around the monsoon activity when it would let me), and then on the first attempt I made in September (evening of the 13th) I observed an extremely faint (magnitude 14 1/2) and small suspect that I successfully verified the following two nights as being the comet.
Comet Hill is currently at opposition and will be nearest Earth (1.82 AU) in a few days, and thus is probably close to its maximum brightness, although since it is quite distant and is also approaching perihelion 3 1/2 months from now it should maintain this brightness for another month or more. It is currently located in far eastern Aquarius and, traveling in an orbit almost perpendicular to Earth's (inclination 96 degrees), plunges south-southwestward over the coming weeks, entering Sculptor at the end of this month and Grus during the latter part of October (where it remains for the next three months); it goes south of declination -40 degrees at the end of the first week of November. The comet's extreme visual faintness combined with its increasing southerly declination suggests I'll only be getting a handful of observations of it.
The one partially notable fact about Comet Hill is that it is the first comet on my tally with a perihelion passage on New Year's Day. Not only does it pass perihelion on the first day of a new year, by some reckonings this is also the first day of a new decade, and in addition to being the year during which my younger son Tyler graduates from high school 2010 can also be said to be "owned" (as was the year of 2001) by the late (and, in my opinion, great) science and science fiction writer Arthur C. Clarke.
463. COMET 81P/WILD 2 Perihelion: 2010 February 22.70, q = 1.598 AU
It appears that the summer monsoon is finally over here in New Mexico, and the autumn days and nights are becoming quite clear and crisp. With this change in the weather I've added another comet to my tally; not only is this one an old reliable friend, it has also become one of the most scientifically important of the periodic comets.
The comet was discovered in January 1978 by Paul Wild at the University of Berne in Switzerland -- a name we've already encountered earlier this year as a result of one of his other periodic comet discoveries. It was found to be traveling in an orbit with a perihelion distance of 1.49 AU and a period of 6.17 years, and calculations soon revealed that it had been perturbed into this orbit as a result of an extremely close approach to Jupiter (less than 0.01 AU) in September 1974. Prior to that it had been in a much larger orbit, with a perihelion distance of 4.9 AU and a period of over 40 years; when it had previously returned around 1927 it would have been too faint to detect with the equipment available then even if its existence had been known. (A much more distant approach to Jupiter -- 1.01 AU -- in June 1986 has placed the comet into its present orbit with a period of 6.42 years.)
Because it is considered a relatively "pristine" comet, and also because of its low orbital inclination (just over 3 degrees), P/Wild 2 has long been considered an attractive target for spacecraft missions. It was usually listed as either the primary or backup target for the on again/off again Comet Rendezvous/Asteroid Flyby (CRAF) mission that was developed during the 1980s but which was cancelled for budgetary reasons in the early 1990s. Finally, it got its visitor with the Stardust mission that was launched in February 1999. In January 2004 -- 3 1/2 months after the comet's most recent perihelion passage -- Stardust flew through the coma of P/Wild 2, passing 240 km (150 miles) from its nucleus. By means of an extremely porous and lightweight substance known as "aerogel," Stardust was able to collect samples of material from the coma, and it then returned these to Earth in January 2006. Study of these samples in the years since then has told us a lot about the formation of comets and the solar system as a whole, and there have been quite a few surprises; just last month, researchers announced that they had detected the amino acid glycine -- which is utilized by life here on Earth -- within the returned comet samples. (Stardust, meanwhile, having delivered its cargo to Earth, is now on its way to its next target: Comet 9P/Tempel 1 -- the "Deep Impact" comet from 2005 -- which it will encounter in February 2011. I've observed P/Tempel 1 on three returns, including the one in 2005 (no. 367), but the return in 2011 is quite unfavorable and it is doubtful that I'll be able to see it then.)
My personal history with P/Wild 2 extends almost all the way back to the very beginning. I followed it for three months during its discovery return in 1978 (no. 26); this was during the spring of my sophomore, or "youngster," year at the U.S. Naval Academy, and I vividly remember showing it to my then-girlfriend with whom I was madly in love but who was distinctly underwhelmed by the 11th-magnitude comet. Since then I've seen it on every subsequent return: in 1984 (no. 67); 1990 (no. 146); 1997 (no. 223), when it shared the sky with Comet Hale-Bopp C/1995 O1 (no. 199); and the "Stardust" return in 2003 (no. 332). The 2003 return was a very unfavorable one and I was only able to obtain a handful of visual observations of the comet; however, in late April of that year just as it was about to disappear into evening twilight I managed to obtain a dramatic CCD image of it while it was passing by the Crab Nebula M1 in Taurus. The astrometric measurements from this image turned out to be crucial in navigating Stardust to its target, and for a while the image was featured on the home page of the Stardust web site.
