Denebola (β Leo / β Leonis / Beta Leonis) is the second brightest star in the constellation Leo. In astronomy, an epoch is a moment in time for which celestial coordinates or orbital elements are specified. ... A Julian epoch is an epoch that is based on Julian years of exactly 365. ... Jump to: navigation, search This article is about the year 2000. ... Most stars are of nearly constant luminosity. ... In astronomy, stellar classification is a classification of stars based initially on photospheric temperature and its associated spectral characteristics, and subsequenly refined in terms of other characteristics. ... Right ascension (RA; symbol α: Greek letter alpha) is the astronomical term for one of the two coordinates of a point on the celestial sphere when using the equatorial coordinate system. ... In astronomy, declination (dec) is one of the two coordinates of the equatorial coordinate system, the other being either right ascension or hour angle. ... A light year, abbreviated ly, is the distance light travels in one year: roughly 9. ... Jump to: navigation, search The parsec (symbol pc) is a unit of length used in astronomy. ... The apparent magnitude (m) of a star, planet or other heavenly body is a measure of its apparent brightness; that is, the amount of light received from the object. ... (Redirected from 1 E30 kg) Categories: Orders of magnitude (mass) ... In astronomy, the solar mass is a unit of mass used to express the mass of stars and larger objects such as galaxies. ... To help compare distances at different orders of magnitude this page lists lengths starting at 1011 metres (100 million kilometres or 0. ... In astronomy, the solar radius is a unit of length used to express the size of stars and larger objects such as galaxies. ... In astronomy, absolute magnitude is the apparent magnitude, m, an object would have if it were at a standardized distance away. ... Jump to: navigation, search // In General Physics In general physics, luminosity (more properly called luminance) is the density of luminous intensity in a given direction. ... The solar luminosity is a unit of luminosity (power emitted in the form of photons) conventionally used by astronomers to give the luminosities of stars. ... The historical temperature record shows the fluctuations of the temperature of the atmosphere and the oceans throughout history, and in particular since 1850. ... Jump to: navigation, search The kelvin (symbol: K) is the SI unit of temperature, and is one of the seven SI base units. ... In astronomy, many stars are referred to simply by catalogue numbers. ... The Henry Draper Catalogue is an astronomy catalogue with astrometric and spectroscopic data about more than 225,000 stars. ... Beta (upper case Î’, lower case β) is the second letter of the Greek alphabet. ... Jump to: navigation, search Orion is a remarkable constellation, visible from most places on the globe (but not always the whole year long). ... Leo ( , Latin for lion) is a constellation of the zodiac. ...

Its name is shortened from Deneb Alased, from the Arabic phrase ذنب الاسد ðanab al-asad "tail of the lion", as it represents the lion's tail. (Deneb in Cygnus has a similar name origin.) Jump to: navigation, search Arabic (Arabic: العربية; transliterated: al-carabiyyah, less formally, عربي transliterated: carabÄ«) is the largest member of the Semitic branch of the Afro-Asiatic language family (classification: South Central Semitic) and is closely related to Hebrew and Aramaic. ... Cygnus, the constellation in which Deneb is located. ... Cygnus (Latin for swan) is a northern constellation. ...

Denebola is an A-type star, with a surface temperature of about 8500 K. It is about 36 light years distant from earth, and has a luminosity about twelve times that of the sun. Its apparent magnitude is 2.14. Denebola is a Delta Scuti type variable star, meaning its luminosity varies very slightly over a period of a few hours. Jump to: navigation, search The kelvin (symbol: K) is the SI unit of temperature, and is one of the seven SI base units. ... A light year, abbreviated ly, is the distance light travels in one year: roughly 9. ... The apparent magnitude (m) of a star, planet or other heavenly body is a measure of its apparent brightness; that is, the amount of light received from the object. ... A Delta Scuti variable is a variable star which exhibits variations in its luminosity due to both radial and non-radial pulsations of the stars surface. ... Most stars are of nearly constant luminosity. ...

Evidence for a dusty disk

Denebola shows a strong infrared excess, which means there must be a disk of cool dust in orbit around it. As our solar system is believed to have formed out of such a disk, Denebola and similar stars such as Vega and Beta Pictoris may be good candidate locations for extrasolar planets. The dust surrounding Denebola has a temperature of about 120 K. Unsuccessful attempts have been made to image the dust disk, implying that the disk is much smaller than that surrounding Beta Pictoris, which has been imaged frequently. Jump to: navigation, search Image of a small dog taken in mid-infrared (thermal) light (false color) Infrared (IR) radiation is electromagnetic radiation of a wavelength longer than visible light, but shorter than microwave radiation. ... Jump to: navigation, search Presentation of the solar system (not to scale) The solar system is the retinue of objects gravitationally bound to our Sun. ... Vega (α Lyr / α Lyrae / Alpha Lyrae) is the brightest star in the constellation Lyra, and the fifth brightest star in the sky. ... Beta Pictoris is the second brightest star in the constellation Pictor. ... Jump to: navigation, search Infrared image of the star GQ Lupi (A) orbited by a planet (b) at a distance of approximately 20 times the distance between Jupiter and our Sun. ...

Supercluster membership

Kinematic studies have shown that Denebola is part of a stellar association dubbed the IC 2391 supercluster. All the stars of this group share a roughly common motion through space, although they are not gravitationally bound. This implies that they were born in the same location, and perhaps initially formed an open cluster. Other stars in this association include Alpha Pictoris, Beta Canis Minoris and the open cluster IC 2391. In total more than sixty probable members of the group have been identified. In physics, kinematics is the branch of mechanics concerned with the motions of objects without being concerned with the forces that cause the motion. ... A stellar association is a very loose star cluster, looser than both open clusters and globular clusters. ... An open cluster is a group of up to a few thousand stars that were formed from the same giant molecular cloud, and are still gravitationally bound to each other. ... Gomeisa (β CMi) is a hot, B8-class main sequence star in the constellation of Canis Minor. ... An open cluster is a group of up to a few thousand stars that were formed from the same giant molecular cloud, and are still gravitationally bound to each other. ...

References

1. Cote J. (1987), B and A type stars with unexpectedly large colour excesses at IRAS wavelengths, Astronomy and Astrophysics (ISSN 0004-6361), v. 181, p. 77-84
2. Eggen O.J. (1991), The IC 2391 supercluster, Astronomical Journal (ISSN 0004-6256), v. 102, p. 2028-2040
3. Smith B.A., Fountain J.W., & Terrile R.J. (1992), An optical search for Beta Pictoris-like disks around nearby stars, Astronomy and Astrophysics (ISSN 0004-6361), v. 261, p. 499-502

External links

• SIMBAD data page
• Information page by Jim Kaler