View source for Astronomy:XY Ursae Majoris

{{short description|Eclipsing binary star system in the constellation of Ursa Major}}
{{Starbox begin}}
{{Starbox image
| image = [[Image:XYUMaLightCurve.png|250px]]
| caption = A [[Astronomy:Light curve|light curve]] for XY Ursae Majoris, plotted from ''[[Astronomy:Transiting Exoplanet Survey Satellite|TESS]]'' data<ref name=MAST/>
}}
{{Starbox observe
 | epoch       = J2000.0
 | constell    = [[Astronomy:Ursa Major|Ursa Major]]
 | ra          = {{RA|09|09|55.935}}<ref name=GaiaEDR3/>
 | dec         = {{DEC|+54|29|17.72}}<ref name=GaiaEDR3/>
 | appmag_v    = 9.50<ref name=Anderson_Francis_2012/>
}}
{{Starbox character
 | type        = Main sequence
 | class       = {{nowrap|G2V + K5V}}<ref name=Lister_et_al_2001/>
 | b-v         = 0.765{{±|0.039}}<ref name=Anderson_Francis_2012/>
 | u-b         = 
 | variable    = Detached eclipsing binary, [[Astronomy:RS Canum Venaticorum variable|RS CVn]]<ref name=Samus_et_al_2017/>
}}
{{Starbox astrometry
 | radial_v    = −9.98{{±|0.83}}<ref name=Karataș_et_al_2004/>
 | prop_mo_ra  = −49.781
 | prop_mo_dec = −182.641
 | pm_footnote = <ref name=GaiaEDR3/>
 | parallax    = 14.7223
 | p_error     = 0.0137
 | parallax_footnote = <ref name=GaiaEDR3/>
 | absmag_v    = 5.41<ref name=Anderson_Francis_2012/>
}}
{{Starbox orbit
 | reference   = <ref name=Pribulla_et_al_2007/>
 | primary     = <!--Primary name -->
 | name        = <!--Companion name-->
 | period_unitless = 0.4789961&nbsp;d
 | axis        = <!--(a) Semimajor axis (in arcseconds)-->
 | axis_unitless = {{val|3.05|0.01|ul=Solar radius}}<ref name=Yuan2010/>
 | eccentricity = 0.0
 | inclination = 79.81<ref name=Yuan2010/>
 | node        = <!--(Ω) Longitude of node (in degrees)-->
 | periastron  = 2,453,821.6344{{±|0.0002}}
 | periarg     = <!--(ω) Argument of periastron (in degrees), secondary -->
 | periarg_primary = <!--(ω) Argument of periastron (in degrees), primary -->
 | k1          = 124.74{{±|0.28}}
 | k2          = 
}}
{{Starbox detail
 | component1  = Primary
 | mass        = 1.01{{±|0.01}}<ref name=Yuan2010/>
 | radius      = 1.22{{±|0.01}}<ref name=Yuan2010/>
 | luminosity  = 1.10{{±|0.02}}<ref name=Yuan2010/>
 | gravity     = 
 | temperature = 5,780<ref name=Lister_et_al_2001/>
 | metal_fe    = 
 | rotation    = 
 | rotational_velocity = 
 | age_myr     = 
 | component2  = Secondary
 | mass2       = 0.65{{±|0.01}}<ref name=Yuan2010/>
 | radius2     = 0.58{{±|0.01}}<ref name=Yuan2010/>
 | luminosity2 = 0.09{{±|0.01}}<ref name=Yuan2010/>
 | temperature2= 3,850<ref name=Lister_et_al_2001/>
}}
{{Starbox catalog
 | names = {{odlist | V=XY UMa | AG=+54 702 | BD=+55 1317 | HD=237786 | HIP=44998 | PPM=32024 | SAO=27143 }}<ref name=SIMBAD/>
}}
{{Starbox reference
 | Simbad = XY+UMa
}}
{{Starbox end}}

