View source for Astronomy:XX Persei

{{Short description|Star in the constellation Perseus}}
{{Starbox begin
| name = XX Persei
}}
{{Starbox image
| image=
{{Location mark
|image=Comet Lovejoy.jpg|alt=|float=center|width=360
|label=|position=right
|mark=Red circle.svg|mark_width=10|mark_link=XX Per
|x=431|y=395
}}
| caption=XX Persei (circled) near the [[Astronomy:Double Cluster|Double Cluster]] and Comet Lovejoy
| credit=Juan lacruz
}}
{{Starbox observe
| epoch=J2000
| ra={{RA|02|03|09.35854}}<ref name=dr3/>
| dec={{DEC|55|13|56.6229}}<ref name=dr3/>
| appmag_v=7.9 - 9.0<ref name=kiss/>
| constell=[[Astronomy:Perseus (constellation)|Perseus]]
}}
{{Starbox character
 | class=M4Ib + B7V<ref name=proust/>
 | b-v=
 | u-b=
 | variable=[[Astronomy:Semiregular variable star|SRc]]<ref name=gcvs/>
}}
{{Starbox astrometry
 | radial_v=
 | prop_mo_ra=−1.263<ref name=dr3/>
 | prop_mo_dec=−1.819<ref name=dr3/>
 | parallax=0.3980
 | p_error=0.0316
 | parallax_footnote=<ref name=dr3>{{cite Gaia DR3|456507783227720576}}</ref>
 | dist_pc=
 | dist_ly=
 | absmag_v=−4.6<ref name=stothers/>
}}
{{Starbox detail
 | mass=16<ref name=stothers/>
 | radius=548<ref name=messineo2019>{{cite journal |bibcode=2019AJ....158...20M |title=A Catalog of Known Galactic K-M Stars of Class I Candidate Red Supergiants in Gaia DR2 |last1=Messineo |first1=M. |last2=Brown |first2=A. G. A. |journal=The Astronomical Journal |year=2019 |volume=158 |issue=1 |pages=20 |doi=10.3847/1538-3881/ab1cbd |arxiv=1905.03744 |s2cid=148571616 |doi-access=free }}</ref> - 681<ref name="norris">{{Cite thesis|type=PhD|last=Norris|first=Ryan P.|date=2019|title=Seeing Stars Like Never Before: A Long-term Interferometric Imaging Survey of Red Supergiants|url=https://core.ac.uk/download/pdf/225164189.pdf|publisher=[[Organization:Georgia State University|Georgia State University]]}}</ref>
 | luminosity=42,000<ref name=messineo2019/>
 | temperature={{val|3,535|170|fmt=commas}}<ref name=messineo2019/>
 | metal=
 | rotation=
 | gravity=
 | age=
}}  
{{Starbox catalog
 | names= [[Astronomy:Variable star designation|XX]]&nbsp;Per, BD+54°444, [[Astronomy:Guide Star Catalog|GSC]]&nbsp;03689-01837, HD&nbsp;12401, [[Astronomy:Hipparcos|HIP]]&nbsp;9582, IRC+50052, [[Astronomy:2MASS|2MASS]]&nbsp;J02030935+5513566, HV&nbsp;3414, [[Astronomy:Smithsonian Astrophysical Observatory Star Catalog|SAO]]&nbsp;22875, AAVSO&nbsp;0156+54
}}
{{ Starbox reference
 | Simbad = XX+Persei
}}
{{Starbox end}}

'''XX Persei''' ('''IRC +50052''' / '''HIP 9582''' / '''BD+54°444''') is a semiregular variable [[Astronomy:Red supergiant|red supergiant]] star in the constellation [[Astronomy:Perseus (constellation)|Perseus]], between the [[Astronomy:Double Cluster|Double Cluster]] and the border with [[Astronomy:Andromeda (constellation)|Andromeda]].

==Variability==
[[File:XXPerLightCurve.png|thumb|left|A visual band light curve for XX&nbsp;Persei, plotted from ASAS-SN data<ref name="ASAS-SN"/>]]
XX Persei is a semiregular variable star of sub-type SRc, indicating a cool supergiant.  The [[Astronomy:General Catalogue of Variable Stars|General Catalogue of Variable Stars]] gives the period as 415 days.<ref name=gcvs/> It also shows a long secondary period which was originally given at 4,100 days.<ref name=stothers/> A more recent study shows only slow variations with a period of 3,150 ± 1,000 days.<ref name=kiss/>  Another study failed to find any long period up to 10,000 days.<ref name=percy/>

==Distance==
The most likely distance of XX Per is {{val|fmt=commas|2,290|ul=pc}}, from assumed membership of the [[Astronomy:Perseus OB1|Perseus OB1]] association.<ref name=spitzer/>  Gaia Data Release 3 includes a parallax of {{val|0.3980|0.0316|ul=mas}}, corresponding to a distance of around {{val|fmt=commas|2,500|u=pc}}.<ref name=dr3/>

==Characteristics==
XX Per is a red supergiant of spectral type M4Ib with an effective temperature below 4,000 [[Kelvin|K]]. It has a large infrared excess, indicating surrounding dust at a temperature of 900 K, but no masers have been detected.<ref name=fok/><ref name=verheyen/>

XX Persei has a mass of 16 [[Astronomy:Solar mass|solar mass]]es, above the limit beyond which stars end their lives as supernovae.<ref name=stothers/>