On its present return P/Wild 2 was recovered on October 20, 2008 by the Spacewatch program in Arizona. Following its conjunction with the sun earlier this year it recently has emerged into the morning sky, and I began trying for it after mid-September. During each of my first couple of attempts it happened to lie just a few arcminutes from a bright star and I couldn't see anything convincing, but on the morning of September 27 it was located in a good star field and I was able to follow the 14th-magnitude comet for an hour before dawn began to overwhelm it. With this observation this became the sixth return I have seen of P/Wild 2, and this is only the second comet, after 2P/Encke, that I have seen on six returns.
The current return turns out to be the most favorable one that P/Wild 2 has had since its discovery. At the time of my first observation it was located in central Cancer, three degrees south of the Praesepe star cluster M44, and over the coming weeks it tracks toward the east-southeast, crossing into Leo in mid-October (passing 1 1/2 degrees south of the bright star Regulus in early November) and into Virgo in mid-December, where it remains for the next 6 1/2 months. It is at opposition in late April 2010 -- only two months after perihelion passage -- and should reach a peak brightness between 9th and 10th magnitude, maintaining something close to this brightness from about February through about April. As it fades it should remain visible until July or August, when it will be located in Libra low in my southwestern evening sky.
As long as I remain active in observing comets, I should continue to be able to observe P/Wild 2, since I've been able to see it even during unfavorable returns, and there aren't any approaches to Jupiter coming up anytime soon to change its orbit (the next one being a distant 1.4 AU in 2046). The next return, in 2016 (perihelion mid-July), is fairly unfavorable, while the one after that, in 2022 (perihelion mid-December) is fairly good. Five returns from now, in 2042, the comet makes another very favorable return quite similar to this current one; I'll be turning 84 that year, and I guess we'll have to see if I'm still observing by then.
464. COMET 118P/SHOEMAKER-LEVY 4 Perihelion: 2010 January 2.30, q = 1.984 AU
This past week I was able to spend two days attending the International Symposium for Personal and Commercial Spaceflight that was held in Las Cruces, New Mexico. I thought it was a very good and worthwhile meeting, as a lot of new and interesting information (including the latest goings-on out at Spaceport America) was presented, and I was able to renew quite a few of my acquaintances in the space field and establish some new contacts as well; furthermore, my older son Zachary (a student at New Mexico State University) and his girlfriend were able to join me for the conference banquet. In addition to everything associated with the meeting itself, my experiences this week also brought back some interesting memories of the last time I attended this particular conference, two years ago; it was while getting ready to drive down the first morning that I checked my e-mail, read of the brand new outburst of Comet 17P/Holmes, and obtained my first observation of that most incredible comet (no. 414) before I departed. (I give a full account of those happenings in that object's "Countdown" entry.)
The occasion is nowhere near as dramatic, but I've now added another comet to my tally less than two days after my return from this year's conference; because of the shifting of calendar dates, this has taken place on the two-year anniversary of that remarkable observation. The comet in question is one of the many that were discovered during the late 1980s and early 1990s by the team of Carolyn and Eugene Shoemaker and David Levy during the course of the photographic survey program they conducted with the 46-cm (18 inch) Schmidt telescope at Palomar Observatory in California; they found it in early February 1991, the third of three comets they discovered within a span of three weeks. Orbital calculations soon showed that it had passed perihelion the previous July, and that it was traveling in a short-period orbit with a period of 6 1/2 years (currently, 6.45 years). The following return, in 1997 (perihelion in mid-January) was quite favorable, and I successfully obtained some observations of it (no. 222) as it reached a peak brightness near 12th magnitude. (Like the above comet, this one shared the sky with Comet Hale-Bopp C/1995 O1 (no. 199) at the time, and since I was rather preoccupied with that object I perhaps didn't follow this one as extensively as I otherwise might have.) The next return, in 2003, was unfavorable, although I did make one unsuccessful attempt for it after reports of an apparent small outburst.
On its current return Comet 118P was recovered on September 20, 2008 by the Mt. Lemmon survey in Arizona. I began searching for it last month, and after a few unsuccessful attempts then and earlier this month I finally spotted it on the morning of October 24 as a faint, 14th-magnitude object located in northeastern Orion three degrees north-northeast of the bright star Betelgeuse. This return is very similar to that in 1997 -- slightly better, in fact -- and I expect it to behave in a similar fashion. It remains in this part of Orion for the next several months; while currently traveling slowly towards the southeast, it reaches its stationary point in mid-November, then begins retrograde (westward) motion and passes a little over a degree north of Betelgeuse in late December before reaching its other stationary point a month later (when located two degrees northeast of the star Lambda Orionis, the star in "Orion's head") and thereafter turning back towards the east. The comet is at opposition shortly after mid-December (less than two weeks before perihelion passage) and as in 1996-7 should reach a peak brightness near 12th magnitude around that time; it should remain visually detectable until perhaps sometime in February.
