| absmag_v = –1.49[12]
}}{{Starbox detail
| mass = 4.01[12]
| radius = 21[5]
| gravity = 2.2[5]
| luminosity = 288[5]
| temperature = 5,248[5]
| metal_fe = –0.28[5]
| age_myr = 162[12]
| rotational_velocity = 8.1[5]
}}{{Starbox catalog
| names = Algenubi, ε Leo, 17 Leo, BD +24°2129, FK5 367, GC 13443, HD 84441, HIP 47908, HR 3873, SAO 81004
}}{{Starbox reference
| Simbad=HD+84441
}}{{Starbox end}}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".{{citation needed|date=April 2017}}
Properties
Epsilon Leonis has a stellar classification of G1 II, with the luminosity class of II indicating that, at an age of {{nowrap|162 million years}},[12] it has evolved into a bright giant. It is much larger and brighter than the Sun with a luminosity 288 times and a radius 21 times solar.[5] Consequently, its absolute magnitude is actually –1.49,[12] 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 2.98.[3] Given its distance of about {{Convert|247|ly|pc|abbr=off|lk=on}}, the star is more than three times the distance from the Sun than Regulus. At this distance, the visual magnitude of Epsilon Leonis is reduced by 0.03 as a result of extinction caused by intervening gas and dust.[12]
Algenubi exhibits the characteristics of a Cepheid-like variable, changing by an amplitude of 0.3 magnitude every few days.[26][27] It has around four times the mass of the Sun and a projected rotational velocity of {{nowrap|8.1 km s−1}}.[5] Based upon its iron abundance, the metallicity of this star's outer atmosphere is only around 52% of the Sun's. That is, the abundance of elements other than hydrogen and helium is about half that in the Sun.[5]
See also
- Lists of stars in the constellation Leo
- Class G Stars
- Variable star
- Algenubi in fiction
References
1. ^{{cite journal|bibcode=2009yCat....102025S|title=VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)|journal=VizieR On-line Data Catalog: B/gcvs. Originally published in: 2009yCat....102025S|volume=1|display-authors=etal|author1=Samus|first1=N. N.|last2=Durlevich|first2=O. V.|year=2009}}
2. ^1 2 3 4 5 6 7 8 9 10 11 {{citation | display-authors=1 | last1=Massarotti | first1=Alessandro | last2=Latham | first2=David W. | last3=Stefanik | first3=Robert P. | last4=Fogel | first4=Jeffrey | title=Rotational and Radial Velocities for a Sample of 761 HIPPARCOS Giants and the Role of Binarity | journal=The Astronomical Journal | volume=135 | issue=1 | pages=209–231 |date=January 2008 | doi=10.1088/0004-6256/135/1/209 | bibcode=2008AJ....135..209M }}
3. ^1 2 3 {{citation | display-authors=1 | last1=Johnson | first1=H. L. | last2=Iriarte | first2=B. | last3=Mitchell | first3=R. I. | last4=Wisniewskj | first4=W. Z. | title=UBVRIJKL photometry of the bright stars | journal=Communications of the Lunar and Planetary Laboratory | volume=4 | issue=99 | year=1966 | bibcode=1966CoLPL...4...99J }}
4. ^1 {{cite simbad | title=eps Leo | accessdate=2010-05-10 }}
5. ^1 {{citation | title=ALGENUBI (Epsilon Leonis) | publisher=University of Illinois | work=Stars | first1=James B. | last1=Kaler | url=http://stars.astro.illinois.edu/sow/algenubi.html | accessdate=2010-05-10 }}
6. ^1 2 3 4 5 6 {{citation | last1=Takeda | first1=Yoichi | last2=Sato | first2=Bun'ei | last3=Murata | first3=Daisuke | title=Stellar parameters and elemental abundances of late-G giants | journal=Publications of the Astronomical Society of Japan | volume=60 | issue=4 | pages=781–802 |date=August 2008 | bibcode=2008PASJ...60..781T |arxiv = 0805.2434 |doi = 10.1093/pasj/60.4.781 }}
7. ^1 {{citation | last1=Andrievsky | first1=S. M. | title=BA II lines as luminosity indicators: s-Cepheids and non-variable supergiants | journal=Astronomische Nachrichten | volume=319 | issue=4 | pages=239–240 |date=July 1998 | bibcode=1998AN....319..239A | doi=10.1002/asna.2123190405}}
Note: see VizieR catalogue I/311.