Holmes Comet Coma Grows Bigger Than The Sun 245
coondoggie passed us a NetworkWorld article, as he does, noting that there is now an object in our solar system bigger than Sol. The Holmes comet has a huge coma, with a diameter scientists are now calculating to be larger than our own middle-sized star. "Scientists don't seem to have a guess as to how big it will ultimately become. The Holmes coma's diameter on Nov. 9 was 869,900 miles (1.4 million kilometers), based on measurements by Rachel Stevenson, Jan Kleyna and Pedro Lacerda of the University of Hawaii Institute for Astronomy. The sun's diameter, stated differently by various sources, is about 864,900 miles (1.392 million kilometers)."
Name (Score:4, Insightful)
Correct != pompous (Score:5, Insightful)
I don't think it makes the speaker sound pompous at all. Appealing to one's own ethos to strengthen an argument makes someone sound pompous. Quoting the law to justify an opinion about morality makes someone sound pompous. Using the word "Virii" to mean "more than one computer virus" makes a speaker sound pompous, and is also incorrect.
But simply speaking in a technically precise manner, especially to a science-literate target audience on a techie/geeky website, is not in the least bit pompous.
I would go so far as to call it "expected."
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I do not want to know how you would even know this.
Regarding the use of Sol for the Sun, yeah, it comes off a little pretentious, but it is the name given to it, even if it translates back to 'sun'. Latin names make everything sound cooler, anywho. Catapultam habeo. Nisi pecuniam omnem mihi dabis, ad caput tuum saxum immane mittam.
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Which is why SF often refers to "the sun" as "Sol", "the moon" as "Luna", etc. Probably where the poster picked up the habit.
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It's silly that they do that. We call our Sun, the Sun, and our moon, the Moon. It's simple and its accurate. If the inhabitants of other planets on other stars call their suns something, they could call it whatever they want, and I highly doubt they speak English... We might have to call Rigel "blahtak", or something.
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And 'we' do not call our sun, 'the sun,' except in English. Stop being so parochial, I mean, don't you think we shou
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Got any data to back that up? I know they call it Sol a lot in sci-fi paperbacks and on Star Trek, but do any scientists actually use that designation?
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It seems there (probably) exist 'ejected' planets which could sustain life.
http://www.world-science.net/exclusives/070910_sunless-planets.htm [world-science.net]
Apart from that, it is likely to be difficult to make predictions with regard to language (Living without Numbers or Time [spiegel.de]).
CC.
Re:Name (Score:5, Insightful)
Oh no! No. This is as bad as all those people who have started pronouncing Uranus "your-an-us" rather than "your-a-nus" because they think it sounds more scientific that way. As if sounding "scientific" is a good thing as opposed to trying to make things as understandable as possible (and funny). A sun is not a type of thing. You can say it to mean that, put it with a lower case 's' and people will know what you mean, but we have a word that specifically means that with no ambiguity and the word is star. We have been calling the Sun "the Sun" for a long, long time. Other languages have their own words for the Sun and they are direct equivalents. They don't mean "stars" or even "stars with planets around them." Each word means, quite specifically The Sun. And the interesting thing is that one of those languages is Latin and its word for the Sun is "Sol." It is the direct equivalent word with the same meaning. Why you think translating something into another language is suddenly correct and using the native word incorrect I don't know. But I am suspicious that it is that same creeping desire on the part of some people to sound "scientific." The English speaking world has used the Sun for centuries quite happily without any ambiguity which has appeared out of nowhere in recent years.
The overwhelming majority of English speakers call it the Sun and don't mean stars and wouldn't think to mean stars. Almost nobody calls it Sol. Why introduce confusion?
The Sun. The Stars. Uranus [rude pronunciation].
Thank you.
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By the way, the naming convention of "first in class" is also used in shipbuilding. There is a USS Nimitz, and, then, there is a Nimitz class carrier. The British came up with the first in class naval tradition and we copied it. For example, during World War II, they had the King George V, and the King George V class battleship.
So, to call the Sun a sun and the Moon the moon is entirely accurate and consistent with the human tradition. Certainl
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Re:Name (Score:5, Funny)
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Re:Name (Score:5, Funny)
Damn you (Score:4, Funny)
I'll never be able to use that number again. From now on I'll have to say 0.1% less than 100% or something like that...
Really, what possessed you to store it up there in the first place?!?
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Comet P/17 Holmes visibility, naked eye aspect (Score:5, Informative)
It looks exactly like this. [flickr.com]
That's a shot with a 50mm portrait lens - no telescope, no magnification, nothing. The comet is plainly visible as an orb, yes, just as the sun is.
Re:Comet P/17 Holmes visibility, naked eye aspect (Score:4, Informative)
I'm quite serious. Read the text I supplied with the image. The "orbs" you refer to are not resolved images of the edges of stars, they are simply burned out areas on the camera's sensor as the atmosphere's lensing moves the stars around over the many seconds of the exposure. Those stars are points of light, no more.
