Betelgeuse | has spectral type M2 Iab | ![has source: Hopkins, J. 1976 Glossary of Astronomy and Astrophysics, University of Chicago Press, 2001-09-27 09:31:44.0 has source: Hopkins, J. 1976 Glossary of Astronomy and Astrophysics, University of Chicago Press, 2001-09-27 09:31:44.0](facet.gif) |
has distance 500 pc | ![has source: Hopkins, J. 1976 Glossary of Astronomy and Astrophysics, University of Chicago Press, 2001-09-27 09:31:44.0 has source: Hopkins, J. 1976 Glossary of Astronomy and Astrophysics, University of Chicago Press, 2001-09-27 09:31:44.0](facet.gif) |
has synonym alpha Ori | ![has source: Hopkins, J. 1976 Glossary of Astronomy and Astrophysics, University of Chicago Press, 2001-09-27 09:31:44.0 has source: Hopkins, J. 1976 Glossary of Astronomy and Astrophysics, University of Chicago Press, 2001-09-27 09:31:44.0](facet.gif) |
has image ![](http://oposite.stsci.edu/pubinfo/PR/96/04/Thumb.gif) | ![has URL: http://oposite.stsci.edu/pubinfo/PR/96/04.html, 2001-09-27 09:31:44.0 has URL: http://oposite.stsci.edu/pubinfo/PR/96/04.html, 2001-09-27 09:31:44.0](facet.gif) |
has definition A red supergiant star in the constellation Orion and the brightest red supergiant in Earth's sky. | ![has source: Croswell, K. 1995 The Alchemy of the Heavens, Anchor Books, 2001-09-27 09:31:44.0 has source: Croswell, K. 1995 The Alchemy of the Heavens, Anchor Books, 2001-09-27 09:31:44.0](facet.gif) |
has definition A red semiregular variable supergiant. Betelgeuse is also a strong infrared emitter - at 2 µ the brightest in the sky. | ![has source: Hopkins, J. 1976 Glossary of Astronomy and Astrophysics, University of Chicago Press, 2001-09-27 09:31:44.0 has source: Hopkins, J. 1976 Glossary of Astronomy and Astrophysics, University of Chicago Press, 2001-09-27 09:31:44.0](facet.gif) |
is an instance of red supergiant | ![2001-09-27 09:31:44.0 2001-09-27 09:31:44.0](facet.gif) |
is an instance of semiregular variable | ![2001-09-27 09:31:44.0 2001-09-27 09:31:44.0](facet.gif) |
semiregular variable | has amplitude variable | ![2001-09-27 09:30:39.0 2001-09-27 09:30:39.0](facet.gif) |
supergiant | has luminosity class I | ![2001-09-27 09:30:50.0 2001-09-27 09:30:50.0](facet.gif) |
variable | has name designated with - R, S, T, U, V, W, X, Y, or Z and the genitive of the latin constellation name
- RR, RS, RT, RU, RV, RW, RX, RY, or RZ and the genitive of the latin constellation name when the single letter designations are exhausted
- AA...AZ, BB...BZ, etc. (omitting J), which ends with QQ...QZ and the genitive of the latin constellation namewhen the RR...RZ designations are exhausted
- V 335, V 336, etc., when the double letter designations are exhausted
| ![2001-09-27 09:30:34.0 2001-09-27 09:30:34.0](facet.gif) |
has observational problem some difficulty in distinguishing between various kinds | ![2001-09-27 09:30:34.0 2001-09-27 09:30:34.0](facet.gif) |
has observable variation time scale within a period of decades | ![has URL: http://www.aavso.org, 2001-09-27 09:30:34.0 has URL: http://www.aavso.org, 2001-09-27 09:30:34.0](facet.gif) |
has light curve | ![2001-09-27 09:30:34.0 2001-09-27 09:30:34.0](facet.gif) |
has optical brightness variation 0.2 magnitudes or greater | ![2001-09-27 09:30:34.0 2001-09-27 09:30:34.0](facet.gif) |
star | has star surface temperature | ![2001-09-27 09:30:25.0 2001-09-27 09:30:25.0](facet.gif) |
has V magnitude | ![2001-09-27 09:30:25.0 2001-09-27 09:30:25.0](facet.gif) |
has B magnitude | ![2001-09-27 09:30:25.0 2001-09-27 09:30:25.0](facet.gif) |
has U magnitude | ![2001-09-27 09:30:25.0 2001-09-27 09:30:25.0](facet.gif) |
has position on celestial sphere from the point of view of Earth | ![2001-09-27 09:30:25.0 2001-09-27 09:30:25.0](facet.gif) |
has parallax from the point of view of Earth's orbit | ![2001-09-27 09:30:25.0 2001-09-27 09:30:25.0](facet.gif) |
has proper motion | ![2001-09-27 09:30:24.0 2001-09-27 09:30:24.0](facet.gif) |
has radiation at surface which is diffused out from the hotter core | ![2001-09-27 09:30:24.0 2001-09-27 09:30:24.0](facet.gif) |
has energy source gravitational contraction and or fusion | ![2001-09-27 09:30:24.0 2001-09-27 09:30:24.0](facet.gif) |
has energy production which takes place primarily within the core | ![2001-09-27 09:30:24.0 2001-09-27 09:30:24.0](facet.gif) |
has surface density which depends on luminosity class | ![2001-09-27 09:30:24.0 2001-09-27 09:30:24.0](facet.gif) |
has surface temperature greater than 1000 Kelvin | ![2001-09-27 09:30:24.0 2001-09-27 09:30:24.0](facet.gif) |
has apparent magnitude | ![2001-09-27 09:30:25.0 2001-09-27 09:30:25.0](facet.gif) |
has absolute magnitude | ![2001-09-27 09:30:25.0 2001-09-27 09:30:25.0](facet.gif) |
has age | ![2001-09-27 09:30:25.0 2001-09-27 09:30:25.0](facet.gif) |
has catalog star catalog | ![2001-09-27 09:30:25.0 2001-09-27 09:30:25.0](facet.gif) |
has material hydrogen, helium | ![2001-09-27 09:30:24.0 2001-09-27 09:30:24.0](facet.gif) |
has velocity determined from proper motion and radial velocity | ![2001-09-27 09:30:25.0 2001-09-27 09:30:25.0](facet.gif) |
has mass greater than 0.08 the sun's mass | ![2001-09-27 09:30:24.0 2001-09-27 09:30:24.0](facet.gif) |
celestial body | has spectra | ![2001-09-27 09:30:09.0 2001-09-27 09:30:09.0](facet.gif) |
physical object | has location or center of gravity | ![2001-09-27 09:27:27.0 2001-09-27 09:27:27.0](facet.gif) |
has angular momentum | ![2001-09-27 09:27:27.0 2001-09-27 09:27:27.0](facet.gif) |
has momentum | ![2001-09-27 09:27:27.0 2001-09-27 09:27:27.0](facet.gif) |
has temperature | ![2001-09-27 09:27:27.0 2001-09-27 09:27:27.0](facet.gif) |
has volume | ![2001-09-27 09:27:27.0 2001-09-27 09:27:27.0](facet.gif) |
has extent | ![2001-09-27 09:27:27.0 2001-09-27 09:27:27.0](facet.gif) |