Compared to some stars, our Sun is something of a wimp. It just sits there all by itself, shining all the time, hardly changing in temperature, brightness, or mass.
But not all stars are so boring. I present to you this amazing image of the star HD 87643:
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[Click to embiggen.]
HD 87643 is the star near the middle of the picture, surrounded by the weird glowing material. And OK, so the name of the star is a little boring, but the star itself is very cool indeed. Or hot. And it’s not even one star.
HD 87643 is what’s called a B[e] giant star. The B means it’s a hot star, and since it’s a giant (or possibly even a supergiant) it will one day end its life in a titanic supernova explosion. The [e] means its spectrum has emission lines. Usually, when you take the spectrum of a star you see absorption lines, dips in the spectrum indicating the presence of various atoms or molecules (see my recent post about this for some details). You only see emission lines — bright features in the spectrum — if the star is surrounded by gas that is being lit up by the star making it glow just like a neon sign. It’s very rare to have stars do this, but HD 87643 is one of ‘em. B[e] stars are thought to have very strong stellar winds, which means they are blowing a lot of gas into space, and it’s this gas that’s glowing.
Another funny thing about HD 87643 is that it’s blasting out infrared light, far more than a B star should. That’s a giveaway that it’s also surrounded by dust. The dust absorbs light from the star, warms up, and then re-emits that light as heat. So the dust glows brightly in the infrared, and it’s that excess radiation that betrays its presence.
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But the really funny thing about the star is that it changes in brightness on a somewhat regular schedule, dimming and brightening every 50 years or so. Moreover, a close-up of the star image (shown here) indicates it’s surrounded by spherical shells of material, which means it’s blasting off vast amounts of mass every few decades! What the heck is going on here?
To figure that out, astronomers used an interferometer, a telescope designed to take incredibly high-resolution observations of the star (you can get all the details in their journal article). What they found was that HD 87643 is actually two stars!
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You can see that in the extreme close-up image here. One is the massive B star, and the other is a less massive, somewhat cooler star. They are separated by a mere 7 or 8 billion kilometers (4-5 billion miles) — to give you a sense of scale, this is only about twice the distance of Neptune from the Sun. Given that the stars lie about 5000 light years away, this image is pretty phenomenal!
It’s not well determined yet, but it seems that they orbit each other with a period of roughly 50 years, and the orbit is stretched out into a very elongated ellipse. Every half-century or so, the stars swing past each other and have a very close encounter. When they do, their mutual gravity rips material off each other, and this matter goes screaming off into space, expanding outward to make the smoke rings seen in the picture above. Some of this material stays in orbit around the more massive star, creating a thick ring of dust which absorbs the starlight and generates the IR excess.
What a phenomenal system is HD 87643! Two hot stars, one inevitably marching toward doom, the other on an orbit that drops it down into the maelstrom. When it does, chaos ensues as matter is flung outward into space, gas that glows like a beacon in the galaxy, a circular target with a bull’s-eye in the center announcing the star system’s odd presence.
It always amazes me that we can figure this stuff out just from a few observations of a star, especially one that’s 50 quadrillion kilometers away! But in astronomy, with advanced technology comes advanced knowledge. We learn more and more about the sky around us, increasing our understanding of the Universe.
And it’s a pretty cool place.
Image credit: ESO/F. Millour et al.
August 5th, 2009 at 12:23 pm
The name isn’t boring, you’re just not used to it!
August 5th, 2009 at 12:24 pm
Awesome.
But (pedant mode on) …
I always thought it was “Be star” not B[e] or if the ‘e’ for emission was bracketed there it was (curved) brackets not [square] ones. Plus isn’t the decimal numeral meant to be there too – Eg. B5e?
And it’s a pretty cool place. Umm … Given the surface temperature of these stars esp. the B type one @ circa 20,000 degrees Kelvin – I’m not so sure that “cool’s” the word!
(Pedant mode off.)
3 Questions :
1. Could we have exact spectral types for the binary & masses (pref. in solar masses) please?
2. Also what magnitude is this pair? Is this star visible with unaided eyesight, binoculars or telescope?
3. Does this make this binary system a shell star – or stars?
——-
PS. Woo-hoo! First post!
August 5th, 2009 at 12:24 pm
HD 87643 is the star near the middle of the picture, surrounded by the weird glowing material. And OK, so the name of the star is a little boring, but the star itself is very cool indeed. Or hot. And it’s not even one star.
