C/2006 P1 — another Comet McNaught
Published on Jan 4, 2007 at 6:35 pm.
25 Comments.
Filed under comets, skywatching.
Robert McNaught seems to have an amazing talent for finding comets. He’s got nearly three dozen that he’s found. One of them is just about to swing by the Sun. This comet’s official designation is C/2006 P1. It has been diving towards the Sun, and will be at its closest point on January 13. On that date, it will be only 0.17 Astronomical Units from the Sun, just over half of the distance of Mercury at its closest approach.
Comets are big balls of ice and rock that originate in the outermost part of the Solar System. Something disturbs their orbit, and they can sometimes dive in towards the Sun. If they get close enough, say within a dozen AU of the Sun, then the heat from the Sun starts to sublimate the ices. They boil off, and blow dust grains with them. The solar wind and light pressure push the gasses and dust outward away from the Sun, producing the comet’s tail. The ices (water ice, frozen ammonia, frozen methane, frozen carbon dioxide) are easily vaporized by the Sun, so we call them the comet’s volatiles. Each time that a comet passes the Sun, it has fewer volatiles to spew out, and eventually the comet loses so many volatiles that it no longer produces a tail, and it looks just like an odd asteroid. The more volatiles that are available, typically the bigger and brighter the tail. Also, the closer to the Sun that a comet gets, typically the bigger and brighter the tail, since it is the Sun’s heat that is boiling off the volatiles in the first place. Some comets have gotten so close to the Sun that they totally evaporate and are gone forever. This one shouldn’t do that, though! But, it is getting close to the Sun.
Now with C/2006 P1 getting closer to the Sun, it already is developing a pretty tail. Often the tails are better after closest approach though. Here I’ve posted a photograph of the comet taken by Haakon Dahle and posted on the Spaceweather.com web site. Also on that site, you can find finder charts for the comet. Space.com has also posted an article about the comet, with more finder charts. Already the comet is naked eye visible if you’ve got a clear and dark horizon and no city lights to worry about. And, it probably should be getting brighter, but by next week it will probably be a bit too close to the Sun to see. It should return the following week, though.
Right now, predictions are that it should be rather bright near its closest to the Sun. But how bright remains open to question. Some are calling for it to be several dozen times brighter than Venus, and others are precting a magnitude no brighter than the North Star. It is really very hard to predict what an unknown comet will do. Comets that come by regularly, we observe and get an idea of what to expect. But this comet has never been seen before. In fact, this is probably the fist and only time that this comet has been by close to the Sun. With an eccentricity currently estimated to be just over 1 it will never again come by. First time comets are notoriously unreliable, and are often a bit dimmer than the ones that have been by a few times. That might seem counterintuitive, since the first time by they should have the most volatiles. But, perhaps impacts, fractures and so forth expose more fresh material in more frequent comets. At any rate, my observations have been that first time comets are very unreliable. I remember getting all excited in the past over some comet that was going to be spectacular, only for it to just barely be visible in binoculars. So, I really don’t think that this particular Comet McNaught will be the comet of the decade. Of course, I could be wrong, and I frequently am where comets are concerned. But, the folks at the Minor Planet Center have an ephemeris set that predicts a maximum magnitude of 2.4. That’s bright for a comet, but nothing that a non-astronomer would likely notice unless it were pointed out to him. There’s another thing that I need to point out, too, about these magnitude estimates. These estimates are for the integrated magnitude of the comet — that is the magnitude that you get if you take all the light and bunch it up into a point. The comet will be a little spread out, so it will look dimmer than a star of the same magnitude to your eye.
Of course, this comet is a complete unknown. We have found in our studies of comets over the last few years that no two seem to be alike. Some have more ice than others, some have more rock, some are put together better, and some are about to fall apart. In fact, comets have been known to fall apart when the pass near the Sun. When the crumble, they often expose a lot of fresh volatile material, and they flare up quite brightly. So, if that were to happen, then the upper brightness estimates might be right. I really doubt that such a thing will happen, though. Most likely, it will stay comparative dim (at least as far as city folk are concerned). But if you get a chance, then go try to look for it. Check out the finder charts from the sites that I indicated above.
