RT Aurigae

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

{{Starbox begin

|name=RT Aurigae

}}

{{Starbox image

| image=

{{Location mark

|image=Auriga constellation map.svg

|float=center

|alt=

|label=

|position=right

|width=280

|mark=Red circle.svg

|mark_width=10

|mark_link=RT Aur

|x=184|y=688

}}

|caption=Location of RT Aur (circled)

}}

{{Starbox observe

|epoch=J2000

|ra={{RA|06|28|34.08818}}

|dec={{DEC|+30|29|34.9296}}

|appmag_v=5.75{{Cite journal | doi = 10.1051/0004-6361/201014247| title = The PASTEL catalogue of stellar parameters| year = 2010| last1 = Soubiran | first1 = C.| last2 = Le Campion | first2 = J. -F. | last3 = Cayrel De Strobel | first3 = G.| last4 = Caillo | first4 = A.| journal = Astronomy and Astrophysics| volume = 515| pages = A111| bibcode = 2010A&A...515A.111S|arxiv = 1004.1069 | s2cid = 118362423}} {{nowrap|(5.00 - 5.82)}}

|constell=Auriga

}}

{{Starbox character

|class=F8Ib{{cite journal|bibcode=2008MNRAS.389..869E|title=A catalogue of multiplicity among bright stellar systems|journal=Monthly Notices of the Royal Astronomical Society|volume=389|issue=2|pages=869|last1=Eggleton|first1=P. P.|last2=Tokovinin|first2=A. A.|year=2008|doi=10.1111/j.1365-2966.2008.13596.x|doi-access=free |arxiv = 0806.2878 |s2cid=14878976}} {{nowrap|(F4Ib - G4Ib{{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}})}}

|r-i =

|v-r =

|b-v = 0.74

|u-b = 0.5{{cite journal|bibcode=2002yCat.2237....0D|title=VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system|journal=CDS/ADC Collection of Electronic Catalogues|volume=2237|pages=0|last1=Ducati|first1=J. R.|year=2002}}

|variable=δ Cep

}}

{{Starbox astrometry

|radial_v=20.30{{cite journal|bibcode= 2006AstL...32..759G |title= Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system |journal= Astronomy Letters |volume= 32 |issue= 11 |pages= 759–771 |last1= Gontcharov |first1= G. A. |year= 2006 |doi= 10.1134/S1063773706110065 |arxiv = 1606.08053 |s2cid= 119231169 }}

|prop_mo_ra=−0.492

|prop_mo_dec=−13.441

|pm_footnote =

|parallax=1.8153

|p_error=0.1222

| parallax_footnote={{cite Gaia EDR3|3435571660360952704}}

|dist_ly=1,540

|dist_pc=473

|absmag_v=−3.09{{Cite journal | doi = 10.1051/0004-6361/201220446| title = Baade-Wesselink distances to Galactic and Magellanic Cloud Cepheids and the effect of metallicity| journal = Astronomy & Astrophysics| volume = 550| pages = A70| year = 2013| last1 = Groenewegen | first1 = M. A. T.| bibcode = 2013A&A...550A..70G|arxiv = 1212.5478 | s2cid = 118665355}}

}}

{{Starbox detail

|mass=4.4{{cite journal |last1=Anders |first1=F. |last2=Khalatyan |first2=A. |last3=Chiappini |first3=C. |last4=Queiroz |first4=A. B. |last5=Santiago |first5=B. X. |last6=Jordi |first6=C. |last7=Girardi |first7=L. |last8=Brown |first8=A. G. A. |last9=Matijevič |first9=G. |last10=Monari |first10=G. |last11=Cantat-Gaudin |first11=T. |last12=Weiler |first12=M. |last13=Khan |first13=S. |last14=Miglio |first14=A. |last15=Carrillo |first15=I. |last16=Romero-Gómez |first16=M. |last17=Minchev |first17=I. |last18=de Jong |first18=R. S. |last19=Antoja |first19=T. |last20=Ramos |first20=P. |last21=Steinmetz |first21=M. |last22=Enke |first22=H. |title=Photo-astrometric distances, extinctions, and astrophysical parameters for Gaia DR2 stars brighter than G = 18 |journal=Astronomy & Astrophysics |date=August 2019 |volume=628 |pages=A94 |doi=10.1051/0004-6361/201935765 |issn=0004-6361 |bibcode=2019A&A...628A..94A |arxiv=1904.11302 |doi-access=free}}

|radius= {{Val|35|1}}

|luminosity= {{Val|1451|124|fmt=commas}}

|temperature= {{Val|6034|66|fmt=commas}}

|metal=0.1

|gravity=1.42

|rotational_velocity=8.8{{cite journal |last1=De Medeiros |first1=J. R. |last2=Alves |first2=S. |last3=Udry |first3=S. |last4=Andersen |first4=J. |last5=Nordström |first5=B. |last6=Mayor |first6=M. |title=A catalog of rotational and radial velocities for evolved stars: V. Southern stars⋆⋆⋆ |journal=Astronomy & Astrophysics |date=January 2014 |volume=561 |pages=A126 |doi=10.1051/0004-6361/201220762 |issn=0004-6361 |bibcode=2014A&A...561A.126D |arxiv=1312.3474|doi-access=free}}

|age_myr=85{{cite journal |doi=10.1111/j.1365-2966.2011.20161.x |title=Galactic restrictions on iron production by various types of supernovae |year=2012 |last1=Acharova |first1=I. A. |last2=Mishurov |first2=Yu. N. |last3=Kovtyukh |first3=V. V. |journal=Monthly Notices of the Royal Astronomical Society |volume=420 |issue=2 |pages=1590–1605 |doi-access=free |s2cid=118404944 |arxiv=1111.2152 |bibcode=2012MNRAS.420.1590A }}