The name is not boring! You just need to get used to it!
August 5th, 2009 at 12:32 pm
Would the smaller star be obliterated when the B[e] goes off? Have we ever seen that happen?
August 5th, 2009 at 12:44 pm
@ Dr Phil Plait – On the use of “embiggen”. (Yuk. It even hurts me to type that word.) Sigh.
I really wish you would cease & desist foisting this ugly, unfunny and lame non-word on everyone, Dr Plait. Please!
I strongly think that “embiggen” is analogous to using the term “theory” to mean approximately “wild guess.” It degrades the English language and is an utterly unnecessary bit of dumbing down / playing up to the breifly funny Simpsons pop culture joke.
A joke which was originally very mildly “funny” exactly because both “embiggen” and “cromulent” are clearly nonsense words rather than real ones. Turning them by common usage into pointless neolgisms would actually defeat the very message the joke was sending.
Besides what exactly, BA, is your objection to using the correct word for the situation – “enlarge”?
Will you please, please reconsider your English language abuse here, BA?
August 5th, 2009 at 12:44 pm
Dr. Plait, I thought you said the universe is a pretty dangerous place. Okay, so 3K makes it cool too.
August 5th, 2009 at 12:46 pm
D’oh! Bunny beat me by name changing & consequent invisibility – @ a guess ‘Bunny’ used to be “Naked Bunny with a Whip” – right?
Actually while ‘Bunny’ is shorter I kind of preferred the old version.
Another question if I may – which sorta ties in with the stellar mass one too :
Do we know the age of these stars and thus their likely fates?
Is the B type star massive enough to end as a type II supernova or will interactions between the binary components create another Algol-like situation with stellar mass-exchange taking place and preventing this?
Will the two evolve into a Mira style red giant & white dwarf pair and then lead to a recurrant novae scenario and ultimately perhaps a type Ia white dwarf supernova?
Or can’t we pin this down specifically enough yet?
August 5th, 2009 at 12:48 pm
Cool stuff, but one minor quibble. The “B” does not necessarily mean that the star will end its life as a supernovae; the majority of B-type main sequence stars will make white dwarfs. But B-type giants and supergiants, like this star, are massive enough to explode.
Plutonium, the [e] not only indicates emission lines, but that the emission lines are forbidden transitions, which are typically indicated with brackets. (See http://en.wikipedia.org/wiki/Forbidden_mechanism)
August 5th, 2009 at 12:54 pm
Grammar Nazi scares me. I like “embiggen” and I laugh every time I see it.
August 5th, 2009 at 12:54 pm
I have a question. How did they determine that the star dims and brightens with a period of about 50 years? Have they been observing it for 100 years or was this determined some other way?
I’m assuming from the article that they determined that the start was periodically changing in brightness before they figured out that it was really two stars.
August 5th, 2009 at 12:55 pm
Presumably given a year or so the position of the stars will change considerably. A few shots of this system animated over a few years would be pretty phenomenal!
August 5th, 2009 at 12:55 pm
@Grammar Nazi:
Your personal dislike of a neologism does not entitle you to dictate whether or not others may use it. Nor has it so entitled you in the past, nor will it so entitle you at any point in the future. Good day.
August 5th, 2009 at 12:56 pm
Grammar Nazi,
I think the use of new and interesting words embiggens the language.
P.S.: You misspelled “briefly”
August 5th, 2009 at 1:02 pm
Wow. Methinks Grammar Nazi needs to embiggen his vocabulary. The word is obviously being used tongue-in-cheek. Dr. Plait uses it often. Besides, to some of us it is still funny, because we get the reference, and the original context. And so I wholeheartedly say, embiggen away! Srsly! Squee!
Side note: fascinating star system. Seeing that it is a binary system, shouldn’t it read “Two B[e]“? Or are they not both in the same category? What class would the smaller star fall under?
Interesting as always!
Lonestar
August 5th, 2009 at 1:03 pm
@Plutonium:
It’s all about the sort of emission lines the stars have. Be stars have allowed lines, B[e] stars have forbidden lines. And they all have square brackets in their names.
The cognoscenti pronounce them B-bracket-e, if I remember right.
August 5th, 2009 at 1:05 pm
(Cont. from #7 – Editing to add but ran out of editing time again.