The next return, in 2016 (perihelion mid-June) is another poor one, and I don't expect to see it then; curiously, however, six months before perihelion it passes only 0.04 AU from the bright main-belt asteroid (4) Vesta -- the current destination of the Dawn spacecraft that was launched two years ago, although Dawn will have left there 3 1/2 years earlier. Comet 118P passes 0.66 AU from Jupiter in June 2020, an encounter that reduces its perihelion distance to 1.83 AU and shortens its orbital period to 6.12 years; the subsequent two returns, in 2022 (perihelion late November) and in 2029 (perihelion mid-January) are both quite favorable and it might reach close to 11th magnitude on both occasions. Another approach to Jupiter (0.82 AU) in January 2032 restores most of the present orbital parameters but does so in a way as to prevent another favorable return like the present one for some time thereafter.
Meanwhile, though, the festivities on the morning of October 24 weren't quite done, as before the morning was over I added yet another comet to my tally . . .
465. COMET BOATTINI P/2009 Q4 Perihelion: 2009 November 19.92, q = 1.321 AU
Saturday morning, October 24, 2009, not only marked the two-year anniversary of that remarkable morning when I added Comet 17P/Holmes (no. 414) to my tally following its major outburst, it also marked the 19th occasion when I have added two or more comets to my tally during the same night. Just a little over half an hour after my first observation of the previous comet, I turned the telescope 25 degrees to the east-southeast and picked up this one that was about equally bright.
This comet is a new discovery, being found by Andrea Boattini on August 26, 2009 during the course of the Catalina Sky Survey in Arizona. We've already encountered Andrea's name before in "Countdown" as both his first and second comet discoveries are previous tally additions; he has since become a rather prolific comet discoverer, with this one being his 10th (and, at this writing, most recent) find. Most of the intervening ones have been quite faint and distant, although one that he found a year ago (P/2008 T3) turned out to be very interesting in that it was found to be identical to the lost periodic comet known as Barnard 3, which had been discovered back in October 1892 by the pioneering American astronomer Edward Barnard and which has the unique status of being the first comet to be discovered via photography. The comet, now known as 206P/Barnard-Boattini, was lost during the 116 intervening years between its two discoveries, and despite passing only 0.19 AU from Earth in late October last year does not seem to have become brighter than about 16th magnitude, thus indicating that, intrinsically, it is extremely faint. (I visually attempted it on a couple of occasions, without success.)
This newest Comet Boattini is also a periodic object, with the most recent orbital calculations indicating a period of 5.56 years. I had attempted it unsuccessfully on a couple of earlier occasions dating back to last month, and when I spotted it on the 24th it appeared as a small, moderately condensed, and fast-moving 14th-magnitude object located just a little over a degree west of the bright star Procyon in Canis Minor. It is traveling towards the east-southeast (currently at about 50 arcminutes per day) and crosses into western Hydra in early November (passing through the "head" of that constellation a week and a half later) and then into northwestern Sextans in early December; the motion then becomes more northerly as the comet crosses into Leo at the beginning of 2010, reaches its stationary point during the latter part of January, and then goes through opposition near the end of February. It is nearest Earth (0.58 AU) in mid-January, and meanwhile should reach its peak brightness (perhaps around 13th magnitude) during December before fading beyond visual range over the course of the next one to two months.
The orbit is still not entirely certain at this writing, but there does not seem to be have been any significant changes to it during the recent past (although there was a distant approach to Jupiter -- 1.5 AU -- in February 2008). Two returns from now, in 2020 (perihelion late December) Comet Boattini passes only 0.4 AU from Earth and should be about a magnitude brighter than it is this time around. If I'm still observing comets then -- and I probably will be, at least at some level -- I may very well be seeing this one again.
466. COMET 169P/NEAT Perihelion: 2009 November 30.30, q = 0.608 AU
Some of the comets that I've been able to observe all these past many years have been rather strange beasts. A case in point is provided by this object which, despite having an orbital period of only 4.21 years -- the second-shortest (second only to 2P/Encke) orbital period of any known periodic comet -- wasn't discovered and recognized as such until the fairly recent past.