The burnout on many star occurs because stars, in relation to one another, can be literally millions of times different in brightness. Comet Holmes, while large, is not nearly as bright as many of those stars at any one sensor location, hence is does not burn out the imager and you get a considerably more accurate representation of it. Likewise, the dimmest stars still appear as pinpoints because when they are lensed to a random location, one or two passes over a sensor site aren't enough to result in a bright reading - that only happens at the centroid of the focus, essentially right where the star actually is.
Re:Comet P/17 Holmes visibility, naked eye aspect (Score:5, Informative)
Also, re your remark about post processing, I did three and only three things:
1) I used levels to push very faint background stars and sensor noise (which is fairly significant at ISO 3200) down towards or into black;
2) I pushed the color saturation up by about double to bring out the colors of the stars.
3) I clipped the portion of the image containing the comet and a few stars out and posted that fragment only, as opposed to the entire 10 megapixel shot.
None of which affected the capture of the comet in any significant manner. It isn't reflecting any particular color, so the change in saturation had no effect. The comet is quite bright, so pushing down the bottom-most brightness levels only served to trim a few pixels at the darkest edges of the comet. It appears just a trifle larger in the original.
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Read the FAQ (Score:5, Funny)
Slashdot seems to be very Earth-centric. Do you have any plans to be more galactic in your scope?
Slashdot is Earth-centric. We readily admit this, and really don't see it as a problem. Slashdot is run by Earthlings, after all, and the vast majority of our readership is from the Earth. We're certainly not opposed to doing more galactic stories, but we don't have any formal plans for making that happen. All we can really tell you is that if you're outside the solar system and you have news, submit it, and if it looks interesting, we'll post it.In other news... (Score:4, Funny)
Re:In other news... (Score:5, Funny)
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I know [msn.com] I'm going to hell
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Re:In other news... (Score:5, Funny)
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"Meteoric rise"? (Score:2)
Old Sol gets his comeuppance (Score:2, Funny)
oblig (Score:4, Funny)
Girl: But...
Man: ONCE AND FOR ALL!
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Not being flamebait here, just stating the unspoken (am I losing geek cred for pointing this out?).
Diameter? A bit hard to define. (Score:5, Informative)
I'd guess that the diameter that most people talk about when they're discussing the sun is that determined by the mean-free scatting path length of photons produced within the sun. Once the photons' probability for escaping the sun is higher than that for being scattered back into the interior, that's what we usually call the "diameter", and it accounts for the relatively sharp "edge" to the sun.
I could release a bunch of helium atoms on Earth's surface, and eventually they'd diffuse enough to be effectively larger than the sun's "diameter" as defined in the articles. It still doesn't mean a whole lot.
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Re:Diameter? A bit hard to define. (Score:5, Informative)
This depends - as the parent post already pointed out - entirely on how you define the diameter of the object in question. And - again, as the parent post already pointed out - the diameter of the sun is usually defined by that part of the sun which emits most of the photons that reach us from the sun. By most other definitions - and there are lots of them that do make sense - the diameter of the sun is larger. Much larger, in fact.
Incidentally, if you define the diameter of the sun using a measure that more-or-less matches the one used for defining the diameter of a comet's coma - namely, the diameter of the gas cloud emitted by the object in question - you'll get the entire heliosphere. Which is way larger than the coma of 17P/Holmes.
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Eeeww!!
Photon poo everywhere!!
Cheers
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"The average man thinks of celestial bodies in terms of number of times the sun would envelop/fit inside it. The average man also thinks of amounts of data in terms of libraries of congress. Geez... you are so out of touch."
Supply the elitist with this....
Girth? What size drill/tap bit?
Hell, the Holmsean man thinks of scexlestial bodies in terms of number of times the body would encompass his attached comet inside it. The Holmsean man also thinks of amounts of data in terms of masses of globules of
Cool, in theory (Score:3, Insightful)
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TBH, your post belies an attitude which saddens me... the fact that the visual impact of thing is more important than the scientific reality of it. It's part of the reason I avoid showing people nebulae and star clusters in my telescope. While they are scientifically fascinating objects, they simply don't have the real-life impact th
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It's not a matter of "more important", just that astrophysics and stargazing are two different things. The pulsar with planets is cool, even if we can't look up and see it. But Holmes has been hyped for its visual impact, which I'd say is .. lacking.
