Epsilon Leonis
 Algenubi is the ε star in the lion's head. |
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| Observation data Epoch J2000 Equinox J2000 |
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|---|---|
| Constellation | Leo |
| Right ascension | 09h 45m 51.0730s[1] |
| Declination | 23° 46′ 27.317″[1] |
| Apparent magnitude (V) | 2.975 [1] |
| Characteristics | |
| Spectral type | G1II [1] |
| U−B color index | 0.39 [1] |
| B−V color index | 0.82 [1] |
| Variable type | Cepheid |
| Astrometry | |
| Radial velocity (Rv) | 4.3 [1] km/s |
| Proper motion (μ) | RA: -46.09 [1] mas/yr Dec.: -9.57 [1] mas/yr |
| Parallax (π) | 13.01 ± 0.88[1] mas |
| Distance | 250 ± 20 ly (77 ± 5 pc) |
| Absolute magnitude (MV) | -1.45 |
| Details | |
| Mass | 4 [2] M☉ |
| Radius | 23[2] R☉ |
| Luminosity | 360 [2] L☉ |
| Temperature | 5,300 [2] K |
| Metallicity | 0.02 Fe/H[3] |
| Rotation | 5.7 km/s [2] |
| Age | 1.65×108 [2] years |
| Other designations | |
| Database references | |
| SIMBAD | data |
Epsilon Leonis (ε Leo, ε Leonis) is the fifth brightest star in the constellation Leo, consistent with its Bayer designation Epsilon. The star has the traditional names Ras Elased (Australis), Asad Australis and Algenubi, all of which derive from the Arabic رأس الأسد الجنوبي rās al-’asad al-janūbī, which means "the southern (star) of the lion's head"; australis is Latin for "southern".
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[edit] Properties
Epsilon Leonis is a G class star similar to the Sun. Its stellar classification is G1 II. However, it is much larger and brighter than the Sun with a luminosity 360 times and a diameter 23 times solar.[2] Consequently, its absolute magnitude is actually -1.46, making it one of the more luminous stars in the constellation, significantly more than its alpha star, Regulus. Algenubi's apparent brightness, though, is only 2.975.[1] Given its distance of about 250 light years from Earth, the star is more than 3 times the distance from us than Regulus.
Algenubi exhibits the characteristics of a Cepheid variable, changing by approximately 1/10 magnitude every few days.[2]
[edit] See also
- Lists of stars in the constellation Leo
- Class G Stars
- Variable star
- Algenubi in fiction
[edit] References
- ^ a b c d e f g h i j k "SIMBAD query result: eps Leo -- Variable Star". Centre de Données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-id?Ident=eps+leo&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id. Retrieved 2010-05-10.
- ^ a b c d e f g h Professor James B. (Jim) Kaler. "ALGENUBI (Epsilon Leonis)". University of Illinois. http://stars.astro.illinois.edu/sow/algenubi.html. Retrieved 2010-05-10.
- ^ Soubiran, C.; Bienaymé, O.; Mishenina, T. V.; Kovtyukh, V. V. (2008). "Vertical distribution of Galactic disk stars. IV. AMR and AVR from clump giants" (PDF). Astronomy and Astrophysics 480: 91–101. Bibcode 2008A&A...480...91S. doi:10.1051/0004-6361:20078788. http://cds.aanda.org/index.php?option=article&access=bibcode&bibcode=2008A%2526A...480...91S. Retrieved 2010-05-11.
[edit] External links
- Jim Kaler's Stars:Algenubi
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