The discovery took place on March 15, 2002, and was made by the Near-Earth Asteroid Tracking, or NEAT, program, which was the earliest of the automated survey programs for near-Earth asteroids. NEAT was developed by Eleanor Helin -- known affectionately as "Glo" to her friends and colleagues -- who was one of the original pioneers in near-Earth asteroid research; she was one of the "icons" whose name I read quite often when I was in high school, and I was privileged to get to know her moderately well on a personal basis later in my career. (Sadly, she passed away earlier this year). The first incarnation of NEAT, which utilized a 1-meter GEODSS telescope on Mount Haleakala in Hawaii, went into operation in late 1995 and over the course of the next 3 1/2 years discovered several near-Earth asteroids, two comets (one of these, C/1996 E1, being the first comet on my tally (no. 216) to be discovered via CCD), and the very unusual "asteroid" 1996 PW, which travels in a long-period orbit with a period of approximately 5000 years. After going off-line in mid-1999 NEAT returned a year later in a new incarnation, utilizing both the 1.2-meter telescope at the Maui Space Surveillance Site in Hawaii and the 1.2-meter Schmidt telescope at Palomar Observatory in California. While operational over the subsequent six years this version of NEAT discovered many near-Earth asteroids and 50 additional comets (of which I've observed nine, among these the conspicuous naked-eye comet C/2001 Q4 (no. 339)).
At the time of its discovery (which was made with the Palomar telescope) it appeared entirely asteroidal, and was assigned the asteroidal designation 2002 EX12. Orbital calculations showed that it had passed perihelion the previous July, and all indications were that it was nothing more dramatic than an ordinary Apollo-type asteroid (those with perihelion distances within Earth's orbit). It was followed for the next two months, and was observed when near aphelion in mid-2003; pre-discovery images were also identified on the red print of the second-generation Palomar Sky Survey taken in March 1989 and in Spacewatch images taken in April 1998. It was duly picked up again in May 2005 while en route to its next perihelion passage that September.
At the end of July some astronomers began to report that 2002 EX12 was accompanied by a short tail, and thus it was shown to be a small comet. I managed to obtain a couple of visual observations in early August (no. 378) as it was passing 0.15 AU from Earth; it appeared as an essentially stellar object of 15th magnitude. The real surprise, though, came shortly before mid-September, as the comet was approaching perihelion and after it had just gone through conjunction with the sun and was low in the morning sky at dawn; the Austrian amateur astronomer Michael Jaeger reported that images he had taken showed a distinct coma, and upon reading of this I successfully observed it as a rather "ordinary" diffuse comet near magnitude 11 1/2. I managed to observe it on a couple of additional occasions through early October as it faded by about a magnitude; its elongation from the sun remained small and it was never an easy object to observe.
Although it can be considered an "annual" comet, I am not aware of any observations of 169P that might have been made around the most recent aphelion; the first observations of the current return were obtained on May 19, 2009, by Russian observer Leonid Elenin remotely utilizing the Tzec Maun Observatory in New Mexico. Since we know so little about this comet, it wasn't clear whether or not we would get a repeat of the 2005 activity, and for a while it continued to maintain an asteroidal appearance. An image taken by Jaeger early in November, however, showed it as a very faint and diffuse coma, and shortly thereafter I made an attempt for it (when it was not only low in my southwestern sky after dusk, but was situated against the rich Milky Way star fields near the galactic center); I couldn't see anything convincing. Then, just recently I read that it appeared as a bright object in images taken with the Heliospheric Imager camera aboard the STEREO-B spacecraft (which was only 0.39 AU from the comet at that time), and I decided it was probably worth another attempt; on the evening of November 17 I successfully spotted it as a faint and diffuse moderately condensed object perhaps slightly brighter than 13th magnitude. (The very low elevation -- just barely over 10 degrees above my southwestern horizon -- and the very rich Milky Way star fields in central Sagittarius where it was located -- 1 1/2 degrees west of the bright globular star cluster M22 -- contributed to make this observation difficult, although I managed to observe distinct motion during the half-hour that I watched it.)
Even though I have just picked up this comet for my tally, I am probably already close to being finished with it. It is traveling southward fairly rapidly, and the elongation -- already down to 40 degrees -- is decreasing; furthermore, the moon is now entering the evening sky and will make further observations within the near future even more difficult. Shortly before the end of December the comet passes through inferior conjunction (35 degrees south of the sun) and enters the morning sky; it also enters southern circumpolar skies, reaching a peak southerly declination of -71.6 degrees on January 6, 2010. It then passes only 0.19 AU from Earth on January 12, and thus it is entirely possible that observers in the southern hemisphere may be able to observe it around that time; since we have so little knowledge of its brightness behavior, though, it's difficult to predict just how bright it may be then.
The next three returns of Comet 169P are all quite unfavorable, and I have no expectations of being able to observe it. The return in 2026 (perihelion shortly after mid-September) is virtually identical to the one in 2005 (with its passing 0.17 AU from Earth shortly before mid-August) and thus if I'm still active I may be able to see it then; the subsequent return in 2030 (perihelion early December) is very similar to this year's (with an approach to Earth of 0.20 AU taking place shortly before mid-January 2031) and it should potentially be observable again.
