Betelgeuse is one strange place

[SpeedFreek]

Yup, Beetlejuice is indeed a strange place! But remember, that is an artists impression.

 

[michaelmozina]

Yup, Beetlejuice is indeed a strange place! But remember, that is an artists impression.

I suppose I should have been more clear in my post, but I was talking about this image a bit further down the page rather than the artists rendering at the top of the article. I assume this image is an actual image, but feel free to correct me if I am mistaken:

I've been struggling to understand how Beetlejuice could shrink and yet retain a pretty constant light output over the past 15 years or so. That image makes me wonder if that star doesn't have a "thinner", more active, optically opaque photosphere, but it's "chromosphere" is perhaps less optically transparent to visible light than our chromosphere. Maybe that (pink) chromosphere emits more visible light and is more optically opaque than our chromosphere? Could this is due to the higher velocity of solar wind around a larger star? If that is the case, then perhaps that sun also experience high and low cycles of solar wind activity, and the chromosphere grows and shrinks depending on the wind conditions. All of this is pure speculation of course...

 

[MeteorWayne]

The more I read, the more I feel this should be merged into the Betelgeuse Shrinking thread. Expect that to happen soon....

Wayne

 

[CalliArcale]

Fine by me. ;-)

To michaelmozina, yes, that is an actual image of Betelgeuse. WOW!!!

 

[xXTheOneRavenXx]

Call me crazy, but I find when I stare at that image it gives the optical illusion of shrinking, lol. Had to put my cursor on the edge of the color just to be sure it wasn't, lol.

 

[MeteorWayne]

I decided to merge the other thread into this one

 

[michaelmozina]

I need some help with that image of Beetlejuice

I do not understand enough of the specifics of that last image to understand the physical relationships in this image as it relates to sizes of things. Is the diameter of Beetlejuice related to that white "core" we see in that last image, that 'pink', semi-opaque layer around the core, of something much smaller than either the core or the pink layer?

 

[harrycostas]

G'day from the land of ozzzzz

Here is a bit of info that may relate to the odd image in the previous post.

http://arxiv.org/abs/astro-ph/0211506
Chromospheric Dynamics of Betelgeuse from STIS Spectra

Authors: Alex Lobel
(Submitted on 22 Nov 2002)

Abstract: We present a high-resolution spectral analysis of Betelgeuse (M2 Iab). Between 1998 January and 1999 March four spatially resolved raster scans (this http URL) have been obtained with the STIS on the Hubble Space Telescope. The near-UV echelle spectra reveal double-peaked permitted emission lines of neutral and singly ionized metals, with self-absorbed line cores. We observe reversals in the intensity of both emission line components when scanning across the UV disk, for four unsaturated lines of Si I, Fe I, Al II], and Fe II. We model the Si I lam2516 resonance line with detailed non-LTE radiative transport calculations in spherical geometry, and constrain the mean velocity structure in the projected aperture area, for each scan position on the chromospheric disk. We infer the spatial velocity structure of Betelgeuse's extended chromosphere, which reveals localized upflows in the western front hemisphere in 1998 September, that expand further toward the eastern hemisphere in 1999 March. The spatial scans exhibit simultaneous up- and downflows across the lower chromosphere with mean velocities of ~2 km/s. We infer non-radial (or non-coherent) mass movements during certain phases of the stellar variability cycle from these subsonic flows. We present a discussion of constructing semi-empiric models for the chromosphere of this cool supergiant, and of its temporal variability.

