Planet Finder Catches a Comet!
Written by Tammy Plotner
Who can forget last October, when astronomers all over the world were astounded by the huge outburst of Comet Holmes? The eruption was the largest for more than a century. (Click on image to animate.) Fortunately for the world, a UK telescope was in the right place and the right time to capture the first images of this once-in-a-lifetime event.
The SuperWASP-North facility on the island of La Palma was built by UK scientists to discover planets around other stars. The 8 cameras that make up the system operate robotically, automatically scanning large areas of the sky each night. By coincidence, at 2339 GMT on the evening of 24 October 2007, it was pointing towards Comet 17P Holmes.
"By the time SuperWASP spotted the comet, it had already brightened by a factor of 1000" explains Dr. Henry Hsieh. "But this was still almost 3 hours before anyone else noticed it." (The lucky astronomer and the honor belongs to amateur astronomer Juan Antonio Henriquez Santana who saw the eruption from Tenerife. Score a point for those of us who scan the skies!). Over the next 2 hours the comet continued brightening, until SuperWASP could no longer accurately measure it - it was too bright for the cameras.
Orbiting the Sun, comets are mainly composed of frozen gases and microscopic solid particles in a small solid nucleus. As they pass by our solar system's nearest star, they heat up, releasing gas pockets and other frozen materials. Most of us understand outgassing and the properties of cometary tails, but during this outburst, Comet Holmes released a large amount of its material all at once.
Two days after the eruption began, sunlight reflecting from the ejected material had made the comet one million times brighter than it was originally making it easily visible to observers across the northern hemisphere. Dr. Hsieh comments:
"Over the next few weeks, SuperWASP continued to observe Comet Holmes as the cloud of dust and gas surrounding the 3-km diameter nucleus of the comet steadily expanded. By 31st October, the cloud was already 900,000 km across or more than twice the distance from the Earth to the Moon. Using our SuperWASP observations, we measured the speed of expansion of the outer edge of this cloud to be over 1500 km per hour and by 17 November measured the size of the cloud to be more than 2 million km across - much larger than the Sun."
Two weeks after the outburst, SuperWASP scored again - the faint and delicate tail of Comet Holmes composed of the gas released from the nucleus. As astronomers watched over the next few weeks, this tail gradually faded and moved away from the comet. Although many images were gathered by astronomers around the world, the precise cause of the outburst is still a mystery. All they know right now is that it happened once before - in 1892 - and may well happen again. Keep watching!
Filed under: Comets
April 2nd, 2008 at 9:47 am
What is that black shape passing by from right to left in the upper part of the animation?
April 2nd, 2008 at 9:49 am
I would like an explanation for the dark artifact moving right to left as well.
April 2nd, 2008 at 10:27 am
The image in the background is very noticeable! I wonder what it could be…hmmmm!
April 2nd, 2008 at 11:04 am
This seems to be a tiny (one pixel) moving something; the ring is a software tracker which pursues it. Another tracker is actually tracking the comet itself.
April 2nd, 2008 at 3:09 pm
if you think thats strange you should youtube
sts-180 its a satellite image thats freakin creepy
April 2nd, 2008 at 7:51 pm
Hey LLDIAZ, could not find anything on youtube under sts-180?? You got a link?
April 2nd, 2008 at 10:46 pm
Try STS-80
April 2nd, 2008 at 11:36 pm
So the evidence of alien intelligence is lights appearing on Earth?
Oh, wait, there were also well studied photographic artifacts.
I'm convinced.
April 3rd, 2008 at 8:32 am
Most curious about the second object, if it is, is the jagged line it follows.
April 3rd, 2008 at 2:32 pm
Sts-80 was a '96 shuttle mission, why is it that whenever there is 'solid proof' of extra terrestrials the image is always grainy and greatly out of focus? The only thing creepy about the YouTube footage is the British fellow forming all these conclusions without giving any credentials. Think about it for a moment, we can easily see small man made satellites crossing the sky at night and its hard to miss the ISS when it goes over. The ISS has an approximate diameter of 50 meters and the UFOs described in the film have an estimated diameter of 1.5 miles, if these things periodically wiz about in the upper atmosphere thousands of people would witness them every time they showed up. Lastly, its a thunderstorm, isn't it likely that it's merely an electromagnetic phenomenon such as ball lightning or stable plasma? Think what you will, but I remain wholly unconvinced in the alien visitor theory from this clip.