)
… Or will the Be star be far enough away from its companion and massive enough to erupt as a type II supernova instaed and eventually lead to a neutron star/ black hole & red giant pairing creating a catacylsmic variable?
Can we tell how this system is likely to evolve &, if so, on what sort of approx timeline?
—-
PS. Hey, if I can’t get ‘first post’ honours here maybe I can still try for ‘Most posts”?
August 5th, 2009 at 1:08 pm
Grammar Nazi, did you not read my comments the last time you came here with your nonsense? The very term “grammar nazi” is a neologism, so coming here to complain about new words being used is ironic and hypocritical.
August 5th, 2009 at 1:11 pm
Kurtis, you’re (mostly) right; in this case it’s a B2 which will definitely explode. It’s known in this case that the star is either a giant or supergiant, which I neglected to mention! So I corrected the text.
August 5th, 2009 at 1:11 pm
When it come to the source of your life and continued existence, boring = GOOD!
I really wish you would cease & desist foisting this ugly, unfunny and lame non-word on everyone, Dr Plait. Please!
LOL! GRAMMAH NAZI HAZ A SAD!
Keep using “embiggen”, Phil.
Language evolves and grows, Grammar Nazi. Slang is a part of the human experience.
I used “embiggen” in a program recently. There’s a window that hides some less used controls. If you right click on it, you get a popup menu that says “Embiggen Window”. It will resize the window to make the controls visible.
August 5th, 2009 at 1:14 pm
@ 10. Jim Seymour Says:
Grammar Nazi, I think the use of new and interesting words embiggens the language.
I disagree and think it harms & degrades our language.
We already have a perfectly good and accurate term for the meaning that the BA is trying to convey – ‘enlarge.’
Why complicate & confuse peoples understanding by substituting a superflous joke word for a real correct term?
P.S.: You misspelled “briefly”
So I did – but at least I used an actual word!
I don’t claim to be perfect by any means but I don’t deliberately introduce lexicographical errors like using “embiggen” instead of “enlarge” and I don’t see why others would wish to make their writing worse and our language poorer by doing the latter.
@ 17 BA – Yes, I read your posts there & I disagree entirely.
My tag here is a slang term which I thought I’d already explained earlier – ‘nazi’ here having the humerous sense of perfectionist; one who insists on getting ‘aspect X’* right.
It is quite different to the situation where you replace the real and accurate term ‘enlarge’ with a nonsense word. Now, can you please answer my question regarding what your objection to the perfectly good word ‘enlarge’ is?
Can you please, answer my point on the analogy between bad use of scientific terminology and your own bad use of English here?
Most of all, can you please reconsider your views here?! Please!
—–
* Aspect X in this case being correct English language use. In the famous ‘Seinfeld’ episode ‘aspect X’ was the soup, and so forth.
August 5th, 2009 at 1:16 pm
Our sun, more massive than roughly 90% of the other stars, is a “wimp”?!?
August 5th, 2009 at 1:22 pm
I just wanted to say thanks for this article. I appreciate the Good Astronomy articles whenever you post them.
To Word Jew… Best. Username. Ever. (In response to Grammar Nazi)
I agree, “embiggen” is a perfectly cromulent word!
August 5th, 2009 at 1:25 pm
@ Word Jew:
LOL @ your name, vis. Herr Nazi.
haw haw!
August 5th, 2009 at 1:29 pm
I have a question. Why is it that when we look at pictures of distant stars they they appear to have 4 pointed tips of light radiating away from them like a + sign? Is this because of the equipment used to photograph them? Or is it just a property of light?
August 5th, 2009 at 1:32 pm
i cant wait til embiggen is added to the dictionary so grammar nazi has to eat his hat and he will be so angry about the word being in they’re i am righting this as bad as i can so he gets mad and has to read it, i am surprised how hard it is to right this badly!
August 5th, 2009 at 1:42 pm
Grammar Nazi, I bet you’re really fun at parties.
BA is obviously being goofy and playful. That’s okay in a blog; it’d be a different matter if it were an article on the front page of the NY Times. It’s all about context, and if you can’t tell the difference, that’s your problem.