'''XY Ursae Majoris''' is a short period [[Astronomy:Binary star|binary star]] system in the northern [[Astronomy:Circumpolar constellation|circumpolar constellation]] of [[Astronomy:Ursa Major|Ursa Major]]. It is an [[Astronomy:Eclipsing binary|eclipsing binary]] with a baseline [[Astronomy:Apparent visual magnitude|apparent visual magnitude]] of 9.50.<ref name=Anderson_Francis_2012/> The system is located at a distance of 221.5&nbsp;[[Light year|light year]]s from the [[Astronomy:Sun|Sun]] based on [[Astronomy:Stellar parallax|parallax]] measurements,<ref name=GaiaEDR3/> but is drifting closer with a [[Astronomy:Radial velocity|radial velocity]] of −10&nbsp;km/s.<ref name=Karataș_et_al_2004/> It has a relatively high [[Astronomy:Proper motion|proper motion]], traversing the [[Celestial sphere|celestial sphere]] at the angular rate of {{val|0.191|u=arcsecond}}·yr<sup>−1</sup>.<ref name=Lepine_Shara_2005/>

The variability of this system was discovered by W. Strohmeier and its period was determined by R. Kippenhahn, with the findings announced in 1955.<ref name=Geyer1976/> It was found to be a detached [[Astronomy:Eclipsing binary|eclipsing binary]] system, and by 1963 a [[Astronomy:Variable star|variable]] primary component had been noted.<ref name=Lorenzi_Scaltriti_1977/> E. H. Geyer made intermittent [[Astronomy:Light curve|light curve]] studies of the system starting with its discovery up until 1975,<ref name=Geyer1976/> ascribing variability in the light curve to star spot activity on the primary component. The orbital period of the pair was determined to be {{val|0.479|u=days}},<ref name=Geyer1977/> with the [[Astronomy:Orbital plane|orbital plane]] inclined at an angle of 79.84° to the line of sight from the Earth.<ref name=Yuan2010/>

By 1990, enough data had been collected to identify a long term variation of the period, and it was hypothesized this was caused by a third body in the system orbiting the close binary.<ref name=Pojmanski_Geyer_1990/> The orbital period of this component was estimated to be ~30 years in 2001,<ref name=Chochol_et_al_2001/> then refined to 26.7&nbsp;years by 2010. If the [[Astronomy:Orbital plane|orbital plane]] of this component is the same as the inner pair, its mass would be 18% of the mass of the Sun. An alternative solution to the period change suggests magnetic activity causes shifts in the [[Physics:Angular momentum|angular momentum]] of the system, but this is considered less likely.<ref name=Yuan2010/>

This is a double-lined [[Astronomy:Spectroscopic binary|spectroscopic binary]] star system with an [[Astronomy:Orbital period|orbital period]] of {{cvt|0.4789961|days|hours|1|disp=out}}.<ref name=Pribulla_et_al_2007/> The primary component is a [[Astronomy:G-type main-sequence star|G-type main-sequence star]] with a [[Astronomy:Stellar classification|stellar classification]] of G2V.<ref name=Lister_et_al_2001/> It is an [[Astronomy:RS Canum Venaticorum variable|RS Canum Venaticorum-type variable]] that is [[Astronomy:Magnetic activity|magnetically active]]<ref name=Samus_et_al_2017/> and a bright [[Astronomy:Astrophysical X-ray source|X-ray source]].<ref name=Gong_et_al_2016/> Despite this, relatively few optical [[Astronomy:Flare star|flares]] have been observed.<ref name=Gong_et_al_2016/> The cooler secondary is a [[Astronomy:K-type main-sequence star|K-type main-sequence star]] of class K5V that is smaller and less massive than the primary.<ref name=Lister_et_al_2001/>

== References ==
{{reflist|refs=

<ref name=SIMBAD>{{cite simbad
 | title=XY UMa | access-date=2022-03-03 | postscript=. | mode=cs2 }}</ref>

<ref name=GaiaEDR3>{{Cite Gaia EDR3|1023682919309621632}}</ref>

<ref name=Anderson_Francis_2012>{{citation | postscript=.
 | last1=Anderson | first1=E. | last2=Francis | first2=Ch.
 | title=XHIP: An extended hipparcos compilation
 | journal=Astronomy Letters
 | volume=38 | issue=5 | pages=331 | year=2012
 | bibcode=2012AstL...38..331A | arxiv=1108.4971
 | doi=10.1134/S1063773712050015 | s2cid=119257644 }}</ref>

