Alpha Persei
From Wikipedia, the free encyclopedia
| Observation data Epoch J2000 |
|
|---|---|
| Constellation (pronunciation) |
Perseus |
| Right ascension | 03h 24m 19.4s |
| Declination | +49° 51′ 40″ |
| Apparent magnitude (V) | 1.79 |
| Characteristics | |
| Spectral type | F5 Ib |
| U-B color index | 0.37 |
| B-V color index | 0.48 |
| Variable type | ? |
| Astrometry | |
| Radial velocity (Rv) | -2 km/s |
| Proper motion (μ) | RA: 24.11 mas/yr Dec.: -26.01 mas/yr |
| Parallax (π) | 5.51 ± 0.66 mas |
| Distance | approx. 590 ly (approx. 180 pc) |
| Absolute magnitude (MV) | -4.50 |
| Details | |
| Mass | 11 M☉ |
| Radius | 56 R☉ |
| Luminosity | 5,400 L☉ |
| Temperature | 6,600 K |
| Metallicity | ? |
| Rotation | 18 km/s. |
| Age | ? years |
| Other designations | |
Alpha Persei (α Per) is the brightest star in the constellation of Perseus, just outshining the constellation's best known star Algol. It also bears the traditional names of Mirfak or Algenib. A yellow-white supergiant, it lies around 590 light years from Earth and is a member of a cluster of stars known as the Alpha Persei Cluster.
Contents |
[edit] Physical properties
Mirfak is a yellow-white supergiant of spectral type F5 Ib with an apparent brightness of 1.79 m lying at a distance of around 590 light-years, or 180 parsecs, from Earth. With an absolute magnitude of -4.50, its luminosity is 5,000 times and its diameter is 62 times that of our Sun. It has a similar spectrum to Procyon, though the latter star is much less luminous. This difference is highlighted in their spectral designation under the Yerkes spectral classification, published in 1943, where stars are ranked on luminosity as well as spectral typing. Procyon is thus F5 IV.[1]
It lies in the middle of a cluster of stars known as the Alpha Persei Cluster, or Melotte 20 which is easily visible in binoculars and includes many of the fainter stars of Perseus.
In the Hertzsprung-Russell Diagram, Mirfak lies very close to the region in which Cepheid variables are found. It is thus useful in the study of these stars, which are extremely important standard candles.
[edit] Visibility
A fairly bright star of the second magnitude, Mirfak is circumpolar when viewed from the latitude of New York.[2]
[edit] Etymology and cultural significance
The names Mirfak and Algenib are Arabic in origin. The former, meaning 'Elbow' and also written Mirphak, Marfak or Mirzac, comes from the Arabic Marfiķ al Thurayya, while the latter, also spelt Algeneb, Elgenab, Gęnib, Chenib or Alchemb, is derived from الجنب al-janb, or الجانب al-jānib, 'the flank' or 'side'.[2] Gamma Pegasi also bears the name Algenib.
It forms part of Tien Yuen, the Heavenly Enclosure, in traditional Chinese astronomy.[2]
Hinali'i is the name of the star in Native Hawaiian astronomy. The name of the star is meant to commemorate a great tsunami and mark the beginning of the migration of Maui. According to some Hawaiian folklore, Hinali'i is the point of separation between the earth and the sky that happened during the creation of the Milky Way.[3]
The star Hinali'i first rises in the east in the month of August and follows the path of another star, probably α, β and γ Cassiopeiae.
[edit] Footnotes
- ^ Ramanamurthy G (2007). Biographical Dictionary of Great Astronomers. Sura Books, p167. ISBN 817478697X.
- ^ a b c Allen, Richard Hinckley (1963). Star Names: Their Lore and Meaning (revised edition). Dover, p332-33. ISBN 0-486-21079-0.
- ^ Malama Maunakea Astronomy
[edit] External links
 |
This astronomy related article is a stub. You can help Wikipedia by expanding it. |
