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Post Info TOPIC: Rigel


L

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RE: Rigel
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Title: Asteroseismology of the Nearby SN-II Progenitor: Rigel Part I. The MOST High Precision Photometry and Radial Velocity Monitoring
Authors: Ehsan Moravveji, Edward F. Guinan, Matt Shultz, Michael H. Williamson, Andres Moya

Rigel (beta Ori, B8 Ia) is a nearby blue supergiant displaying alpha Cyg type variability, and is one of the nearest type-II supernova progenitors. As such it is an excellent test bed to study the internal structure of pre core-collapse stars. In this study, for the first time, we present 28 days of high precision MOST photometry and over 6 years of spectroscopic monitoring. We report nineteen significant pulsation modes of SNR>4.6 from radial velocities, with variability time scales ranging from 1.21 to 74.7 days, which are associated with high order low degree gravity modes. While the radial velocity variations show a degree of correlation with the flux changes, there is no clear interplay between the equivalent widths of different metallic and Halpha lines.

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L

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The Cassini spacecraft continues to profile the haze structure and opacity in Saturn's upper atmosphere with images like this, which captures Rigel, a star in Orion whose brightness is well-known, as it passes behind the planet.

PIA08238
Credit NASA/JPL

The extent to which the star's light is dimmed tells scientists about the sizes and amounts of the molecules and tiny particles that make up the atmospheric hazes.
The image was taken in visible red light with the Cassini spacecraft narrow-angle camera on June 30, 2004 at a distance of approximately 446,000 kilometres from Saturn. Image scale is 3 kilometres per pixel.

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L

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That is no Moon!
It is the supergiant star, Rigel, emerging from behind Saturn.
This image was captured by the Cassini spaceprobe in orbit around the planet.

PIA08187

The image was taken in visible green light with the Cassini spacecraft narrow-angle camera at a distance of approximately 663,000 kilometres from Saturn on April 28, 2006 .
The image scale is 4 kilometres per pixel.

Rigel (β Orionis) is a B8 Ia supergiant and the brightest star in the constellation Orion and the seventh brightest star in the sky, with visual magnitude 0.12. Rigel shines with approximately 40,000 times the luminosity of the Sun. It is far and away the most luminous star in our local region of the Milky Way. Although it has the Bayer designation "beta", it is almost always brighter than Betelgeuse (Alpha Orionis). It also has the alternative traditional names Algebar or Elgebar, but these are almost never used.
Rigel is between 700 and 900 light years away; Hipparcos' puts it at 773 light years (237 parsecs).
Rigel is a triple star. The main star is orbited by a binary system, Rigel B and C, which orbit one another closely at 28 AU and in turn orbit around Rigel as a unit, at a distance of about 2000 AU.

Position(2000): R.A. = 05h 14m 32.30s Dec. = −08 12' 06"

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