-Astroprof
Update: Since I wrote this, Comet McNaught has really flared up and has really become impressive! Despite claims that it rivals Venus, it actually appears much dimmer to the eye. Still, it ought to be visible if you have a good horizon and not too much light pollution or haze. I was in the American Astronomical Society Meeting in Seattle all this past week, but on the way home I got to see the comet and even take some photos. They are here. Also, I’ve posted an update on the comet here. Â
A Ler…-- Rastos de Luz on January 5, 2007 at 8:46 am: 1
[…] “C/2006 P1 - another comet Mcnaught“, no Astroprof; […]
James Willis on January 7, 2007 at 6:47 pm: 2
My Dad & I love to look up at the night sky, when we take the dog for her last walk of the day at 10 PM, we have done this for a couple of decades on & off, & I thank you for your sight it is imformative & easy to understand for those of us who are enthusiastic amateurs.
Great site
Elias and Barbara on January 9, 2007 at 6:05 pm: 3
Today was amazing. Saw the comet from Bsyside NY at 6:57AM right before sunrise. It was extremely low to the horizon and by 7AM EST it was washout by dawn’s light. Then 15 minutes after sunset saw it low in the west from Prybil Beach in Glen Cove NY. It was brighter and the tail was more distinct. Will try again tomorrow!!
Andy Murray on January 10, 2007 at 1:17 am: 4
I’m no astronomer, but I looked out my window this afternoon and saw the comet in the SSW. I live north of 70, on Baffin Island, and from here it was many times brighter than the brightest planet. We’re still in the polar night up here, and reportedly it was visible from before 0800 to around 1530 local time. I’ll be checking again tomorrow…
Astroprof’s Page » Comet McNaught is getting impressive … on January 10, 2007 at 2:55 pm: 5
[…] … and I am missing it!!!!! Since I’ve gotten so Seattle, it has been cloudy and rainy nearly the entire time. OK, I am lying. It’s been entirely the whole time. In the meanwhile, Comet McNaught, which I talked about earlier, seems to be living up to its hype (uncharacteristic for comets!). But, with the clouds, I am missing it! However, SpaceWeather.com has a nice photo gallery of the comet that you should check if you have similar cloud issues. Otherwise, go out and see it for yourself. […]
Darren Addy on January 11, 2007 at 9:03 am: 6
Quote: So, I really don’t think that this particular Comet McNaught will be the comet of the decade. Of course, I could be wrong, and I frequently am where comets are concerned. But, the folks at the Minor Planet Center have an ephemeris set that predicts a maximum magnitude of 2.4.
- - -
With McNaught currently at -2 and now expected to rival Venus
http://www.itwire.com.au/content/view/8458/1066/
it has a chance of being the Comet of Several Decades. In fact, I believe that Comet C/1927 X1 (Skjellerup-Maristany) was the last comet visible in daylight (when just 5 degrees away from the sun).
It is interesting to note the similarities in the orbits and orientation of earth to comet between McNaught
http://neo.jpl.nasa.gov/cgi-bin/db_shm?sstr=C%2F2006+P1+&group=all&search=Searchand Skjellerup-Maristany:
http://neo.jpl.nasa.gov/cgi-bin/db_shm?sstr=Skjellerup-Maristany
Might make a nice follow-up post!
Astroprof on January 11, 2007 at 9:10 am: 7
Yes, very interesting. Comets tend to surprise me. They are really interesting objects, and so poorly understood. There’s a long held feeling that comets are boring ice balls, and they are all alike. However, evidence is mounting that there are numerous classes of comets, each quite different and distinct, and each very interesting. I really didn’t think that this one would live up to the hype, but apparently it did! Sadly, I still haven’t seen it, since it’s been cloudy here!