August 5th, 2009 at 1:44 pm
Beautiful pictures… making me almost tear up here. I don’t even work as an astronomer, but since I found your page here I’ve totally become immersed with our galaxy. I love it! It’s so awesome. Wish I didn’t live in freakin’ DC, though. Can’t see jack in the sky at night… sucks, too, cause the Perseids are gonna be invisible thanks to all the light (and regular) pollution around here.
Oh well. Take good pics of them for us who live in crappy cities with too much light.
August 5th, 2009 at 1:45 pm
@Grammar Nazi
I find your use of compound punctuation to terminate a sentence rather vulgar: “?!”
August 5th, 2009 at 1:46 pm
Grammar Nazi: Language evolves. Deal with it. Words are used by a community to convey an idea that the community agree is associated with that word. This community agrees that embiggen and enlarge are synonyms.
I came across the word embiggen for the first time in a Bad Astronomy post, having never seen the original pop culture reference (Simpsons, you say?). I had zero, none, nada problem with immediately discerning its meaning. There. Communication successful. Language once again fulfills its one and only function.
August 5th, 2009 at 1:46 pm
They could run for congress, especially as Republicans.
Hey Grammar Nazi:
embiggen, embiggen, embiggen, embiggen, embiggen, embiggen, embiggen, embiggen, embiggen
embiggen, embiggen, embiggen, embiggen, embiggen, embiggen, embiggen, embiggen, embiggen
embiggen, embiggen, embiggen, embiggen, embiggen, embiggen, embiggen, embiggen, embiggen
embiggen, embiggen, embiggen, embiggen, embiggen, embiggen, embiggen, embiggen, embiggen
August 5th, 2009 at 1:47 pm
Yeah…hmmm…embiggen…yeah…
Not to change the subject but…
So how did they determine that the star (or in this case stars) dim/brighten every fifty years?
I thought I’d ask again since my original question (now #10..who knows what it will be shortly) might get lost in all of the grammar controversy.
August 5th, 2009 at 1:49 pm
Methinks thou doth protest too much. Languages evolve despite your efforts, and they are better because they do. You’d best confinimate your examinerations and discomplitudes to severier strategery.
BTW: Thanks, Phil, for writing a great article, and for embiggening our language!
August 5th, 2009 at 1:53 pm
Azam, it’s an artifact of the telescope used to take the picture — most big telescopes nowadays are reflectors, so they have a secondary mirror sitting in the path of the light coming in. The light diffracting around the mirror and its support structures on its way in makes the cross pattern. If the picture was taken with a refractor (telescope with lenses), you wouldn’t see the spikes.
As for me, personally I like having as many neologisms and ways to say stuff as possible. Eventually the boring/useless ones will drop out of use, and we might get shades of connotation to distinguish words. (Think about how many words English has for ‘really big’ — gigantic, titanic, enormous, humongous, immense, vast…)
August 5th, 2009 at 2:04 pm
@20 Grammar Nazi says:
Why complicate & confuse peoples understanding by substituting a superflous joke word for a real correct term?
“People’s” gets an apostrophe, and you spelled “superfluous” incorrectly.
@20 Grammar Nazi says:
I don’t claim to be perfect by any means but I don’t deliberately introduce lexicographical errors like using “embiggen” instead of “enlarge”
No, but you advertise yourself as a stickler for language details, and pepper your statements with typographical errors. Bit ironic, no?
@20 Grammar Nazi says:
My tag here is a slang term which I thought I’d already explained earlier – ‘nazi’ here having the humerous sense of perfectionist; one who insists on getting ‘aspect X’* right.
Sigh. Humorous.
@20 Grammar Nazi says:
Can you please, answer my point on the analogy between bad use of scientific terminology and your own bad use of English here?
That should be easy. This is a science blog, not an English lesson. No claims have been made to the latter. Scientific terminology is used correctly here, and if an error is made, it is fixed. If you’re getting caught up on the use of a funny, made-up word (that we all understand is meant as a joke), then you are completely missing the point of this site. Have you actually learned anything from Dr. Plait? Or are you just here to pick nits?
August 5th, 2009 at 2:13 pm
I like embiggen and have also been known to harbour warm thoughts towards biggify. Also, that is an amazingly beautiful image.
August 5th, 2009 at 2:19 pm
@ RL
Well, probably they had some old photo plates to compare the new one’s too. Probably it was recorded in old “scriptures” that the star suddenly brightened and faded and at some later time did the same again. And since the secondary star has an orbit of roughly the same time, it seems to be a sweet coincidence.
