18 Aurigae

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

{{Starbox begin}}

{{Starbox observe

| epoch = J2000

| ra = {{RA|05|19|23.75342}}{{cite DR2|182009826266321792}}

| dec = {{DEC|+33|59|07.4035}}

| appmag_v = 6.489{{cite journal|title=The Tycho-2 catalogue of the 2.5 million brightest stars|author1=Høg, E.|display-authors=etal|date=2000|journal=Astronomy and Astrophysics|volume=355|pages=L27–L30|bibcode=2000A&A...355L..27H}}

| constell = Auriga

}}

{{Starbox character

| class = A7 V{{cite journal | doi=10.1086/110819 | title=A study of the bright stars. I. A catalogue of spectral classifications | journal=The Astronomical Journal | volume=74 | pages=375 | year=1969 | last1=Cowley | first1=A. | last2=Cowley | first2=C. | last3=Jaschek | first3=M. | last4=Jaschek | first4=C. | bibcode=1969AJ.....74..375C }}

| b-v = {{Val|+0.256|0.007}}

| u-b = +0.09{{cite journal | doi=10.1086/190359 | title=The galactic distribution of interstellar absorption as determined from the Celescope catalog of ultraviolet stellar observations and a new catalog of UBV, H-beta photoelectric observations | journal=The Astrophysical Journal Supplement Series | volume=30 | pages=97 | year=1976 | last1=Deutschman | first1=W. A. | last2=Davis | first2=R. J. | last3=Schild | first3=R. E. | bibcode=1976ApJS...30...97D | doi-access=free }}

| variable=

}}

{{Starbox astrometry

| radial_v={{Val|7.3|2}}{{cite journal|title=General catalogue of stellar radial velocities|journal=Washington|author=Wilson, Ralph Elmer|date=1953|bibcode=1953GCRV..C......0W}}

| prop_mo_ra = +28.497

| prop_mo_dec = −12.714

| parallax = 14.0275

| p_error = 0.0668

| parallax_footnote =

| absmag_v = 2.31{{cite journal | title=XHIP: An extended hipparcos compilation | last1=Anderson | first1=E. | last2=Francis | first2=Ch. | journal=Astronomy Letters | volume=38 | issue=5 | pages=331 | year=2012 | bibcode=2012AstL...38..331A | arxiv=1108.4971 | doi=10.1134/S1063773712050015 | s2cid=119257644 }}

}}

{{Starbox detail

| mass = {{Val|1.69|0.03}}{{cite journal | title=Rotational velocities of A-type stars. IV. Evolution of rotational velocities | last1=Zorec | first1=J. | last2=Royer | first2=F. | last3=Asplund | first3=Martin | last4=Cassisi | first4=Santi | last5=Ramirez | first5=Ivan | last6=Melendez | first6=Jorge | last7=Bensby | first7=Thomas | last8=Feltzing | first8=Sofia | display-authors=1 | journal=Astronomy and Astrophysics | volume=537 | pages=A120 | year=2012 | bibcode=2012A&A...537A.120Z | arxiv=1201.2052 | doi=10.1051/0004-6361/201117691 | s2cid=55586789 }}

| radius = {{Val|1.92|0.12|0.03}}

| luminosity = {{Val|10.091|0.063}}

| temperature = {{Val|7432|231|67|fmt=commas}}

| gravity = {{Val|4.26|0.14}}

| metal_fe =

| rotational_velocity = 124

| age_myr = 950{{citation | last1=David | first1=Trevor J. | last2=Hillenbrand | first2=Lynne A. | title=The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets | journal=The Astrophysical Journal | volume=804 | issue=2 | pages=146 | year=2015 | bibcode=2015ApJ...804..146D | doi=10.1088/0004-637X/804/2/146 | arxiv=1501.03154 | s2cid=33401607 | postscript=. }}

}}

{{Starbox catalog

| names={{odlist | F=18 Aur | SAO=57893 | GC=6504 | HIP=24832 | HR=1734 | ADS=3893 | BD=+33°1010 | HD=34499 | WDS=J05194+3359 }}{{cite simbad | title=18 Aur | accessdate=2019-05-21 }}

}}

{{Starbox reference

| Simbad=18+Aur

}}

{{Starbox end}}

18 Aurigae is a star located 233 light years away from the Sun in the northern constellation of Auriga. The brightness of this object is near the limit of visibility to the naked eye under good viewing conditions, appearing as a dim, white-hued star with an apparent visual magnitude of 6.49. The star is moving away from the Sun with a heliocentric radial velocity of 7 km/s.

This is an ordinary A-type main-sequence star with a stellar classification of A7 V, which indicates it is generating energy by hydrogen fusion at its core. The object is 950 million years old with a high rate of spin, showing a projected rotational velocity of 124 km/s. It has 1.7 times the mass of the Sun and 1.9 times the Sun's radius. The star is radiating 10 times the luminosity of the Sun from its photosphere at an effective temperature of 7,432 K.

18 Aurigae has a magnitude 12.50 companion star at an angular separation of {{Val|3.90|ul=arcsecond}} along a position angle of 167°, as of 2006.{{cite journal | display-authors=1 | last1=Mason | first1=B. D. | last2=Wycoff | first2=G. L. | last3=Hartkopf | first3=W. I. | last4=Douglass | first4=G. G. | last5=Worley | first5=C. E. | title=The Washington Visual Double Star Catalog | journal=The Astronomical Journal | volume=122 | issue=6 | pages=3466 | year=2014 | bibcode=2001AJ....122.3466M | doi=10.1086/323920 | doi-access=free }}