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Well, I think it's more accurate to say that, unlike, say, Hale-Bopp or Hyukatake, the visual impact of Holmes can only be truly appreciated if you understand the science of it. Consider, the coma of this thing is *huge*. Sure, it may look like a fuzzy ball, but it's a fuzzy ball with a truly massive angular extent, generated by an object that's barely resolvable as a point in an average telescope. That's pretty freakin' cool, i
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For those sighted adults to whom this isn't impressive visually, the situation has revealed people who have a woefully insufficient education, or an inability to comprehend the information conveyed by that education. The only choices remaining are, should we continue to let them go about their business, should we attempt remedial education, or should we put them
That's a big one (Score:2, Funny)
OBLIGATORY (Score:3, Informative)
"Bigger than..." (Score:5, Funny)
1. Beatles
2. Jesus
3. Holmes Comet
4. Sun
- RG>
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http://students.ceid.upatras.gr/~pirli/beatles/jesus.html [upatras.gr]
less dense (Score:2, Interesting)
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Spur of the moment thought (Score:3, Interesting)
Why not make a satellite hitch ride on one of these comets to the outer reaches of the solar system. Assuming they go there once every round, even hitching Halley's comet will get us further than Pioneer 1&2 have been in a shorter time, without wasting any precious fuel.
Lesser energy wasted means more energy available to scientific equipments onboard! So they can possibly carry many more equipments and more powerful transmitters.
Or hell, just hitch a ride on one of these for pretty much anywhere in the solar system. No need to wait 7 yrs to reach Saturn. Hitching a ride on one of these could get us there in months. They move *really* fast!
Re:Spur of the moment thought (Score:4, Insightful)
You want free energy for spaceflight? There are better ways [wikipedia.org]
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It didn't work out too well.
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It didn't work out too well.
He must not have done it right. I knew someone who made it work really well.
Once.
Re:Spur of the moment thought (Score:5, Insightful)
To hitch a ride on a passing comet, you can do one of two things:
1. Match velocities, and then land on it. -or-
2. Not match velocities, and then get smashed to bits by it.
Method 2 easily achieves your goal of travelling to the outer reaches of the solar system "without wasting any precious fuel". However, your satellite will no longer be functional, or even identifiable. But other than that, yeah, it's a great idea. :)
(Tell me Mrs. Lincoln, other than that, how did you enjoy the theatre?)
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John Holmes Comet Grows Bigger (Score:5, Funny)
And it's headed straight for your black hole, bay-bee.
Jupiter's Magnetosphere Still the Largest (Score:3, Insightful)
I'm pretty sure Jupiter's magnetosphere is still the largest object in the solar system.
Diameters (approx.)
Sun : 864,900 miles
Holmes : 869,900 miles
Jupiter's Magnetosphere : 16,000,000 miles
Wiki [wikipedia.org]
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But, I'm no scientist, so I digress. I had no clue that Jupiter had that much magnetic influence. How large is the sun's magnetosphere?
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Heh, I love those videos. I haven't seen that one before, thanks for the link.
There's precedent for this (Score:3, Funny)
Got a photo of it last night (Score:5, Informative)
In fact, I have several photos [flickr.com] of the comet taken over the past few weeks. They're not all cropped the same, but it's still quite apparent how much the comet is expanding. One of these days I plan to put together a composite photo, fixing the stars in place, and showing not only the expansion of the comet but also its motion relative to the stars.
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I see you used a 600mm telescope. I will try to take some pictures with my 500mm mirror lens. Unfortunatly I don't have a motor mount, so I don't know what I will get.
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Right now it's in Perseus, quite close to the brightest star. It's in the northeast as dusk falls, below Cassiopeia.
new career option? (Score:2)
Why would it ever stop expanding? (Score:3, Informative)
Re:Get out your Nikes and brew up a batch of Kool (Score:2)
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Re:Get out your Nikes and brew up a batch of Kool (Score:2, Informative)
Re:Get out your Nikes and brew up a batch of Kool (Score:2)
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I'm going back to freshman level science classes here but since most comets never come near the sun, but stay way out in never-never land, we have nothing to be afraid of her, right? Also, when comets DO come in for a pass at the sun (which is in theory possible for this guy) they condense and their centres form masses of ice and other solids. So this thing would shrink significantly if it ever did come in for a visit. Very cool piece of trivia though. I'm going to try using it this weekend
Shrink? Well, loose mass it would. The tail is the matter leaving the body of the comet. It is possible, while at aphelion the comet has sufficient gravity to attract more matter in the Oort cloud. But it is most likely comets have a limited life. So many trips around and they have evaporated.
The cool thing about these comets is they may leave a legacy. A legacy of meteor showers. (c=
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I thought dead you were, Master Yoda.
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Still amazing, though. I think it's incredible that after all this time, I can still see it in-city with the naked eye, a faint blur like someone took a pencil eraser to a star, growing ever-closer to Mirfak. And it's so well situated for evening viewing these days, too.
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Mod parent up (Score:3, Interesting)
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A user's comprehension?
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Re:Definition trouble. (Score:5, Interesting)
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They are saying the comet's coma [wikipedia.org] is bigger than the sun, not it's nucleus or it's "long tail of crap".