APOD: 2000 December 22 - Simulated Supergiant Star (original) (raw)

Astronomy Picture of the Day

Discover the cosmos!Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2000 December 22

Simulated Supergiant Star
Credit: B. Freytag, (Institute for Astronomy and Space Physics, Univ. Uppsala)

Explanation: Looking for that perfect holiday gift for an astronomer? Consider this "star in a box". Of course, the box is actually a computational box consisting of a three dimensional grid of points, and the star is a virtual one whosephysicalproperties and internaldynamicsare numerically simulated at the points on the grid. While computers and software capable of a totally realistic numerical simulation of a complete star don't presently exist, researchers have been making progress.This picture isa movie frame from a recent numerical simulation of asupergiant star with properties intended to approximate the real starBetelgeuse. The single frame shows large convection cells and bright spots mottling the virtual supergiant's surface.Simulation moviesshow these surface features changing substantially with time. Encouragingly,telescopic observations indicate that the surface of Betelgeuse does indeed have prominent large scale features and thewell-known star's brightness variations are detectable with the unaided eye. The real supergiantBetelgeuse is some 2,500 degrees cooler than, and 620 times the size of the Sun.

Tomorrow's picture: Summer Time

Authors & editors: Robert Nemiroff(MTU) &Jerry Bonnell (USRA)
NASA Technical Rep.: Jay Norris.Specific rights apply.
A service of: LHEA atNASA/GSFC
& Michigan Tech. U.