<ref name=Geyer1976>{{citation
 | title=Starspot Activities as an Interpretation for the Light Curve Changes of the Close Binary Star XY UMA
 | last=Geyer | first=E. H.
 | work=Structure and Evolution of Close Binary Systems; Proceedings of the Symposium, Cambridge, England, July 28-August 1, 1975
 | postscript=. Symposium sponsored by the International Astronomical Union.
 | display-editors=1 | editor1-first=P. | editor1-last=Eggleton
 | editor2-first=S. | editor2-last=Mitton
 | editor3-first=J.| editor3-last=Whelan
 | publication-place=Dordrecht
 | publisher=D. Reidel Publishing Co.
 | number=73 | date=1976 | volume=73 | page=313
 | bibcode=1976IAUS...73..313G }}</ref>

<ref name=Lorenzi_Scaltriti_1977>{{citation | postscript=.
 | title=The variable light-curve of the eclipsing binary XY UMa
 | last1=Lorenzi | first1=L. | last2=Scaltriti | first2=F.
 | journal=Acta Astronomica
 | volume=27 | pages=273–279
 | date=1977 | bibcode=1977AcA....27..273L }}</ref>

<ref name=MAST>{{cite web |title=MAST: Barbara A. Mikulski Archive for Space Telescopes |url=https://mast.stsci.edu/portal/Mashup/Clients/Mast/Portal.html |publisher=Space Telescope Science Institute |access-date=8 December 2021}}</ref>

<ref name=Geyer1977>{{citation | postscript=.
 | title=Remarks on Erratic Period Fluctuations of Detached Close Binaries and the Constancy of the Orbital Period of XY UMa
 | last=Geyer | first=E. H.
 | journal=Astrophysics and Space Science
 | volume=48 | issue=1 | pages=137–144 | date=May 1977
 | doi=10.1007/BF00643045 | bibcode=1977Ap&SS..48..137G | s2cid=120596800
 }}</ref>

<ref name=Samus_et_al_2017>{{citation | postscript=.
 | title=General catalogue of variable stars | version=GCVS 5.1
 | last1=Samus' | first1=N. N | last2=Kazarovets | first2=E. V
 | last3=Durlevich | first3=O. V | last4=Kireeva | first4=N. N
 | last5=Pastukhova | first5=E. N | journal=Astronomy Reports
 | display-authors=1 | volume=61 | issue=1 | pages=80 | year=2017
 | bibcode=2017ARep...61...80S | s2cid=125853869
 | doi=10.1134/S1063772917010085 }}</ref>

<ref name=Pojmanski_Geyer_1990>{{citation | postscript=.
 | title=The period behaviour of the spotted binary XY UMa
 | last1=Pojmanski | first1=G. | last2=Geyer | first2=E. H.
 | journal=Acta Astronomica
 | volume=40 | page=245 | date=1990
 | bibcode=1990AcA....40..245P }}</ref>

<ref name=Chochol_et_al_2001>{{citation | postscript=.
 | title=An active binary XY UMa revisited
 | display-authors=1 | last1=Pribulla | first1=T.
 | last2=Chochol | first2=D. | last3=Heckert | first3=P. A.
 | last4=Errico | first4=L. | last5=Vittone | first5=A. A.
 | last6=Parimucha | first6=Š. | last7=Teodorani | first7=M.
 | journal=Astronomy and Astrophysics
 | volume=371 | pages=997–1011 | date=June 2001
 | issue=3
 | doi=10.1051/0004-6361:20010459 | bibcode=2001A&A...371..997P | doi-access=free }}</ref>

<ref name=Yuan2010>{{citation | postscript=.
 | title=Period Variation and Asymmetry Light Curves of XY Ursae Majoris
 | last=Yuan | first=Jinzhao
 | journal=The Astronomical Journal
 | volume=139 | issue=5 | pages=1801–1807 | date=May 2010
 | doi=10.1088/0004-6256/139/5/1801 | bibcode=2010AJ....139.1801Y | doi-access=free }}</ref>

