View source for R Lyrae

{{Short description|Star in the constellation Lyra}}
{{distinguish|RR Lyrae}}
{{Starbox begin
| name=R Lyrae
}}
{{Starbox image
| image=[[File:Lyra constellation map.svg|260px]]
| caption=R Lyrae (labelled as 13)
}}
{{Starbox observe
| epoch=J2000.0
| constell=[[Lyra]]
| ra={{RA|18|55|20.101223}}<ref name=hipparcos>{{R:Van Leeuwen 2007 Validation of the new Hipparcos reduction}}</ref>
| dec={{DEC|+43|56|45.9215}}<ref name=hipparcos/>
| appmag_v=4.00<ref name=ducati>{{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|last1=Ducati|first1=J. R.|year=2002}}</ref> {{nowrap|(3.9 - 5.0<ref name=GCVS-R-Dor>{{cite web |title=GCVS Query=R Lyr |publisher=[[General Catalogue of Variable Stars]] @ [[Centre de données astronomiques de Strasbourg|Sternberg Astronomical Institute, Moscow, Russia]] |url=http://www.sai.msu.su/gcvs/cgi-bin/search.cgi?search=R+Lyr |accessdate=2012-08-22}}</ref>)}}
}}
{{Starbox character
| class=M5 III<ref name=aslan/>
| appmag_1_passband = [[J band (infrared)|J]]
| appmag_1 = &minus;0.90<ref name=ducati/>
| b-v=+1.59<ref name=ducati/>
| u-b=+1.41<ref name=ducati/>
| variable=[[Semiregular variable star|SRb]]<ref name=GCVS-R-Dor/>
}}
{{Starbox astrometry
| radial_v=&minus;27.15<ref>{{cite journal|bibcode=2009A&A...498..627F|title=Spectroscopic binaries among Hipparcos M giants,. I. Data, orbits, and intrinsic variations|journal=Astronomy and Astrophysics|volume=498|issue=2|pages=627|last1=Famaey|first1=B.|last2=Pourbaix|first2=D.|last3=Frankowski|first3=A.|last4=Van Eck|first4=S.|last5=Mayor|first5=M.|last6=Udry|first6=S.|last7=Jorissen|first7=A.|year=2009|doi=10.1051/0004-6361/200810698|arxiv = 0901.0934 |s2cid=18739721}}</ref>
| prop_mo_ra=21.05<ref name=hipparcos/>
| prop_mo_dec=82.06<ref name=hipparcos/>
| parallax=10.94
| p_error=0.12
| parallax_footnote=<ref name=hipparcos/>
| absmag_v=&minus;1.1<ref name=aslan>{{cite journal|bibcode=2004MNRAS.355..601Y|title=Period-luminosity relation for M-type semiregular variables from Hipparcos parallaxes|journal=Monthly Notices of the Royal Astronomical Society|volume=355|issue=2|pages=601|last1=Yeşilyaprak|first1=C.|last2=Aslan|first2=Z.|year=2004|doi=10.1111/j.1365-2966.2004.08344.x|doi-access=free}}</ref>
}}
{{Starbox detail
| mass = {{val|1.8|0.2}}<ref name=halabi/>
| radius = {{solar radius calculator|type=LT|4130|3313}}<ref name=halabi/>{{efn | name=radius | Applying the [[Stefan–Boltzmann law]] with a nominal [[sun|solar]] [[effective temperature]] of 5,772&nbsp;[[Kelvin|K]]:
:<math>\sqrt{\biggl(\frac{5,772}{3,313}\biggr)^4 \cdot 4,130} = 195\ R_\odot</math>.}}
| luminosity = 4,130<ref name=halabi/>{{efn|1=Calculated using the [[absolute bolometric magnitude]] of R lyrae, with respect to the Sun's absolute bolometric magnitude of 4.83:<br />10{{sup|0.4(4.74+(&minus;4.3)}} = 4130.48.}}
| temperature = 3,313<ref name=halabi>{{cite journal|bibcode=2015MNRAS.451.2957H|arxiv=1507.01517|title=Exploring masses and CNO surface abundances of red giant stars|journal=Monthly Notices of the Royal Astronomical Society|volume=451|issue=3|pages=2957|last1=Halabi|first1=Ghina M.|last2=Eid|first2=Mounib El|year=2015|doi=10.1093/mnras/stv1141|doi-access=free |s2cid=118707332}}</ref>
| metallicity_fe = &minus;0.29<ref name=pugniel/>
| gravity = 0.47<ref name=pugniel>{{cite journal|bibcode= 2011A&A...531A.165P|title= The atmospheric parameters and spectral interpolator for the MILES stars|journal= Astronomy & Astrophysics|volume= 531|pages= A165|last1= Prugniel|first1= Ph.|last2= Vauglin|first2= I.|last3= Koleva|first3= M.|year= 2011|doi= 10.1051/0004-6361/201116769|arxiv = 1104.4952 |s2cid= 54940439}}</ref>
| rotational_velocity =
| age =
}}
{{Starbox catalog
| names=[[Variable star designation|R]]&nbsp;Lyrae, [[Flamsteed designation|13]]&nbsp;Lyrae, [[Harvard Revised catalogue|HR]]&nbsp;7157, [[Bonner Durchmusterung|BD]]+43°3117, [[Henry Draper catalogue|HD]]&nbsp;175865, [[Smithsonian Astrophysical Observatory Star Catalog|SAO]]&nbsp;47919, [[Hipparcos catalogue|HIP]]&nbsp;92862, [[Boss General Catalogue|GC]]&nbsp;25996, [[Guide Star Catalog|GSC]]&nbsp;03131-02155
}}
{{Starbox reference
|Simbad=13+Lyrae
}}
{{Starbox end}}
'''R Lyrae''', also known as its [[Flamsteed designation]] '''13 Lyrae''', is a 4th [[apparent magnitude|magnitude]] [[semiregular variable star]] in the constellation [[Lyra]], approximately 350 [[light year]]s away from [[Earth]]. It is a [[red giant]] star of the [[spectral type]] M5III, currently at the last stages of [[Stellar evolution|evolution]]. It is much larger and brighter, yet cooler, than the [[Sun]]. In the near-[[infrared]] [[J band (infrared)|J band]], it is brighter than the nearby [[Vega]].