This is what I guess how they achieved their numbers….
Btw: These discussions with “Grammar N**i” are a little pedantic, aren’t they? They somehow remind me of Anaconda, … although in a different way.
) that the word “Nazi” is hardly comparable with perfectionism (although the Nazis were perfect in being bad….).
As a German I have to say (yes, we are almost drilled to say so
August 5th, 2009 at 2:33 pm
Dr. Plait — When one of the two stars explode, it will obviously end the life of the other star, correct? Also, how much is each star affected when they pass each other in orbit? You mentioned that they rip material off each other, so I’m curious to know what kind of destruction happens twice each century. Thanks in advance!
August 5th, 2009 at 2:38 pm
Thanks Becca! you were a of…enormous help
haha
August 5th, 2009 at 2:42 pm
@ NewEnglandBob, # 30
Are you having and “ebiggen” epilepsy?
August 5th, 2009 at 2:44 pm
can someone explain me why all the fuss about assigning some meaning to a combination of letters ?
August 5th, 2009 at 2:47 pm
Thanks to you Grammer Nazi, embiggen will now be added to my regular vocabulary. Sooner or later, you’ll get over your butthurt.
About the star – I am interested in the stellar classification of the companion star. Any further information?
August 5th, 2009 at 3:45 pm
B[e] stars are pretty weird objects… they rotate very fast, which distorts their shape, and they seem to be surrounded by discs that may well be produced by matter getting flung off the equator. Binaries where the secondary star gets close enough to interact with the disc can lead to fascinating effects. One of my favourite examples is SS 2883, whose companion is a pulsar (PSR B1259-63) in an eccentric orbit that crashes through the B[e] star disc twice per revolution, with energetic consequences.
August 5th, 2009 at 4:44 pm
Grammar Nazi, I’ll make you a deal: I’ll keep saying whatever I want however I want with whatever words I want, and you won’t complain any more and disrupt the conversation.
It’s a perfectly cromulent deal.
August 5th, 2009 at 5:03 pm
Embiggen is definitely the word. I just read the press release, the extreme close up view is embiggened 60000 times compared to the wide angle view.
Looking forward to the pictures from the next close encounter between those two.
August 5th, 2009 at 6:00 pm
[...] 50 Jahre. Verantwortlich ist vermutlich ein enger Begleiter des <a href=B[e]-Sterns, der schon Gegenstand der unterschiedlichsten Untersuchungsmethoden [...]
August 5th, 2009 at 6:12 pm
Great post BA:). Normally I have minimal interest in stellar evolution (it’s neat stuff, but it inexplicably bores me for some reason), but this is a cool case. Those stars are in a pretty wacky setup.
August 5th, 2009 at 6:31 pm
i love massive astropics
August 5th, 2009 at 7:56 pm
Way to hijack the conversation, Grammar Nazi. I, too, am a “Grammar Nazi”, but, and this may surprise you, it’s Phil’s blog.
Plus, I have this nifty key on my keyboard that lets me delete any misspellings I may accidently use.
August 5th, 2009 at 9:07 pm
Thanks Dr Flimmer. A 50 year cycle sounded like a long period to measure. I guess the observations go way back.
August 5th, 2009 at 11:04 pm
@ G Nazi #20,
Not to speak for Phil, but I think it’s clear that “enlarge” is just too dull for such an interesting blog. He’s always written with a certain humor and irreverence that most of us really enjoy. Also, this blog is not a democracy, and if it were, I’m pretty sure you’d be outvoted. Feel free to write in your preferred style and accept that Phil will write in his.
Incidentally, I understand your underlying point and I don’t use made-up words and I despise “text speak” in all its forms, but this is Phil’s blog so please don’t grudge him a joke just because you don’t think it’s funny.
PS. I see that we’ve been gently asked to lay off the grammar thread. I can do that.
August 5th, 2009 at 11:44 pm
Hey BA, why give ‘Grammar nazi’ all the attention for his Off Topic Pedantry while you ignore my On Topic Pedantry – & questions? I’m feeling neglected here!
@ 15. Robert Cumming Says:
…Plutonium: It’s all about the sort of emission lines the stars have. Be stars have allowed lines, B[e] stars have forbidden lines. And they all have square brackets in their names. The cognoscenti pronounce them B-bracket-e, if I remember right.