Readers may have noticed that I've been pretty mum on my personal doings during the recent past; in truth there isn't much to report. The personal life changes that I've been hinting at for so long now are still not too far underway yet, although I finally may have reason to believe that that won't be the case for too much longer; in the meantime, I'm continuing with my on-line teaching and I've been active with the local theatrical troupe, having performed in two Murder Mystery productions this month (and being the guy "whodunit" in one of them). My older son Zachary, a student at New Mexico State University, is coming home for the weekend for a rare visit, and his brother Tyler -- now a senior at Cloudcroft High School -- just recently tried out for All-State band. Through everything, life continues on . . .
UPDATE: To the best of my knowledge, there were no visual observations from southern hemisphere observers when Comet NEAT was close to the earth in early January 2010, and it appears that the coma that was visible when the comet was near perihelion had already dissipated by then. However, as the comet has receded from the sun and Earth -- and has also moved northward -- its nuclear region appears to have remained visible as a faint asteroidal object, and I was rather surprised when I picked it up in mid-February as a 15th-magnitude "asteroid." It had already gone through opposition early in February and should fade fairly rapidly as it continues pulling away from the sun and Earth, and thus I probably won't be following it for much longer (if at all) -- but all this goes to show that this is indeed a most unusual comet about which we still have much to learn.
467. COMET 30P/REINMUTH 1 Perihelion: 2010 April 19.54, q = 1.884 AU
Throughout all the years that I've been observing comets there have been times when I've managed to observe some of the periodic comets that, in all honesty, I never expected to observe (at least, not on the returns in question); indeed, this has already happened on a few occasions during the course of "Countdown." It has now happened again, with the addition of this particular comet to my tally.
The comet was discovered in February 1928 by Karl Reinmuth at the Konigstuhl Observatory in Heidelberg, Germany. Reinmuth was a prolific observer and discoverer of asteroids during the early decades of the 20th Century, and in addition to this comet he found a second periodic one (44P/Reinmuth 2) 19 years later (which I've successfully observed on two returns). His most famous discoveries were the near-Earth asteroids Apollo (in 1932) and Hermes (in 1937), the latter of these having just passed 0.0050 AU from Earth -- at that time, a record close approach for any known asteroid, and in fact a record which stood for over 50 years. Hermes was lost until its re-discovery by the LONEOS program in Arizona in 2003.
P/Reinmuth 1 has been a pretty dependable, if unremarkable, visitor ever since its discovery; it has only been missed once, and the current return is the 11th at which it has been observed. Its current orbital period is 7.34 years, and on this return it was recovered by the LINEAR program in New Mexico on August 20, 2009. I unsuccessfully attempted it on several occasions during the somewhat mediocre return in 1988, but successfully observed it on the relatively favorable return of 2002 (no. 329), when it reached 13th magnitude; I didn't see it until two weeks after perihelion passage, which had led me to believe that it might be one of those comets like 6P/d'Arrest that stays faint until perihelion and then brightens dramatically. The current return is another mediocre one only slightly better than the one in 1988, and I wasn't even planning on looking for the comet; however, some of the reported CCD magnitudes on the recent "Observations of Comets" Minor Planet Electronic Circulars (MPECs) published by the Minor Planet Center seemed to indicate that it might be bright enough to attempt. On my first attempt, on the evening of December 8, I successfully spotted the comet as a very dim object slightly fainter than 14th magnitude, and observed distinct motion over the course of the next hour. (Incidentally, this observation came during the midst of a two-day-long power outage caused by extremely high winds during a winter storm that had struck a couple of days earlier; meanwhile, there is still a significant amount of snow on the ground from an earlier storm that produced the second-largest single-storm snowfall -- 22 inches, or 56 cm -- of any storm that has hit since I moved to Cloudcroft in 1995.)
The comet has just gone through opposition, and will be nearest Earth (1.18 AU) shortly before the end of December. It is currently located in northwestern Orion 7 1/2 degrees north-northwest of the star Bellatrix (Gamma Orionis) and is traveling slowly towards the west-northwest, crossing into south-central Taurus shortly before mid-January 2010 and reaching its stationary point (some five degrees east of the Hyades star cluster) shortly before the end of that month, at which time it begins direct (eastward) motion. The comet spends the next two months traversing Taurus (and passing half a degree north of the Crab Nebula M1 shortly before mid-March) before crossing into Gemini near the end of that month and then into Cancer during mid-May; at perihelion it will be at an elongation of 73 degrees and located 2 1/2 degrees east-southeast of the star Epsilon Geminorum. In terms of its brightness, I'm not quite sure what to expect; ostensibly it should brighten by perhaps half a magnitude or so by January and then begin fading, but if the asymmetric behavior I suspected during the 2002 return is real it might continue brightening and remain visible for several more months. We'll just have to see . . .