Astroprof’s Page » Comet McNaught (C/2006 P1) Finally ! (with pictures!) on January 12, 2007 at 3:26 am: 8
[…] Well, I have finally gotten to see the comet. I’ve been in Seattle all week at the 209th Meeting of the American Astronomical Society (the professional organization for astronomers in North America). The meeting was great, and we had great presentations, and I learned a lot. But, it was cloudy and rainy all week (except at the end, when it was snowy). Last week, I had written about Comet C/2006 P1 (Comet McNaught) that was about to sweep around the Sun. At the time, I had downplayed suggestions that this was going to be a spectacular comet. After all, far too often a comet is predicted to be spectacular, but then it fails to live up to expectations. Well, this one apparently has. Despite it being hailed as the brightest comet in 30 years by many, I feel that Comet Hale-Bopp was better. But, this one is no slouch, either! It is supposed to rival Venus in magnitude, but to the eye Venus looks clearly brighter. That is because the light from the comet is spread out more. […]
Elias and Barbara on January 12, 2007 at 6:12 am: 9
Glad you finally got to see the Comet! We visualized it again low in the west after sunset on January 11th from Roslyn Harbor New York. It was visible just minutes after the sun set. We also had cirrus clouds in the way but the comet was able to shine through. Will try one last time tonight. My trick is I return to the exact same place so I can utilize landmarks to see it immediately. Hope all are enjoying the same view. Of note, it has entered the SOHO telescope’s field of view.
Astroprof’s Page » Update on Comet McNaught on January 12, 2007 at 2:46 pm: 10
[…] Definitely, if you are in the Northern Hemisphere, go out tonight or tomorrow night and look for the comet low in the southwestern sky, right near where the Sun sets a few minutes after sunset. It is worth it. The comet continues to brighten as it sweeps by the Sun. There is some speculation that it might break apart, and if it does, then it will really get bright as a lot of fresh material is exposed to the Sun’s heat. It turns out that the stuff that comets are made of is really pretty poor as a heat conductor, so normally only the outer meter or less is actually heated by the Sune enough to sublimate. So, when one breaks apart, there is suddenly a huge surface area that sees the sunlight. Personally, I don’t think that the comet will break apart, but these things are really pretty unpredictable. As you might recall, I didn’t think that it would get this bright, either! […]
J Gontesky on January 12, 2007 at 7:40 pm: 11
Great information - thanks for the solid detailed lowdown on McNaught. I’ve been fortunate enough to photograph it each of the last four nights (see my page) but a winter storm will hide McNaught from our view here in the central plains. I’m curious to see what kind of show it puts on for the southern hemisphere after emerging from behind the sun.
rocket on January 14, 2007 at 5:29 am: 12
comets have long been thought of as the harbingers of catastrophe and pestilance . do you see any corrolation of ancient mans thoughts and modern mans science ??
Astroprof on January 14, 2007 at 10:06 am: 13
Hello, Rocket.
If you want to believe that a comet is a harbinger of evil, then you can certainly find bad things that come along after the comet. Such things are always happening, so you will always find them, wether or not the comet is there. On the other hand, if you think that the comet brings good news, then if you look for them, you’ll find good things happening, too. Take your pick. Comets have come a few years before wars and the cure for smallpox.
Besides, there are comets out there all the time. At any given moment, there are usually several comets visible to amateur astronomers. This is simply a brighter than average naked eye comet. There was another naked eye comet, in fact, just last October, called Comet SWAN (C/2006 M4). It didn’t get as much press attention, and was dimmer so you had to get to dark skies to see it, rather than in the city. If anything was to be a harbinger of anything, then that one certainly would have been, because it was different from most comets in that it was green .