April 3rd, 2008 at 4:47 pm
You copied a typo from the press release: The outburst began late on Oct. 23, 2007 and was known widely in the comet community by the morning of Oct. 24!
Daniel
April 3rd, 2008 at 10:42 pm
Caching comets are easy.
April 4th, 2008 at 12:57 am
There are no aliens. UFOs by definition can be anything.We're spending billions upon billions looking for spooks [AKA:Sagans]. We are simply arrogant little snits who love to waste other folk's dough [TAXES] and call it science.
April 4th, 2008 at 6:56 am
Daniel,
"The 8 cameras that make up the system operate robotically, automatically scanning large areas of the sky each night."
To me, this sentence says the operation is controlled by a computer guided program on an agenda, not aimed on a whim.
"By coincidence, at 2339 GMT on the evening of 24 October 2007, it was pointing towards Comet 17P Holmes."
By coincidence means to me that it just happened to be pointing in that area at that time. Astronomers are rather picky about logging times.
"By the time SuperWASP spotted the comet, it had already brightened by a factor of 1000" explains Dr. Henry Hsieh. "But this was still almost 3 hours before anyone else noticed it."
Dr. Hsieh's comment leads me to believe the outburst was already occuring when the SW system began filming the area by coincidence. Since night doesn't happen at the same time all around the Earth, the news of the outburst was already breaking worldwide. I would say Dr. Hsieh comment that it "was still almost 3 hours before anyone noticed it." could either refer to the SuperWASP team monitoring the images, or "anyone" could also be a professional slip meaning other professional observatories.
As a reporter, it is not up to me to change dates or times on press releases - even if I believe them to be erroneous. Nor can I change statements given by others to make them read what we want them to say. As an accredited observer, if a professional observatory tells me their scope was pointed at X at 2339 GMT on the evening of 24 October 2007, then I must take that at face value.
If you feel their dates are in error, I would suggest you visit SuperWASP and explain that Dr. Hsieh's press release to the RAS is incorrect.
April 5th, 2008 at 1:16 pm
> As a reporter, it is not up to me to change dates or times on press releases - even if I believe them to be erroneous.
Oh no, as a science journalist it is your duty to check press releases for accuracy - and correct them, esp. when they are so obvious as this one (of course I told the RAS, too). I thought Universe Today wanted to be something more than one of the countless copy&past press release mirror sites?
For the timeline of the Holmes outburst see the October 24 entry in my Cosmic Mirror and the "visual observation reports" links in the sidebar: By mid-day UTC on Oct. 24 tthe comet had already brightened by about a million.
April 5th, 2008 at 6:36 pm
Guess what, in Hsieh's own version of the press release, the mistake has already been fixed - while the R.A.S. version has yet to follow suit.
Case closed (while the issue of how science reporters should handle press releases has been taken care of in this CAP Journal article last fall).
April 6th, 2008 at 12:27 pm
FYI, here's what the R.A.S. spokesman just wrote to me: "Hi Daniel
Oops… I'll correct it online but as you say the odds of many people [that's the science writers community I was talking about; DF] checking is slim… Thanks for letting me know.
Regards
Robert"
April 7th, 2008 at 9:42 pm
That is a great article, Tammy. I really appreciate what you do for the astronomical community.
I always read your stuff and see if I can glean some insights to what I'm trying to accomplish when I go observing.
You have my utmost admiration.
April 8th, 2008 at 5:06 am
Thank you, Marcellus… Your words mean a lot more than you know.
April 8th, 2008 at 10:41 am
> That is a great article
Hmm, didn't Tammy state very clearly that this is in its essence a copied press release without any changes (and one where the glaring error still hasn't been corrected although the original source has long done so)? An "article" is something different, don't you think?
It would be most helpful if Universe Today would make it more obvious what is genuine new content (which I appreciate and often link to, actually, including a recent Tammy article) and what is a blindly copied press release! Sometimes the original source is linked to at the end - but not here …