Epsilon Leonis

{{Starbox image

| image=

{{Location mark

|image=Leo constellation map.svg|alt=|float=center|width=280

|label=|position=right

|mark=Red circle.svg|mark_width=10|mark_link=ε Leonis

|x=891|y=267

}}

|caption=Location of ε Leonis (circled)

}}

{{Starbox observe

| epoch = J2000

| ra = {{RA|09|45|51.07330}}

| dec = {{DEC|+23|46|27.3208}}

| appmag_v = 2.98

| constell = Leo

}}

{{Starbox character

| class = G1 II

| b-v = +0.808

| u-b = +0.47

| variable = suspected{{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|last1=Samus|first1=N. N.|last2=Durlevich|first2=O. V.|year=2009}}

}}

{{Starbox astrometry

| radial_v = {{nowrap|4.86 ± 0.33}}

| prop_mo_ra = –45.61

| prop_mo_dec = –9.21

| parallax = 13.22

| p_error = 0.15

| parallax_footnote =

| absmag_v = –1.49

}}

{{Starbox detail

| mass = {{val|3.71|0.04}}

| radius = {{val|21.03|0.31|0.32}}

| gravity = {{val|2.36|0.05}}

| luminosity = {{val|282|13}}

| temperature = {{val|5314|17|fmt=commas}}

| metal_fe = {{val|-0.03|0.11}}

| age_myr = {{val|210|0}}

| rotational_velocity = 8.1

}}

{{Starbox catalog

| names = Algenubi, Ras Elased Australis, ε Leo, 17 Leo, BD+24°2129, FK5 367, GC 13443, HD 84441, HIP 47908, HR 3873, SAO 81004

}}

{{Starbox reference

| Simbad=HD+84441

}}

Epsilon Leonis (ε Leo, ε Leonis) is the fifth-brightest star in the constellation Leo, consistent with its Bayer designation Epsilon. It is known as Algenubi or Ras Elased Australis. Both names mean "the southern star of the lion's head". Australis is Latin for "southern" and Genubi is Arabic for "south".

Properties

Epsilon Leonis has a stellar classification of G1 II, with the luminosity class of II indicating that, it has evolved into a bright giant. It is much larger and brighter than the Sun with a luminosity 282 times and a radius 21 times solar. Consequently, its absolute magnitude is actually –1.49, making it one of the more luminous stars in the constellation, significantly more than Regulus. Its apparent brightness, though, is only 2.98. 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.

Epsilon Leonis exhibits the characteristics of a Cepheid-like variable, changing by an amplitude of 0.3 magnitude every few days. It has around four times the mass of the Sun and a projected rotational velocity of {{nowrap|8.1 km s⁻¹}}. 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.

References

{{reflist|refs=

{{citation | first1=Floor | last1=van Leeuwen |date=November 2007 | title=Validation of the new Hipparcos reduction | volume=474 | issue=2 | pages=653–664 | bibcode=2007A&A...474..653V | arxiv=0708.1752v1 | doi=10.1051/0004-6361:20078357 | journal=Astronomy and Astrophysics | s2cid=18759600 }} Note: see VizieR catalogue [http://vizier.u-strasbg.fr/viz-bin/Cat?I/311 I/311].

{{Citation |last1=Soubiran |first1=C. |last2=Creevey |first2=O. L. |last3=Lagarde |first3=N. |last4=Brouillet |first4=N. |last5=Jofré |first5=P. |last6=Casamiquela |first6=L. |last7=Heiter |first7=U. |last8=Aguilera-Gómez |first8=C. |last9=Vitali |first9=S. |last10=Worley |first10=C. |last11=de Brito Silva |first11=D. |date=2024-02-01 |title=Gaia FGK benchmark stars: Fundamental Teff and log g of the third version |bibcode=2024A&A...682A.145S |journal=Astronomy and Astrophysics |volume=682 |pages=A145 |doi=10.1051/0004-6361/202347136 |arxiv=2310.11302 |issn=0004-6361}} [https://vizier.cds.unistra.fr/viz-bin/VizieR?-source=J/A%2BA/682/A145&HIP=HIP47908 Epsilon Leonis' database entry] at VizieR.

{{citation

| title=Fundamental Parameters of 87 Stars from the Navy Precision Optical Interferometer

| last1=Baines | first1=Ellyn K. | last2=Armstrong | first2=J. Thomas

| last3=Schmitt | first3=Henrique R. | last4=Zavala | first4=R. T.

| last5=Benson | first5=James A. | last6=Hutter | first6=Donald J.

| last7=Tycner | first7=Christopher | last8=Belle | first8=Gerard T. van

| display-authors=1 | journal=The Astronomical Journal

| volume=155 | at=30 | year=2018 | issue=1

| arxiv=1712.08109 | bibcode=2018AJ....155...30B

| doi=10.3847/1538-3881/aa9d8b | s2cid=119427037 | doi-access=free }}.

{{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 | doi-access=free }}

{{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 | page=99 | bibcode=1966CoLPL...4...99J }}

{{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 | access-date=2010-05-10 }}

{{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 | s2cid=16258166 }}

{{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}}

}}

Category:Leo (constellation)

Leonis, Epsilon

Algenubi

Leonis, 17

Category:Classical Cepheid variables

Category:G-type bright giants

047908

3873

084441

Category:Suspected variables

Category:Durchmusterung objects