Yup, Beetlejuice is indeed a strange place! But remember, that is an artists impression.
SpeedFreek":2nqr9veq said:Yup, Beetlejuice is indeed a strange place! But remember, that is an artists impression.
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.
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.
hansolo0":1eemb4d0 said:"a million full moons in the sky" and that "night would turn into day" here on earth for at least a few weeks.
hansolo0":1gf2dwcd said: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...
Just for the record: Betelgeuse 'shrinking' is a loss of volume, not mass. At least not yethansolo0":3jvyt8od said: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....