Astroprof’s Page » Comet McNaught now very bright on January 14, 2007 at 2:32 pm: 14
[…] When I first posted about the comet, it was looking like it would be pretty bright, but I definitely didn’t expect it to be this bright. Even my update is now outdated! It is passing only 0.17 AU from the Sun, so that tends to make comets bright. Comets are made of frozen gasses and ice mixed with dust and rock. Close to the Sun, the ices (water ice as well as frozen gasses) sublimates, and blows off into space, producing a bright blue tail. Dust is blown out, too, producing a yellow tail. Both tails point outward away from the Sun, but the dust tail tends to curve a bit. Often on the way in, you see the blue tail, and the dust tail becomes more prominent the closer that you get to the Sun. The gas tail, also called an ion tail, is technically called the Type I tail. It appears bluish because CO+ , a common ion in the tail, scatters blue light more effectively than other colors (much in the way that gasses in our atmosphere scatter blue light more effectively, making the sky blue). The dust tail, technically the Type II tail, reflects sunlight. But, all this material thrown off has to be accelerated away from the nucleus of the comet. Before that happens, it forms a cloud surrounding the little solid chunk of frozen material that is the nucleus. This cloud is the coma, or head of the comet. […]
rocket on January 15, 2007 at 5:05 am: 15
thanks astroprof for your reply. your comet was the harbinger of great joy and wonder in the eye piece of my telescope. Regards to you. Rocket.
John Kingman on January 15, 2007 at 11:27 am: 16
Why doesn’t it appear that McNaught’s tail is pointing away from the Sun in the SOHO images, now that it is heading away from the Sun?
Astroprof’s Page » Comet McNaught’s Tail on January 15, 2007 at 1:08 pm: 17
John, that is an excellent question. Rather than answering it in a comment, I decided to have an entire posting on the answer. That can be found here.
Brian Watson on January 17, 2007 at 5:54 pm: 18
I live on the west coast of Australia and have last night been to the coast to view the comet. Thousands of people came out last night to see and is getting quite a bit of press too. My question is , when, if someone knows , will this comet come around again..if at all? Anyway spectacular sight last night about 45 mins after sun set into the Indian Ocean.
Astroprof on January 17, 2007 at 6:04 pm: 19
This comet is in a hyperbolic orbit. It will never be back again.
Igor Prario on January 18, 2007 at 12:36 pm: 20
What is the distance from Earth to the comet C/2006 P1?
How much it measures the plasma-tail at 17 Jan?
Astroprof on January 18, 2007 at 2:56 pm: 21
Right now (it changes continually) C/2006 P1 is about 45,000,000 kilometers away from the Sun and 130,000,000 kilometers away from Earth. The length of the tail depends upon how you measure it, but a ballpark estimate would be about 6 to 8 million kilometers.
Caddie Cadstar Roberts on January 24, 2007 at 4:39 am: 22
Hi. I live in a small town in South Eastern New South Wales, Australia. My question is how fast is the comet travelling? Will it change speed? And when is the next significant comet to be expected? These beautiful and magical phenomenon are so powerful. You just can’t seem to look away. I aspire to one day be involved in the discovery and surveillance of these celestial giants. I hope! Thanks. Caddie
Astroprof on January 24, 2007 at 9:53 am: 23
Hello, Caddie.
The comet is currently moving a bit over 63 kilometers per second. It is slowing down as it pulls away from the Sun (the Sun’s gravity is pulling on it).
As for when the next impressive one will be, …, I can’t say. The most impressive ones are often the ones that have not been seen before, so the next one so impressive has not been discovered yet, and we will just have to wait until it comes in. But comets this bright often only come twice per century.
Ishan on February 1, 2007 at 3:56 pm: 24
can any one answer me that i live in Bayonne Nj and i need to see the comet so how can i see it please answer me back on my mail address that is ishanp2003@yahoo.com and make the sub as very important
Astroprof’s Page » Crystals and Comet McNaught on January 9, 2008 at 1:59 pm: 25
[…] One year ago, C/2006 P1 (Comet McNaught) was making all sorts of news as it put on a wonderful naked eye performance. At the time, though, I was at the AAS Meeting in Seattle, where it was rainy the whole time (except for when it snowed!). I finally got to see the comet, though, from the window of the airplane on the plane ride home to Texas. That is where I took the photo below. That was the only time I saw the comet, though, as it was cloudy back in Texas from the time I arrived until the comet was no longer visible. […]