15 Eridani

{{short description|Star in the constellation Eridanus}}

{{Starbox begin}}

{{Starbox observe

| epoch=J2000

| constell=Eridanus

| ra={{RA|03|18|22.10504}}{{cite journal|title=Validation of the new Hipparcos reduction|url=http://www.aanda.org/index.php?option=com_article&access=bibcode&Itemid=129&bibcode=2007A%2526A...474..653VFUL|author=van Leeuwen, F.|display-authors=etal|journal=Astronomy and Astrophysics|volume=474|issue=2|pages=653–664|date=2007|arxiv=0708.1752|bibcode=2007A&A...474..653V|doi=10.1051/0004-6361:20078357|s2cid = 18759600}}

| dec={{DEC|-22|30|40.0191}}

| appmag_v=4.875{{cite journal|title=The Tycho-2 catalogue of the 2.5 million brightest stars|author=Høg, E.|display-authors=etal|date=2000|journal=Astronomy and Astrophysics|volume=355|pages=L27–L30|bibcode=2000A&A...355L..27H}}
(6.57 / 5.32)

}}

{{Starbox character

| type=red clump

| class=K0III{{cite journal|bibcode=1988mcts.book.....H|title=Michigan Catalogue of Two-dimensional Spectral Types for the HD Stars. Volume 4, Declinations -26°.0 to -12°.0.|journal=Michigan Catalogue of Two-dimensional Spectral Types for the HD Stars|volume=4|author1=Houk, N.|author2=Smith-Moore, M.|year=1988}}

| b-v=+0.90{{cite journal|title=UBVRIJKL Photometry of the Bright Stars|author1=Johnson, H. L.|journal=Communications of the Lunar and Planetary Laboratory|volume=4|pages=99|date=1966|bibcode=1966CoLPL...4...99J}}

}}

{{Starbox astrometry

| radial_v={{Val|23.90|0.5}}{{cite journal|title=Astrophysical supplements to the ASCC-2.5: Ia. Radial velocities of ~55000 stars and mean radial velocities of 516 Galactic open clusters and associations|author=Kharchenko, N. V.|display-authors=etal|journal=Astronomische Nachrichten|volume=328|issue=9|page=889|date=2007|bibcode=2007AN....328..889K|doi=10.1002/asna.200710776|arxiv=0705.0878|s2cid=119323941}}

| prop_mo_ra=13.08

| prop_mo_dec=13.33

| parallax=12.77

| p_error=1.17

| parallax_footnote=

| absmag_v=+0.85{{citation

| last1=Ammler-von Eiff | first1=Matthias | last2=Reiners | first2=Ansgar

| title=New measurements of rotation and differential rotation in A-F stars: are there two populations of differentially rotating stars?

| journal=Astronomy & Astrophysics | arxiv=1204.2459

| volume=542 | page=A116 | date=June 2012 | postscript=.

| doi=10.1051/0004-6361/201118724 | bibcode=2012A&A...542A.116A | s2cid=53666672 }}

}}

{{Starbox orbit

| reference={{cite web|url=http://www.usno.navy.mil/USNO/astrometry/optical-IR-prod/wds/orb6|title=Sixth Catalog of Orbits of Visual Binary Stars|publisher=United States Naval Observatory|accessdate=11 August 2017|archive-date=1 August 2017|archive-url=https://web.archive.org/web/20170801102553/http://www.usno.navy.mil/USNO/astrometry/optical-IR-prod/wds/orb6|url-status=dead}}

| period=118.16

| axis=0.340

| inclination=66.6

| node=271.6

| periastron=1934.24

| eccentricity=0.030

| periarg=333.5

}}

{{Starbox detail

| source=

| component1 = 15 Eri A

| mass=2.32{{cite journal | title=Abundances in the Local Region. I. G and K Giants | last1=Luck | first1=R. Earle | journal=Astronomical Journal | volume=150 | issue=3 | at=88 | year=2015 | arxiv=1507.01466 | bibcode=2015AJ....150...88L | doi=10.1088/0004-6256/150/3/88 | s2cid=118505114 }}

| radius=

| temperature={{Val|4960|31|fmt=commas}}

| luminosity=72.4

| gravity=

| metal_fe=

| rotational_velocity={{Val|4.5|0.2}}

| age_gyr=1.44

}}

{{Starbox catalog

| names={{odlist | F=15 Eri | CD=−22°1146 | HD=20610 | HIP=15382 | HR=994 | SAO=168452 | WDS=J03184-2231 }}

}}

{{Starbox reference

| Simbad=15+Eri

}}

{{Starbox end}}

15 Eridani is a binary star system in the equatorial constellation of Eridanus. It is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 4.875. Based upon parallax measurements, the system is located around 260 light years away from the Sun. It is moving further from the Earth with a heliocentric radial velocity of 24 km/s.

This system has an orbital period of 118.16 years with an eccentricity of 0.030 and a semimajor axis of {{Val|0.340|ul=arcsecond}}. The primary member, designated component A, is a magnitude 5.32{{cite journal | last1=Eggleton | first1=P. P. | last2=Tokovinin | first2=A. A. | title=A catalogue of multiplicity among bright stellar systems | journal=Monthly Notices of the Royal Astronomical Society | volume=389 | issue=2 | pages=869–879 | date=September 2008 | doi=10.1111/j.1365-2966.2008.13596.x | doi-access=free | bibcode=2008MNRAS.389..869E | arxiv=0806.2878 | s2cid=14878976 }} giant star with a stellar classification of K0 III. It is a red clump giant,{{citation | last1=Alves | first1=David R. | title=K-Band Calibration of the Red Clump Luminosity | journal=The Astrophysical Journal | volume=539 | issue=2 | pages=732–741 | date=August 2000 | doi=10.1086/309278 | bibcode=2000ApJ...539..732A | arxiv=astro-ph/0003329 | s2cid=16673121 }} which means it is on the horizontal branch and is generating energy through helium fusion at its core. This star has 1.44 billion years old with 2.32 times the mass of the Sun. It is radiating 72.4 times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 4,960 K. The companion, component B, has a magnitude of 6.57.