==Companions==
XX Persei is listed in multiple star catalogues with a companion of magnitude 9.8 {{val|223|ul="}} away.<ref name=wds>{{citation
 | 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 | year=2014 | volume=122 | issue=6 | page=3466 | bibcode=2001AJ....122.3466M
 | url=http://vizier.u-strasbg.fr/viz-bin/VizieR?-source=B/wds
 | accessdate=2016-09-04 | doi = 10.1086/323920 | doi-access=free }}</ref>  This star is BD+54°445 and it is an unrelated foreground object.  In addition, the spectrum of XX Persei shows absorption lines of a hot companion too close to be resolved.  The combined spectral type has been given as M4Ib + B7V,<ref name=proust/> while the UV spectrum of the companion has been used to derive a spectral classification of A.<ref name=buss/>

==See also==
* [[Astronomy:RS Persei|RS Persei]]
* [[Astronomy:S Persei|S Persei]]

==References==
{{reflist|refs=

<ref name="ASAS-SN">{{cite web |url=https://asas-sn.osu.edu/variables/lookup |website=ASAS-SN Variable Stars Database|title=ASAS-SN Variable Stars Database|publisher=ASAS-SN |access-date=6 January 2022}}</ref>

<ref name=buss>{{cite journal|bibcode=1988ApJ...335..331B|title=Hot components and circumstellar grains in M supergiant syncretic binaries|journal=Astrophysical Journal|volume=335|pages=331|last1=Buss|first1=Richard H.|last2=Snow|first2=Theodore P.|year=1988|doi=10.1086/166931|doi-access=free}}</ref>

<ref name=percy>{{cite journal|bibcode=2009JRASC.103...11P|title=Long Secondary Periods in Pulsating Red Supergiant Stars|journal=Journal of the Royal Astronomical Society of Canada|volume=103|pages=11|last1=Percy|first1=John R.|last2=Sato|first2=Hiromitsu|year=2009|issue=1}}</ref>

<ref name=verheyen>{{cite journal|bibcode=2012A&A...541A..36V|arxiv=1203.4727|title=SiO maser emission from red supergiants across the Galaxy . I. Targets in massive star clusters|journal=Astronomy & Astrophysics|volume=541|pages=A36|last1=Verheyen|first1=L.|last2=Messineo|first2=M.|last3=Menten|first3=K. M.|year=2012|doi=10.1051/0004-6361/201118265|s2cid=55630819}}</ref>

<ref name=gcvs>{{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=0|last1=Samus|first1=N. N.|last2=Durlevich|first2=O. V.|year=2009}}</ref>

<ref name=proust>{{cite journal|bibcode=1981A&AS...44..179P|title=A catalogue of variable-visual binary stars|journal=Astronomy and Astrophysics Supplement Series|volume=44|pages=179|last1=Proust|first1=D.|last2=Ochsenbein|first2=F.|last3=Pettersen|first3=B. R.|year=1981}}</ref>

<ref name=fok>{{cite journal|bibcode=2012ApJ...760...65F|arxiv=1209.6427|title=Maser Observations of Westerlund 1 and Comprehensive Considerations on Maser Properties of Red Supergiants Associated with Massive Clusters|journal=The Astrophysical Journal|volume=760|pages=65|last1=Fok|first1=Thomas K. T.|last2=Nakashima|first2=Jun-Ichi|last3=Yung|first3=Bosco H. K.|last4=Hsia|first4=Chih-Hao|last5=Deguchi|first5=Shuji|year=2012|issue=1|doi=10.1088/0004-637X/760/1/65|s2cid=53393926}}</ref>

<ref name=spitzer>{{cite journal|bibcode=2015MNRAS.447.3909R|arxiv=1501.02749|title=A Spitzer/IRAC characterization of Galactic AGB and RSG stars|journal=Monthly Notices of the Royal Astronomical Society|volume=447|issue=4|pages=3909|last1=Reiter|first1=Megan|last2=Marengo|first2=Massimo|last3=Hora|first3=Joseph L.|last4=Fazio|first4=Giovanni G.|year=2015|doi=10.1093/mnras/stu2725|s2cid=118515353}}</ref>

<ref name=stothers>{{cite journal|bibcode=1971A&A....10..290S|title=Luminosities, masses and periodicities of massive red supergiants|journal=Astronomy and Astrophysics|volume=10|pages=290|last1=Stothers|first1=R.|last2=Leung|first2=K. C.|year=1971}}</ref>

<ref name=kiss>{{cite journal|bibcode=2006MNRAS.372.1721K|arxiv=astro-ph/0608438|title=Variability in red supergiant stars: Pulsations, long secondary periods and convection noise|journal=Monthly Notices of the Royal Astronomical Society|volume=372|issue=4|pages=1721–1734|last1=Kiss|first1=L. L.|last2=Szabó|first2=Gy. M.|last3=Bedding|first3=T. R.|year=2006|doi=10.1111/j.1365-2966.2006.10973.x|s2cid=5203133}}</ref>

}}

{{Stars of Perseus}}

{{DEFAULTSORT:XX Persei}}
[[Category:Semiregular variable stars]]
[[Category:Perseus (constellation)]]
[[Category:Hipparcos objects|009582]]
[[Category:M-type supergiants]]
[[Category:Durchmusterung objects|BD+54 444]]
[[Category:2MASS objects|J02030935+5513566]]
[[Category:Objects with variable star designations|Persei, XX]]
[[Category:Henry Draper Catalogue objects|012401]]

{{Sourceattribution|XX Persei}}