<ref name=Lister_et_al_2001>{{citation | postscript=.
 | title=Starspot distributions on XY UMa during 1997-2000 from eclipse mapping
 | display-authors=1 | last1=Lister | first1=T. A.
 | last2=Collier Cameron | first2=A. | last3=Hilditch | first3=R. W.
 | journal=Monthly Notices of the Royal Astronomical Society
 | volume=326 | issue=4 | pages=1489–1498 | date=October 2001
 | doi=10.1111/j.1365-2966.2001.04712.x | bibcode=2001MNRAS.326.1489L | doi-access=free }}</ref>

<ref name=Gong_et_al_2016>{{citation | postscript=.
 | title=Three X-ray flares near primary eclipse of the RS CVn binary XY UMa
 | last1=Gong | first1=Hang | last2=Osten | first2=Rachel
 | last3=Maccarone | first3=Thomas | last4=Reale | first4=Fabio
 | last5=Liu | first5=Ji-Feng | last6=Heckert | first6=Paul A.
 | display-authors=1 | journal=Research in Astronomy and Astrophysics
 | volume=16 | issue=8 | id=131
 | date=August 2016 | page=014
 | doi=10.1088/1674-4527/16/8/131
 | arxiv=1605.09262 | bibcode=2016RAA....16..131G | s2cid=118443682
 }}</ref>

<ref name=Lepine_Shara_2005>{{citation | postscript=.
 | last1=Lépine | first1=Sébastien | last2=Shara | first2=Michael M.
 | title=A Catalog of Northern Stars with Annual Proper Motions Larger than 0.15" (LSPM-NORTH Catalog)
 | journal=The Astronomical Journal
 | volume=129 | issue=3 | pages=1483–1522 | date=March 2005
 | doi=10.1086/427854 | bibcode=2005AJ....129.1483L
 | arxiv=astro-ph/0412070 | s2cid=2603568 }}</ref>

<ref name=Pribulla_et_al_2007>{{citation | postscript=.
 | title=Radial Velocity Studies of Close Binary Stars. XII
 | display-authors=1 | last1=Pribulla | first1=Theodor
 | last2=Rucinski | first2=Slavek M. | last3=Conidis | first3=George
 | last4=DeBond | first4=Heide | last5=Thomson | first5=J. R.
 | last6=Gazeas | first6=Kosmas | last7=Ogłoza | first7=Waldemar
 | journal=The Astronomical Journal
 | volume=133 | issue=5 | pages=1977–1987
 | date=May 2007 | doi=10.1086/512772
 | arxiv=astro-ph/0611875 | bibcode=2007AJ....133.1977P }}</ref>

<ref name=Karataș_et_al_2004>{{citation | postscript=.
 | title=Kinematics of chromospherically active binaries and evidence of an orbital period decrease in binary evolution
 | last1=Karataș | first1=Yüksel | last2=Bilir | first2=Selçuk
 | last3=Eker | first3=Zeki | last4=Demircan | first4=Osman
 | last5=Liebert | first5=James | last6=Hawley | first6=Suzanne L.
 | last7=Fraser | first7=Oliver J. | last8=Covey | first8=Kevin R.
 | last9=Lowrance | first9=Patrick | last10=Kirkpatrick | first10=J. Davy
 | last11=Burgasser | first11=Adam J. | display-authors=1
 | journal=Monthly Notices of the Royal Astronomical Society
 | volume=349 | issue=3 | pages=1069–1092 | year=2004
 | bibcode=2004MNRAS.349.1069K | arxiv=astro-ph/0404219
 | doi=10.1111/j.1365-2966.2004.07588.x | s2cid=15290475 }}</ref>