R Lyrae is unusual in that it is a red star with a high proper motion, greater than 50 milliarcseconds a year.<ref name=" Jiménez-Esteban">{{cite journal|author1=Jiménez-Esteban, F. M. |author2=Caballero, J. A. |author3=Dorda, R. |author4=Miles-Páez, P. A. |author5=Solano, E. |date=2012|title=Identification of red high proper-motion objects in Tycho-2 and 2MASS catalogues using Virtual Observatory tools|journal=Astronomy & Astrophysics|volume=539|pages=12|doi=10.1051/0004-6361/201118375 |bibcode=2012A&A...539A..86J|arxiv = 1201.5315 |s2cid=53404166 }}</ref> It is one of the brightest stars at the K band, having an [[apparent magnitude]] of &minus;2.08, only 14 stars are brighter.<ref>[https://simbad.cds.unistra.fr/simbad/sim-sam?Criteria=Kmag+%3C+-2.08&submit=submit+query&OutputMode=LIST&maxObject=10000&CriteriaFile= Kmag < -2.08]. [[SIMBAD]].</ref>
[[File:RLyrLightCurve.png|thumb|left|[[Photometric_system#Photometric_letters|Visual band]] [[light curve]]s for R&nbsp;Lyrae, adapted from Percy ''et al.'' (2001)<ref name="Percy"/>]]
The variability is not consistent and regular, but periods of 46, 64, 378, and 1,000 days have been reported, with the 46-day period being the strongest.<ref name=aslan/><ref name=glass>{{cite journal|bibcode=2007MNRAS.378.1543G|arxiv=0704.3150|title=Semiregular variables in the solar neighbourhood|journal=Monthly Notices of the Royal Astronomical Society|volume=378|issue=4|pages=1543–1549|last1=Glass|first1=I. S.|last2=Van Leeuwen|first2=F.|year=2007|doi=10.1111/j.1365-2966.2007.11903.x|doi-access=free |s2cid=14332208}}</ref>
It is calculated that R Lyrae was a {{solar mass|2.0}} star on the [[main sequence]], similar to [[Sirius|Sirius A]] today. It is now an oxygen-rich [[asymptotic giant branch]] star, with both hydrogen and helium shells fusing. Due to [[stellar mass loss]], R Lyrae now has a mass of {{solar mass|1.8}}.<ref name=halabi/>
==Notes==
{{Notelist}}
==References==
{{Reflist|refs=
<ref name="Percy">{{cite journal |last1=Percy |first1=John R. |last2=Wilson |first2=Joseph B. |last3=Henry |first3=Gregory W. |title=Long-Term VRI Photometry of Small-Amplitude Red Variables. I. Light Curves and Periods |journal=Publications of the Astronomical Society of the Pacific |date=August 2001 |volume=113 |issue=786 |pages=983–996 |doi=10.1086/322153 |bibcode=2001PASP..113..983P |s2cid=14609175 |doi-access=free }}</ref>
}}
{{Stars of Lyra}}
[[Category:Lyra]]
[[Category:Flamsteed objects|Lyrae, 13]]
[[Category:Objects with variable star designations|Lyrae, R]]
[[Category:Semiregular variable stars]]
[[Category:Bright Star Catalogue objects|7157]]
[[Category:Henry Draper Catalogue objects|175865]]
[[Category:Hipparcos objects|092862]]
[[Category:Durchmusterung objects]]
[[Category:M-type giants]]