S Muscae

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

{{Starbox begin

| name= S Muscae

}}

{{Starbox image

| image=

{{Location mark

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

|label=|position=right

|mark=Red circle.svg|mark_width=8|mark_link=S Mus|x=576|y=406

}}

|caption=Location of S Muscae (circled)

}}

{{Starbox observe

| epoch=J2000

| ra={{RA|12|12|47.01834}}{{cite journal|bibcode=2007A&A...474..653V|title=Validation of the new Hipparcos reduction|journal=Astronomy and Astrophysics|volume=474|issue=2|pages=653–664|last1=Van Leeuwen|first1=F.|year=2007|doi=10.1051/0004-6361:20078357|arxiv = 0708.1752 |s2cid=18759600}}

| dec={{DEC|−70|09|06.4363}}

| appmag_v=6.394 {{nowrap|(5.89 - 6.49)}}

|constell= Musca

}}

{{Starbox character

| class={{nowrap|F6Ib (F6-G0) + B5V{{cite journal|bibcode=2014yCat....1.2023S|title=VizieR Online Data Catalog: Catalogue of Stellar Spectral Classifications (Skiff, 2009-2014)|journal=VizieR On-line Data Catalog: B/Mk. Originally Published in: Lowell Observatory (October 2014)|volume=1|last1=Skiff|first1=B. A.|year=2014}}}}

| b-v=+1.00{{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}}

| u-b=+0.66

| variable=δ Cepheid

}}

{{Starbox astrometry

| radial_v=−1.91{{cite journal|bibcode=2004A&A...424..727P|title=SB9: The ninth catalogue of spectroscopic binary orbits|journal=Astronomy and Astrophysics|volume=424|issue=2|pages=727–732|last1=Pourbaix|first1=D.|last2=Tokovinin|first2=A. A.|last3=Batten|first3=A. H.|last4=Fekel|first4=F. C.|last5=Hartkopf|first5=W. I.|last6=Levato|first6=H.|last7=Morrell|first7=N. I.|last8=Torres|first8=G.|last9=Udry|first9=S.|year=2004|doi=10.1051/0004-6361:20041213|arxiv = astro-ph/0406573 |s2cid=119387088}}

| prop_mo_ra=−7.79

| prop_mo_dec=−0.60

| parallax=1.99

| p_error=0.84

| parallax_footnote=

| dist_pc=863

| absmag_v=−4.01{{cite journal|bibcode=2013AJ....146...93E|arxiv=1307.7123|title=Binary Cepheids: Separations and Mass Ratios in 5 M ⊙ Binaries|journal=The Astronomical Journal|volume=146|issue=4|pages=93|last1=Remage Evans|first1=Nancy|last2=Bond|first2=Howard E.|last3=Schaefer|first3=Gail H.|last4=Mason|first4=Brian D.|last5=Karovska|first5=Margarita|last6=Tingle|first6=Evan|year=2013|doi=10.1088/0004-6256/146/4/93|s2cid=34133110}}

}}

{{Starbox orbit

| reference = {{cite journal|bibcode=2004MNRAS.350...95P|title=The orbits of southern binary Cepheids|journal=Monthly Notices of the Royal Astronomical Society|volume=350|pages=95–112|last1=Petterson|first1=O. K. L.|last2=Cottrell|first2=P. L.|last3=Albrow|first3=M. D.|year=2004|issue=1|doi=10.1111/j.1365-2966.2004.07555.x|doi-access=free}}

| primary =

| name =

| period =

| period_unitless = 504.9 ± 0.07

| axis =

| axis_unitless = 794 AU

| eccentricity = 0.08 ± 0.002

| inclination = 32 ± 1

| node =

| periastron =

| periarg =

| periarg_primary =

| k1 = 14.7 ± 0.2

| k2 =

}}

{{Starbox detail

| mass=6.2

| radius=65.1{{cite journal|bibcode=2005AcA....55..247M|arxiv=astro-ph/0507076|title=Mean Angular Diameters and Angular Diameter Amplitudes of Bright Cepheids|journal=Acta Astronomica|volume=55|pages=247|last1=Moskalik|first1=P.|last2=Gorynya|first2=N. A.|year=2005}}