}}

==Further reading==
{{Div col|small=yes}}
*{{citation | postscript=.
 | title=Period Changes in Four Short-Period Spotted Binaries: UV Piscium, YY Geminorum, CG Cygni, and XY Ursae Majoris
 | last1=Sowell | first1=James R. | last2=Hughes | first2=Scott B.
 | last3=Hall | first3=Douglas S. | last4=Howard | first4=Bruce A.
 | display-authors=1 | journal=The Astronomical Journal
 | volume=122 | issue=4 | pages=1965–1973 | date=October 2001
 | doi=10.1086/323091 | bibcode=2001AJ....122.1965S | s2cid=121917917
 | doi-access=free }}
*{{citation | postscript=.
 | title=Times of Minimum Light for XY Ursae Majoris
 | last1=Yeates | first1=C. M. | last2=Hintz | first2=E. G.
 | last3=Joner | first3=M. D. | last4=Schwendiman | first4=L. R.
 | display-authors=1 | journal=Information Bulletin on Variable Stars
 | volume=4943 | number=1 | date=August 2000
 | page=1
 | bibcode=2000IBVS.4943....1Y }}
*{{citation | postscript=.
 | title=Multicolour high-speed photometry and Hα spectroscopy of XY UMa
 | display-authors=1 | last1=Kjurkchieva | first1=D.
 | last2=Marchev | first2=D. | last3=Ogloza | first3=W.
 | journal=Astronomy and Astrophysics
 | volume=354 | pages=909–914 | date=February 2000
 | bibcode=2000A&A...354..909K }}
*{{citation | postscript=.
 | title=Time-resolved Spectroscopy of RS Canum Venaticorum Short-Period Systems. II. RT Andromedae, WY Cancri, and XY Ursae Majoris
 | last1=Arévalo | first1=M. J. | last2=Lázaro | first2=C.
 | journal=The Astronomical Journal
 | volume=118 | issue=2 | pages=1015–1033 | date=August 1999
 | doi=10.1086/300952 | bibcode=1999AJ....118.1015A | s2cid=121443644
 | doi-access=free }}
*{{citation | postscript=.
 | title=The RS CVn binary XY UMa as a member of a triple system
 | display-authors=1 | last1=Chochol | first1=D.
 | last2=Pribulla | first2=T. | last3=Teodorani | first3=M.
 | last4=Errico | first4=L. | last5=Vittone | first5=A. A.
 | last6=Milano | first6=L. | last7=Barone | first7=F.
 | journal=Astronomy and Astrophysics
 | volume=340 | pages=415–418 | date=December 1998
 | bibcode=1998A&A...340..415C }}
*{{citation | postscript=.
 | title=Orbital Solutions for Three RS CVn Systems: WY Cnc, SV Cam and XY UMa
 | last=Pojmanski | first=G.
 | journal=Acta Astronomica
 | volume=48 | pages=711–727 | date=December 1998
 | bibcode=1998AcA....48..711P }}
*{{citation | postscript=.
 | title=A ROSAT observation of the eclipsing binary system XY UMa
 | last=Jeffries | first=R. D.
 | journal=Monthly Notices of the Royal Astronomical Society
 | volume=295 | issue=4 | pages=825–833 | date=April 1998
 | doi=10.1046/j.1365-8711.1998.01272.x | bibcode=1998MNRAS.295..825J | doi-access=free }}
*{{citation | postscript=.
 | title=The orbital period study and photometric analysis of XY Ursae Majoris
 | last1=Erdem | first1=A. | last2=Gudur | first2=N.
 | journal=Astronomy and Astrophysics Supplement
 | volume=127 | pages=257–267 | date=January 1998
 | issue=2
 | doi=10.1051/aas:1998348 | bibcode=1998A&AS..127..257E | doi-access=free }}
*{{citation | postscript=.
 | title=An Orbital Solution for RS CVn Binary Star XY UMa
 | last1=Pojmanski | first1=G. | last2=Udalski | first2=A.
 | journal=Acta Astronomica
 | volume=47 | pages=451–466
 | date=October 1997 | bibcode=1997AcA....47..451P }}
*{{citation | postscript=.
 | title=Eclipse mapping of starspots on XY UMa in 1992 and 1995
 | last1=Collier Cameron | first1=A. | last2=Hilditch | first2=R. W.
 | journal=Monthly Notices of the Royal Astronomical Society
 | volume=287 | issue=3 | pages=567–574 | date=May 1997