& also
@ 8. Kurtis W. Says:
Cool stuff, but one minor quibble. The “B” does not necessarily mean that the star will end its life as a supernovae; the majority of B-type main sequence stars will make white dwarfs. But B-type giants and supergiants, like this star, are massive enough to explode.
Plutonium, the [e] not only indicates emission lines, but that the emission lines are forbidden transitions, which are typically indicated with brackets. (See http://en.wikipedia.org/wiki/Forbidden_mechanism)
Thanks both of you – I didn’t know that & just thought it was ‘e’ for emission lines.
Nor did I realise this star was a giant either – which makes a bit of difference actually! Cheers!
@ 41. fizzyb Says:
… About the star – I am interested in the stellar classification of the companion star. Any further information?
I second that request.
I’d also really love to have my questions (posts # 2, #7 & #16) answered if possible please :
1. Could we have exact spectral types for these binary stars & their masses? (Pref. in solar masses.)
2. How will these stars evolve – will one or both components go supernova?
3. Does the Be classification make this binary system a shell star – or stars?
4. Are the stars close enough to exchange mass and thus create another Algol-like situation where one star gains mass from the other and alters or even prevents its evolution?
5. What magnitude is this pair? Is this star visible with unaided eyesight, binoculars or telescope?
Anybody please care to answer?
@ 37. Evan Says:
Dr. Plait — When one of the two stars explode, it will obviously end the life of the other star, correct?
Not exactly I’m afraid. I’m not 100 % sure myself & feel free to correct me if I’m wrong but I think the secondary star usually survives – at least at first.
Sometimes you get a “black widow” pulsar situation where the binary companion to a supernova is left orbiting a neutron star or Black Hole which then steals matter from the surviving star, accretes it in a hot disk and emits radiation that then destroys the companion as it spins the neutron star up into a millisecond variety pulsar.
Other times, you get “runaway stars” like AE Aurigae, Mu Columbae & 57 Arietis which were ejected from their orginal “homes” by their companions going supernova (SN) – at least according to one theory on their origin.
Finally, sometimes you get stars left that are still orbiting their “dead” SN companions like happened with Cygnus X1 (the first stellar-mass black hole ever discovered) & SS 43 (I think?) and Scorpius X-1 all being cases of star systems with a supergiant star and black hole or neutron star pair.
Hope that helps.
August 6th, 2009 at 12:19 am
I thought I posted something here last night but maybe it went astray. Anyway, I did some checking, and this star has a visual magnitude of 9.1 so it should be an easy object for backyard observers. Also since it’s in the HD catalogue it must have been known for nearly a century, but the earliest reference to it as an “interesting” star that I could find was an ApJ article on B[e] stars from 1933.
August 6th, 2009 at 12:31 am
@ 52 csrster : Thx for answering qu. 5 then!
Can you help answer any of the other 4 too, please?
——
PS. That’s odd. My post restating my questions above still says “awaiting moderation” at the top but crster has just answered one of the qu. I just asked in it! Mind you I did ask the same qu. in post 2,7 &^ 16 also.
Can other folks see my post 52 there & its revised five questions or not?
(Puzzled. Not sure why its in moderation either unless its for the quoted link?)
For the record the five questions I asked were :
@ 41. fizzyb Says:
… About the star – I am interested in the stellar classification of the companion star. Any further information?
I second that request.
I’d also really love to have my questions (posts # 2, #7 & #16) answered if possible please :
1. Could we have exact spectral types for these binary stars & their masses? (Pref. in solar masses.)
2. How will these stars evolve – will one or both components go supernova?
3. Does the Be classification make this binary system a shell star – or stars?
4. Are the stars close enough to exchange mass and thus create another Algol-like situation where one star gains mass from the other and alters or even prevents its evolution?
5. What magnitude is this pair? Is this star visible with unaided eyesight, binoculars or telescope?
Anybody please care to answer?
I’ll wait & see what happens before – maybe – reposting the rest again. Except to say thanks again to # 8. Kurtis W. & # 15. Robert Cumming for their replies.
August 6th, 2009 at 1:22 am
so, any numbers one when we might get to see this little guy go nova? Is it Dec (somethinsomethin), 2012?