}}

{{Starbox catalog

|names=48 Aurigae, HD 45412, BD+30°1238, HIP 30827, SAO 59128, HR 2332

}}

{{Starbox reference

|Simbad=HD+45412

|ARICNS=

}}{{starbox sources|HIP|CCDM|HR}}

{{Starbox end}}

RT Aurigae (RT Aur, 48 Aurigae) is a yellow supergiant variable star in the constellation Auriga, about 1,500 light years from Earth. Although its brightness is variable, it as consistently visible to the naked eye under good observing conditions.

File:RTAurLightCurve.png light curve for RT Aurigae, adapted from Kiss (1998)]]

RT Aurigae is an F to G type Classical Cepheid variable which varies from magnitude +5.00 to +5.82 with a period of 3.728309 days. The variability was discovered in 1905, by an English schoolmaster and amateur astronomer, Thomas Hinsley Astbury. It was quickly recognised as a member of the class of Cepheid variables, but their nature was not understood at that time. Radial velocity changes were detected corresponding to the brightness variations, but the idea that these were caused by stellar pulsations and temperature changes was largely dismissed in favour of orbital motions of a binary star.{{cite journal|bibcode=1909PASP...21..119D|title=The Orbits of the Cepheid Variables Y Sagittarii and RT Auriga; with a Discussion of the Possible Causes of this Type of Stellar Variation|journal=Publications of the Astronomical Society of the Pacific|volume=21|issue=126|pages=119–136|last1=Duncan|first1=J. C.|year=1909|doi=10.1086/121905|doi-access=free}} More accurate observations eventually proved beyond doubt that the brightness variations were caused by pulsations in the atmospheres of the stars, with the stars being smallest and hottest near maximum brightness.{{cite journal|bibcode=1916ApJ....44..273S|title=The variations in spectral type of twenty Cepheid variables|journal=Astrophysical Journal|volume=44|pages=273|last1=Shapley|first1=H.|year=1916|doi=10.1086/142295|doi-access=free}}

RT Aurigae has been suspected to be a spectroscopic binary system, but this has not been confirmed.{{cite journal|bibcode=1992ApJ...384..220E|title=A magnitude-limited survey of Cepheid companions in the ultraviolet|journal=Astrophysical Journal|volume=384|pages=220|last1=Evans|first1=Nancy R.|year=1992|doi=10.1086/170865|doi-access=free}}{{Cite journal | doi = 10.1086/523656| title = The Period Changes of the Cepheid RT Aurigae| journal = Publications of the Astronomical Society of the Pacific| volume = 119| issue = 861| pages = 1247| year = 2007| last1 = Turner | first1 = D. G. | last2 = Bryukhanov | first2 = I. S. | last3 = Balyuk | first3 = I. I. | last4 = Gain | first4 = A. M. | last5 = Grabovsky | first5 = R. A. | last6 = Grigorenko | first6 = V. D. | last7 = Klochko | first7 = I. V. | last8 = Kosa-Kiss | first8 = A. | last9 = Kosinsky | first9 = A. S. | last10 = Kushmar | first10 = I. J. | last11 = Mamedov | first11 = V. T. | last12 = Narkevich | first12 = N. A. | last13 = Pogosyants | first13 = A. J. | last14 = Semenyuta | first14 = A. S. | last15 = Sergey | first15 = I. M. | last16 = Schukin | first16 = V. V. | last17 = Strigelsky | first17 = J. B. | last18 = Tamello | first18 = V. G. | last19 = Lane | first19 = D. J. | last20 = Majaess | first20 = D. J. | bibcode = 2007PASP..119.1247T|arxiv = 0709.3085 | s2cid = 18243829}} The strongest evidence was found in 2013 using CHARA array optical interferometry. The companion would be 6.7 magnitudes fainter than the supergiant primary, cooler and fainter than an F0 main sequence star. The two stars are separated by 2.1 milli-arc seconds.{{cite journal|bibcode=2015A&A...579A..68G|arxiv=1505.02715|title=Robust high-contrast companion detection from interferometric observations. The CANDID algorithm and an application to six binary Cepheids|journal=Astronomy & Astrophysics|volume=579|pages=A68|last1=Gallenne|first1=A.|last2=Mérand|first2=A.|last3=Kervella|first3=P.|last4=Monnier|first4=J. D.|last5=Schaefer|first5=G. H.|last6=Baron|first6=F.|last7=Breitfelder|first7=J.|last8=Le Bouquin|first8=J. B.|last9=Roettenbacher|first9=R. M.|last10=Gieren|first10=W.|last11=Pietrzyński|first11=G.|last12=McAlister|first12=H.|last13=Ten Brummelaar|first13=T.|last14=Sturmann|first14=J.|last15=Sturmann|first15=L.|last16=Turner|first16=N.|last17=Ridgway|first17=S.|last18=Kraus|first18=S.|year=2015|doi=10.1051/0004-6361/201525917|s2cid=1118066}}