| luminosity=3,467

| temperature=

| metal=+0.18{{cite journal|bibcode= 2009A&A...504..959K|title= Observational studies of Cepheid amplitudes. I. Period-amplitude relationships for Galactic Cepheids and interrelation of amplitudes|journal= Astronomy and Astrophysics|volume= 504|issue= 3|pages= 959|last1= Klagyivik|first1= P.|last2= Szabados|first2= L.|year= 2009|doi= 10.1051/0004-6361/200811464|arxiv = 0908.3561 |s2cid= 18283579}}

| rotation=

| component2=companion

| mass2=5.3

| temperature2=17,000{{cite journal|bibcode=2006ApJ...647.1387E|arxiv=astro-ph/0607489|title=Cepheid Masses: FUSE Observations of S Muscae|journal=The Astrophysical Journal|volume=647|issue=2|pages=1387–1392|last1=Evans|first1=Nancy Remage|last2=Massa|first2=Derck|last3=Fullerton|first3=Alexander|last4=Sonneborn|first4=George|last5=Iping|first5=Rosina|year=2006|doi=10.1086/505519|s2cid=119020617}}

| age_myr2=

}}

{{Starbox catalog

| names= S Mus, HR 4645, SAO 251791, CD−69°977, GSC 09231-00752, HD 106111, GC 16679, HIP 59551, AAVSO 1207-69

}}

{{Starbox reference

|Simbad=S+Muscae

}}

{{Starbox end}}

S Muscae is a classical (δ) Cepheid variable star in the constellation Musca about 2,600 light years away.

File:SMusLightCurve.png for S Muscae, plotted from TESS data]]

S Muscae is a yellow supergiant ranging between spectral types F6Ib and G0Ib and magnitudes 5.89 to 6.49 over a period of 9.66 days.{{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}} It is a luminous star around six times as massive as the Sun and 65.1 times the radius of the Sun. It is a binary star with a blue-white main sequence star companion likely to be of spectral type B3V to B5V with a mass of just over five solar masses,{{cite journal|display-authors=4|bibcode = 1997ApJ...477..916B|doi=10.1086/303725|title = The Mass of the Classical Cepheid S Muscae|journal = The Astrophysical Journal|volume = 477|issue = 2|pages = 916|year = 1997|last1 = Bohm-Vitense|first1 = Erika|last2 = Remage Evans|first2 = Nancy|last3 = Carpenter|first3 = Kenneth|last4 = Beck-Winchatz|first4 = Bernhard|last5 = Robinson|first5 = Richard|doi-access = free}} one of the hottest and brightest companions of a Cepheid known. The two stars orbit each other every 505 days.{{cite journal|bibcode=1990PASP..102..551E|doi=10.1086/132668|title=The orbit and colors of the Cepheid S MUSCAE|journal=Publications of the Astronomical Society of the Pacific|volume=102|pages=551|year=1990|last1=Evans|first1=Nancy Remage|doi-access=free}}

S Muscae has been found to lie within the faint star cluster ASCC 69.{{cite journal|bibcode=2014ApJ...785L..25E|arxiv=1403.6939|title=X-Ray Detection of the Cluster Containing the Cepheid S Mus|journal=The Astrophysical Journal Letters|volume=785|issue=2|pages=L25|last1=Remage Evans|first1=Nancy|last2=Pillitteri|first2=Ignazio|last3=Wolk|first3=Scott|last4=Guinan|first4=Edward|last5=Engle|first5=Scott|last6=Bond|first6=Howard E.|last7=Schaefer|first7=Gail H.|last8=Karovska|first8=Margarita|last9=Depasquale|first9=Joseph|last10=Tingle|first10=Evan|year=2014|doi=10.1088/2041-8205/785/2/L25|s2cid=119113620}}