Once I'm done with the comet on this return I'm not sure when, or if, I'll be seeing it again. The next two returns, in 2017 and 2024, are both very unfavorable (perihelion taking place in mid-August both times; a moderately close approach to Jupiter -- 0.52 AU -- in November 2020 shortens the orbital period and decreases the perihelion distance slightly), while the return in 2031 (perihelion mid-November) is perhaps slightly more favorable than the current one. The return after that, in 2039 (perihelion at the end of January), is very favorable -- the best since the comet's original discovery, in fact -- and if I'm still alive and observing comets at the age of 80 perhaps I'll see it then.
And meanwhile, with the addition of this comet to my tally I am now two-thirds of the way through "Countdown." A reasonable projection based on the rate I've been adding comets lately suggests I should reach no. 500 around the end of the year 2011, although a lot will depend upon what new discoveries I'll be able to see. In the near future, there may not be too many additions for a while; in fact, during 2010 there are only five expected periodic comets that I have some reasonable expectation of seeing -- a list which doesn't include this one -- and I've already picked up three of those. There are some recently discovered long-period comets arriving next year that I should be able to observe; two of these could potentially reach naked-eye brightness, although I doubt if either of them become very bright. We'll see what nature brings . . .
468. COMET McNAUGHT C/2009 K5 Perihelion: 2010 April 30.02, q = 1.422 AU
My first addition to my comet tally in the new year -- and, by some reckonings at least, in the new decade. And it features a name that has appeared several times already in "Countdown," although this is Rob McNaught's first appearance in my tally in over a year and a half. Since the last time we saw his name Rob has been busy extending his record of being the champion comet-discovering person in history; this particular comet was his 49th discovery, and his total as of this writing is now 54. This is the 16th comet of his that I have seen, and his name is now in 4th place on the list of names that appear most often in my tally.
Like all his other recent discoveries, Rob found this comet during the course of the Siding Spring survey that is being conducted in New South Wales. At the time of its discovery on May 27, 2009 the comet was deep in southern circumpolar skies at a declination of -74 degrees, but since it is traveling in an orbit almost perpendicular to the ecliptic (inclination 104 degrees) it has been heading slowly northward ever since. After being in conjunction with the sun in early December it has now begun emerging into the morning sky, and I briefly spotted it (in and around clouds) with the 20 cm telescope on the morning of January 26 and got a better view of it in good sky conditions the following morning. (Observing has been a somewhat "iffy" proposition lately, since here in Cloudcroft we have been experiencing a continuing series of winter storms; this has been, in fact, one of the heaviest winters we've experienced in recent memory, probably due at least in part to the recent El Nino in the Pacific Ocean.) The comet appeared as a dim and somewhat condensed object between magnitudes 11 1/2 and 12.
Comet McNaught is currently located in northern Sagittarius near the large star cloud M24, and is low in my southeastern sky before dawn. Over the next few weeks it travels towards the north-northeast -- close to, and almost parallel with, the galactic equator -- through Scutum (passing just 15 arcminutes east of the "Wild Duck" star cluster M11 in late February), Aquila, and Vulpecula, and enters Cygnus in early April. The comet then continues heading northward, being nearest Earth (1.26 AU) two weeks later, and when at perihelion at the end of that month will be entering northern circumpolar skies. It reaches a peak northerly declination of +83 degrees shortly after mid-May, and although it begins heading southward after that it remains in far northern skies for some time, being near a declination of +58 degrees when it goes through conjunction with the sun a little after mid-July. After moving over into the northern hemisphere's morning sky after that it remains in the constellation Lynx for the next several months as it recedes from the inner solar system.
Since it never gets especially close to either the sun or Earth Comet McNaught probably won't get too bright. Based upon its present brightness, it should peak around 9th magnitude during April and May, be near 11th magnitude when it goes through conjunction with the sun, and remain visually detectable until perhaps September.
Not only does Comet McNaught come at the beginning of a new year and a new decade, it also comes at the beginning of a new chapter in my personal life. Those big changes that I've been hinting at for so long are finally coming to pass, and while I'm not quite ready to reveal them just yet, I hope to be doing so soon -- most likely after I've added another couple of comets to my tally. By the time I've said farewell to this particular comet that new chapter of my life should be well underway.
And meanwhile, at least one more Comet McNaught is inbound, and should be showing up on my tally within a few months. While it probably won't become very bright, that one has the potential of reaching naked-eye visibility, and thus may help me in getting this new life chapter started off in a positive way from the astronomical side of things.