August 6th, 2009 at 2:13 am
Plutonium being from Pluto: the answers to most of your questions is that we don’t know. For a start, the infrared observations used to detect the individual binary components are not seeing the stars themselves but instead circumstellar material in orbit around them. Secondly the distance (and hence absolute luminosity) of the system is highly uncertain. Thirdly the binary orbit is substantially longer than the period over which the individual binary components have been observed. They are currently widely separated (by at least 50 AU if the highly uncertain distance is taken to be 1.5 kiloparsecs), but if the orbit is highly eccentric they could pass very close to each other.
August 6th, 2009 at 4:34 am
Sorry to complain and disrupt the conversation, but language deprived persons like GN makes me really sad. Language is communication, and there are many dimensions to that. GN adding uncommunicative noise is only the start of it.
As several people points out, if humor, personality and the essential adaptive mechanism of language is removed or curbed by unnecessary and dogmatic rules that hinder communication and natural language evolution, it’s a problem. These nutters want to kill language and so by continuance communication by perverting these processes.
It also shows how those perpetrating such irrational acts aren’t actually interested in language as such, or the unnatural ideal of its “perfection”, but in control. “Grammar Nazis” in general are small and scared people. [/rant]
Oh, and I’m sure that my often expressed inability to use grammar has nothing to do with it.
(For reasons not interesting here, I learned language by “monkey see, monkey do”, if it’s not obvious. By now I’m quite unable to revert. “Verb” you say? Hmm, wasn’t that something about someone doing something or another? … I really can’t tell.)
[Btw, some pedants have a genuine knowledge and interest in language. Too bad they express it by so unproductive and destructive means.
And then we have the large group of people who actually likes to help people with genuine problems of communication, for example persistent errors that makes their texts less legible. They don't complain, they don't point fingers (in the wrong directions); they help!]
August 6th, 2009 at 5:56 am
According to Wikipedia, “embiggen” was first used in English in 1884:
It has been in regular use for over a decade; Phil uses it in a perfectly cromulent manner. And besides which, every word started out as made-up, no?
But back to astronomy. What I’d like to know is what the sky would look like from a planet orbiting that star (OK, maybe not a planet, which wouldn’t have formed in the first place, but from somewhere inside that amazing cloud.)
August 6th, 2009 at 8:41 am
Huzzah, Grammar Nazi! Forsooth, thou are rightwise in thine wrath against the lexiconical horreur that moderne worold hath wrought! Vary, the linguaticum must not. Verily, in thou, strong, the force.
n0W k4lm D0wn, 93T 0V3r j00RS3Lf, 4nd h4v3 4 m4rt1N1.
5e.-10|_|5L`/, D|_|DE. <|-|1|_|_.
August 6th, 2009 at 9:29 am
Quiet Desperation @ 58
I was right with you until that last line when you decromulentified yourself.
I was going to kindly request a translation to standard, ASCII-based English text, but after a minute of staring blankly, the pattern started to reconstitute its cromulenticity.
I can see the matrix!
August 6th, 2009 at 10:18 am
@ 55. andy Says:
Plutonium being from Pluto: the answers to most of your questions is that we don’t know.
I was hoping somebody here *might* know which is why I was asking – but thanks anyway.
Glad to see my whole post is finally there.
Could we at least get the spectral type even approx. for the companion star & ballpark stellar masses? Please?
August 6th, 2009 at 4:28 pm
Could we at least get the spectral type even approx. for the companion star & ballpark stellar masses? Please?
Answer is basically no. We don’t have enough knowledge of the system at present. The uncertainty in the distance (this system has not been measured by the Hipparcos probe) means we cannot tell whether the primary is a giant or a supergiant: this would have substantial implications for estimations of the stellar mass. Neither star was directly detected by the observations that resolved the binary system, only the radiation from the circumstellar matter, so assigning spectral type is essentially impossible at this point, and there basically isn’t anything that could be input into the stellar mass models. In addition, the secondary disc was not resolved, which makes it even harder to constrain its nature. In fact, the nature of the interferometry means there is a 180 degree degeneracy in the position angle of the binary: that is, we don’t know whether the northern or the southern component is the primary!
I suggest you read through the link to the paper that Phil Plait provided in his posting, as it goes into how the observations were carried out and what can be concluded from them in detail.
August 6th, 2009 at 7:45 pm
This post got some exposure at Caltech’s astro-ph coffee this morning
Someone brought it up, and we read through the post (and talked about this blog!) before actually getting on to the paper, lol.