 

[harrycostas]

G'day forgot this post

http://arxiv.org/abs/astro-ph/0606387
Dark Supergiant: Chandra's Limits on X-rays from Betelgeuse

Authors: Jennifer Posson-Brown, Vinay L. Kashyap, Deron O. Pease, Jeremy J. Drake
(Submitted on 15 Jun 2006 (v1), last revised 5 Dec 2007 (this version, v2))

Abstract: We have analyzed Chandra calibration observations of Betelgeuse (alpha Ori, M2Iab, m_V=0.58, 131 pc) obtained at the aimpoint locations of the HRC-I (8 ks), HRC-S (8 ks), and ACIS-I (5 ks). Betelgeuse is undetected in all the individual observations as well as cumulatively. We derive upper limits to the X-ray count rates and compute the corresponding X-ray flux and luminosity upper limits for coronal plasma that may potentially exist in the atmosphere of Betelgeuse over a range of temperatures, T=0.3-10 MK. We place a flux limit at the telescope of fx ~ 4x10^(-15) ergs s^(-1) cm^(-2) at T=1 MK. The upper limit is lowered by a factor of ~3 at higher temperatures, roughly an order of magnitude lower than that obtained previously. Assuming that the entire stellar surface is active, these fluxes correspond to a surface flux limit that ranges from 30-7000 ergs s^(-1) cm^(-2) at T=1 MK, to ~1 ergs s^(-1) cm^(-2) at higher temperatures, five orders of magnitude below the quiet Sun X-ray surface flux. We discuss the implications of our analysis in the context of models of a buried corona and a pervasive magnetic carpet. We rule out the existence of a solar-like corona on Betelgeuse, but cannot rule out the presence of low-level emission on the scale of coronal holes.

 

[dragon04]

I'd like to see similar hi-res images of other red supergiants such as Antares to use in comparison to what we're seeing here from A. Orionis.

 

[SpaceXFanMobius57]

Do you still think there might be a planet around Betuleguse. Like a planet as far out as sedna is to the sun. That would be an intense place!!

 

[prichardgs]

:idea: Well the star is a Red Giant with a diameter that would fit into Jupiter’s orbit around our sun, so maybe we are just observing the undulations between the force of gravity and the outward push of fusion. I would think the constant push and pull in a Red Giant would not allow for a very stable diameter…. My first post so be gental!

 

[MeteorWayne]

Welcome to Space.com!

Certainly you are right, in that a star is a constant battle between gravity and the energy from fusion at the core. At the Red Giant phase (which of course, someday our star will enter) the force from the center is unstable so there is fluctuation. I think the question that we are trying to answer with Betelgeuse is, how close to the "end" is it? We might find out, or it may be a few geneations down the road that get to watch the answer. In any case, we (the collective we, that is ) shall learn from it!

 

[prichardgs]

My thoughts are that a detailed look at the gas composition of the star coupled with analysis of its mass loss would be crucial in understanding how these big stars are dyeing…I have been able to find some information on this from the Max Planck Institute if you are interested. I think we have a few thousand years to go but if we collect the data…when it happens…we should have a better understanding of the life cycle of these giants…Thanks for the warm welcome!

 

[hansolo0]

Article in Latest Astronomy Magazine (Sept 09?)

There was an interesting article in Astronomy Magazine about how Astronomers are alarmed how Betelgeuse has shrank about 15% since 1993 I believe it was, and they aren't totally sure what is going on. It was stated that there was a possibility (although remote chance at best - may still take centuries to occur) that it could be headed toward going supernova. The brightness estimated to occur from this would be enough to light "a million full moons in the sky" and that "night would turn into day" here on earth for at least a few weeks. I don't recall the exact details on this but Betelgeuse's size was I think big enough to span from the center of our solar system to Saturn's orbit up until '93 , but now has shrank to Jupiter's.

I found a link to astronomy.com magazine online to the same(or similar) article and it talks about measuring the star's size in different light spectrums. It kind of confuses the issue on how just last year they measured it differently from a 1921 method (go figure) and got a bigger size , 3.7 au wide to 5.5 depending on which light spectrum is used , so how would they know if it really is shrinking then? Also, the online version doesn't seem to allude to supernova as much as I thought the hard copy version did, nor the quotes I mentioned above....hmm I'm going to have to reread it...

online version
http://www.astronomy.com/asy/default.aspx?c=a&id=8342

 

[michaelmozina]

Re: Article in Latest Astronomy Magazine (Sept 09?)

viewtopic.php?f=12&t=19223

You might want to read through this thread on that topic we had here awhile back.