469. COMET CATALINA C/2009 O2 Perihelion: 2010 March 24.42, q = 0.695 AU
Almost from the time I began "Countdown" three years ago I have been hinting that there would be some major changes in my personal life -- which, to an extent, will also affect Earthrise -- coming up, but I have been very scarce concerning details as things have played out during the intervening months. At long last, these changes are starting to come to pass, and while I'm still not quite ready to share with "Countdown" participants just what those are, I should be doing so within the fairly near future. This particular comet may well go down in my mind as the comet most linked with these changes, and there are facets associated with it that perhaps make it an appropriate object for such a linkage.
The comet was discovered on July 27, 2009 by Alex Gibbs during the course of the Catalina Sky Survey that is being conducted from Arizona; it appeared entirely asteroidal on the discovery images, however, and it wasn't until additional images with other telescopes revealed cometary features that its true physical nature was realized, hence the name "Catalina." Since that time it has brightened slowly as it has approached the inner solar system, and after being in conjunction with the sun shortly before mid-January 2010 has recently begun emerging into the morning sky.
Comet Catalina is traveling in a steeply inclined retrograde orbit (inclination 108 degrees) and over the next few months follows a path through the sky that is strikingly reminiscent of that followed by Comet Hale-Bopp C/1995 O1 (no. 199) exactly thirteen years ago. It is currently located in northeastern Aquila a few degrees northeast of the bright star Altair, and for the time being is traveling towards the northeast roughly parallel to the galactic equator, entering Vulpecula in late February and Cygnus in early March. Over time its motion turns more easterly, and just before perihelion passage it is again in conjunction with the sun (44 degrees north of it); a couple of days later it is nearest Earth (0.81 AU), is at its farthest north declination (+44.6 degrees), and passes three degrees north of the Andromeda Galaxy M31.
After all this the comet moves over into the evening sky, initially traveling eastward through eastern Andromeda and Perseus, and then takes a turn towards the southeast, entering Taurus in early April and passing a few degrees northeast of the Hyades star cluster shortly after the middle of that month. It then enters northwestern Orion, and at the beginning of May will be located some four degrees west of the "head" of that constellation. I will lose it in twilight within the next one to two weeks, although it theoretically remains accessible for observers in the southern hemisphere for some time thereafter; it is again in conjunction with the sun (36 degrees south of it) at the end of June.
While I never expected Comet Catalina to be anywhere near as bright as Comet Hale-Bopp was, I did entertain some hopes that it might reach naked-eye brightness when around perihelion. At this writing, that seems pretty unlikely now; when I first picked up the comet on the morning of February 13 (following a couple of brief unsuccessful attempts in late January) it appeared as a rather dim and somewhat condensed object near magnitude 12 1/2. If it brightens "normally" it probably won't be any brighter than about 9th magnitude when near perihelion, and it will likely have faded to magnitude 11 or 12 by the time I lose it in evening twilight. There is always a possibility, of course, that it will "loosen up" some as it approaches perihelion, and/or might be brighter after perihelion than before, although I wouldn't hold my breath for any such scenarios; meanwhile, for what it's worth the comet appears not to be a "new" comet making its first visit in from the Oort Cloud (the most recent return having been some 175,000 years ago, although the perturbations it's experiencing during the current return will place it into a shorter-period orbit that will bring it back in a little under 4000 years), and since it will be in inferior conjunction when at perihelion we may get a slight forward scattering enhancement of its brightness around that time. As it true with any other comet, we'll just have to see what it actually does as it makes its visit through the inner solar system.
So, despite the almost uncanny resemblance that Comet Catalina's path through the sky bears to that taken by my namesake comet thirteen years ago -- an era which, of course, saw many changes in my personal life -- it appears likely that I won't have the bright comet I was hoping for to mark the changes I'm going through now. But that's OK, though, since I still have this comet -- and several others -- to observe as I undergo the current changes, and that has been a constant feature of my life for over forty years now and should remain so for the foreseeable future.
UPDATE: I'll have to admit that I've been disappointed that Comet Catalina didn't brighten very much after I first picked it up, and in fact it was only 12th magnitude when I saw it in late February shortly before the full moon. While waiting for the moon to clear the morning sky I began to read reports from CCD observers that suggested that the comet was starting to disintegrate, and when I was able to observe it again on the morning of March 13 I saw that, while it had brightened some during the interim -- to about magnitude 11 1/2 -- it was indeed distinctly less condensed that it was earlier, appearing as a small and only slightly condensed diffuse cloud.
If Comet Catalina is indeed disintegrating, then it is difficult to make predictions as to what to expect during the coming few weeks; it is entirely possible that there will be little, if anything, left to see as it passes through perihelion, and subsequently. Intrinsically, it is rather faint for a long-period comet, and it is not too unusual to see comets like this start to disintegrate as they get close to the sun; it appears that we may now be seeing another example of this phenomenon.
UPDATE: Although I was still able to see the comet as a very faint and diffuse object when it moved over into the evening sky at the time of perihelion passage, by early April I was no longer able to detect it, suggesting that the disintegration process that began a month earlier is now complete (or close to it). It is conceivable that CCD images may still show it as a pale diffuse cloud, but it would seem that its period of visual detectability is over.
470. COMET HILL C/2009 U3 Perihelion: 2010 March 20.25, q = 1.414 AU
Fifteen years ago, i.e., in March 1995, my family and I moved into the residence east of Cloudcroft, New Mexico, that we have called "home" ever since. Within three weeks of that move I added the first addition to my comet tally -- Comet P/Clark 1994t (no. 197) -- from the new residence, and less than four months after that came the discovery of Comet Hale-Bopp C/1995 O1 (no. 199) that forever changed my life. In addition to many other things that have happened during the intervening years, I have witnessed the passing away of my father, Nile Hale, in March 2002, and I have seen my two sons Zachary and Tyler (ages 8 and 2, respectively, at the time of the move) grow into fine young men; Zachary (now 23) graduated from Cloudcroft High School in 2005 and now lives in Las Cruces, New Mexico, where among other things he attends New Mexico State University, and Tyler (who will turn 18 in a little over two weeks) will graduate from Cloudcroft High School in two months and later this year will join his brother at NMSU.
One of the true constants in life, however, is change, and as I have been hinting at in these pages almost since the very beginning of "Countdown" I am in the process of going through some significant changes in my personal life. I'm still not quite ready to disclose all of those changes yet, but one thing I can discuss now is that I am relocating -- to a place that is relatively close by, and that I will discuss in more detail in a future tally posting. Along these lines, my final night of astronomical observations from my long-time residence was the night of March 18-19, and among a few other objects I observed five comets. The last of these, which I observed shortly before the onset of dawn, was Comet Siding Spring C/2007 Q3 (no. 441), and after I finished with that observation I turned my telescope towards the globular star cluster M70, where a similar observation all those years ago made my life very interesting thereafter. There were, alas, no comets nearby this time . . .
The second of the two comets I observed in the evening was the confirmation of this new addition to my tally, the last addition I will have made from that residence. The comet was discovered on October 21, 2009 by Rik Hill during the course of the Catalina Sky Survey in Arizona, and is traveling in a long-period (slightly over 2000 years) ellipse with an inclination of 51 degrees; it was at opposition in early November, was nearest Earth (1.14 AU) in early December, and has just passed through perihelion. I began searching for it shortly before mid-January, but for the next two months my attempts were unsuccessful and I was on the verge of giving up on it (although it's worth mentioning that the rich Milky Way star fields in Andromeda and now Cassiopeia that it has been traveling through certainly didn't help in trying to see it). On the evening of March 16, however, I suspected an extremely faint and very diffuse object traveling through the rich star field the comet was supposed to be in that night, and on my "final night" two nights later (when I saw that the comet would be briefly located in a relatively "clean" star field) I successfully confirmed that earlier suspect. It appeared as a diffuse and slightly condensed 14th-magnitude hazy cloud that traveled through that "clean" field during the half-hour or so that I followed it.
Comet Hill is currently located in eastern Cassiopeia a couple of degrees north of the star Epsilon Cassiopeiae (the easternmost star of the "W"), in northern circumpolar skies but best observed in the northwestern sky after dusk. It is traveling towards the northeast at approximately 3/4 of a degree per day (and, having drawn to a distance of 1.44 AU from Earth in early March is now coming closer again, to a minimum distance of 1.41 AU shortly after mid-April), crossing into eastern Camelopardalis during the second week of that month and reaching a maximum northerly declination of +76.5 degrees at the same time as that minimum distance from Earth. It then begins turning towards the southeast, crossing into northwestern Ursa Major at the beginning of May, passing 1 1/2 degrees southwest of the bright spiral galaxy M81 a little over a week later, and then passing a few degrees west of the "bowl" of the Big Dipper shortly after the middle of that month.
Ostensibly, Comet Hill is close to its maximum brightness, although it is predicted to remain somewhere near its present brightness through early April. How it actually behaves, of course, is something we'll just have to see, and in fact it is entirely within the realm of possibility that the two observations I've made thus far will remain the only ones I obtain of it. In that case, Comet Hill will have, coincidentally, made its one very brief appearance in my life at the same time as all the "interesting" changes that are taking place right now. But there are plenty of other comets to observe, both now and in the future -- just as there are (hopefully) plenty of experiences left in this thing we call "life."