 

[AlnitakAlnilamMintaka]

Re: Article in Latest Astronomy Magazine (Sept 09?)

You said that

"a million full moons in the sky" and that "night would turn into day" here on earth for at least a few weeks.

I don't recall it saying that. I get that magazine and remeber that article. I remember it saying that "it would be the light of a full moon pushed into a point of light" and that "it would blind you if you looked at it", for the previous reason. I remember the night into day. I know they said that. When I am home (I'm somewhere else now) I'll look that up.

 

[MeteorWayne]

Re: Article in Latest Astronomy Magazine (Sept 09?)

There was an interesting article in Astronomy Magazine about how Astronomers are alarmed how Betelgeuse has shrank about 15% since 1993 I believe it was, and they aren't totally sure what is going on. It was stated that there was a possibility (although remote chance at best - may still take centuries to occur) that it could be headed toward going supernova. The brightness estimated to occur from this would be enough to light "a million full moons in the sky" and that "night would turn into day" here on earth for at least a few weeks. I don't recall the exact details on this but Betelgeuse's size was I think big enough to span from the center of our solar system to Saturn's orbit up until '93 , but now has shrank to Jupiter's.

I found a link to astronomy.com magazine online to the same(or similar) article and it talks about measuring the star's size in different light spectrums. It kind of confuses the issue on how just last year they measured it differently from a 1921 method (go figure) and got a bigger size , 3.7 au wide to 5.5 depending on which light spectrum is used , so how would they know if it really is shrinking then? Also, the online version doesn't seem to allude to supernova as much as I thought the hard copy version did, nor the quotes I mentioned above....hmm I'm going to have to reread it...

online version
http://www.astronomy.com/asy/default.aspx?c=a&id=8342

I'm going to merge this question into the topic that michael linked to below. We've discussed it quite a bit. I'll try and pick up the Astronomy issue to read. Thanx

Wayne

 

[bdewoody]

Not that I wish anyone ill will (in case Betelgeuse has inhabited planets) but I sure would like to see it go supernova while I can still go outside to see it.

 

[xXTheOneRavenXx]

Re: Article in Latest Astronomy Magazine (Sept 09?)

By the sounds of it, if this "shrinking" continues on a steady course would I wrong in assuming that a supernova or whatever it is going to do is expected within the next couple hundred years? I mean if it shrank 15% since the 1921 reading.

 

[hansolo0]

No, I think it was 15% since '93, I was just talking about other measuring method's they used in '21 .

Betelgeuse is huge! half the size of our solar system, or 1000x the size of the sun! So , that is a lot of mass gone in only 16 years, but I will have to recheck the hard copy of all my facts again.. I can't find the reference to what issue the article is from online , but found it in a search online at astronomy.com (search for betelgeuse) but again, it wasn't the same as the quotes I mention previously in this thread.

It would be interesting too to me as well, if it did go supernova, and 'turn night into day' as it were, as long as we were in no danger. It might be a little like the end of 2010 (the movie , that is ).

I seem to recall reading that several thousand years ago some Chinese astronomer(s) reported this very thing happening to another star at the time and it briefly lit up the night, but I'm not sure how bright it was. Anyone else know about this?

 

[bdewoody]

Yeah, I think it was what we now refer to as the Crab Nebula.

 

[MeteorWayne]

I think I have a link to the original press release regarding Betelgeuse shrinking...in fact it's probably near the beginning of this thread. I'll see if I can find it.

Edit: Yes, see the first two posts in the thread

The Crab Nebula supernova occurred in 1054 AD (or CE), BTW

MW

 

[docm]

Betelgeuse is huge! half the size of our solar system, or 1000x the size of the sun! So , that is a lot of mass gone in only 16 years....

Just for the record: Betelgeuse 'shrinking' is a loss of volume, not mass. At least not yet

 

[MeteorWayne]

Well, your kind of right

All stars, especially at this stage of life are losing mass in their stellar wind... but certainly not 15% by any means.