 | doi=10.1093/mnras/287.3.567 | bibcode=1997MNRAS.287..567C | doi-access=free }}
*{{citation | postscript=.
 | title=V-Band Photometry of XY UMa in 1993 and 1995
 | last1=Jeffries | first1=R. D. | last2=Collins | first2=C.
 | last3=Elliott | first3=K. H. | last4=Helsdon | first4=S. F.
 | last5=Pittard | first5=J. M. | last6=Taylor | first6=S. B.
 | journal=Information Bulletin on Variable Stars
 | volume=4277 | number=1 | display-authors=1
 | date=December 1995 | page=1
 | bibcode=1995IBVS.4277....1J }}
*{{citation | postscript=.
 | title=High Precision Photometry of the RS-Canum Binary System XY-Ursae and a Dark-Zone Photometric Model
 | last1=Hilditch | first1=R. W. | last2=Bell | first2=S. A.
 | journal=Monthly Notices of the Royal Astronomical Society
 | volume=267 | issue=4 | page=1081 | date=April 1994
 | doi=10.1093/mnras/267.4.1081 | bibcode=1994MNRAS.267.1081H | doi-access=free }}
*{{citation | postscript=.
 | title=Spectroscopic observations of the RS CVn-type binary systems SV Cam and XY UMa
 | display-authors=1 | last1=Rainger | first1=P. P.
 | last2=Hilditch | first2=R. W. | last3=Edwin | first3=R. P.
 | journal=Monthly Notices of the Royal Astronomical Society
 | volume=248 | page=168 | date=January 1991
 | doi=10.1093/mnras/248.1.168 | bibcode=1991MNRAS.248..168R | doi-access=free }}
*{{citation | postscript=.
 | title=On the long term variability of the chromospheric active close binary XY Ursae Majoris
 | last=Geyer | first=E. H.
 | journal=Astronomische Gesellschaft Abstract Series
 | volume=6 | pages=79
 | date=1991 | bibcode=1991AGAb....6...79G }}
*{{citation | postscript=.
 | title=1990 BVR Photometry of XY UMa
 | last1=Zeilik | first1=M. | last2=de Blasi | first2=C. B.
 | last3=Gordon | first3=S. | last4=Ledlow | first4=M.
 | journal=Information Bulletin on Variable Stars
 | volume=3535 | number=1 | display-authors=1
 | date=October 1990 | page=1
 | bibcode=1990IBVS.3535....1Z }}
*{{citation | postscript=.
 | title=Infrared Photometry of XY-Ursae
 | last1=Arévalo | first1=M. J. | last2=Lázaro | first2=C.
 | journal=Astrophysics and Space Science
 | volume=169 | issue=1–2 | pages=247–249 | date=July 1990
 | doi=10.1007/BF00640725 | bibcode=1990Ap&SS.169..247A | s2cid=116674010
 }}
*{{citation | postscript=.
 | title=Coronal X-ray emission from the short-period eclipsing binary XY UMa
 | last1=Bedford | first1=D. K. | last2=Jeffries | first2=R. D.
 | last3=Geyer | first3=E. H. | last4=Vilhu | first4=O.
 | journal=Monthly Notices of the Royal Astronomical Society
 | volume=243 | pages=557–564 | date=April 1990
 | display-authors=1 | bibcode=1990MNRAS.243..557B }}
*{{citation | postscript=.
 | title=Infrared Photometry of the RS CVn Short-Period Systems XY UMa and WY CNC
 | last1=Arevalo | first1=M. J. | last2=Lazaro | first2=C.
 | journal=Astronomical Journal
 | volume=99 | page=983 | date=March 1990
 | doi=10.1086/115389 | bibcode=1990AJ.....99..983A }}
*{{citation | postscript=.
 | title=Light Curves for XY UMa
 | last1=Banks | first1=T. | last2=Budding | first2=E.
 | journal=Information Bulletin on Variable Stars
 | volume=3304 | number=1
 | date=March 1989 | page=1
 | bibcode=1989IBVS.3304....1B }}
*{{citation | postscript=.
 | title=1987 Photometry of XY Ursae Majoris
 | last1=Heckert | first1=P. | last2=Zeilik | first2=M.
 | journal=Information Bulletin on Variable Stars
 | volume=3253 | number=1 | display-authors=1
 | date=October 1988 | page=1
 | bibcode=1988IBVS.3253....1H }}
*{{citation | postscript=.
 | title=1988 BVRI Photometry of XY UMa
 | last1=Zeilik | first1=M. | last2=Cox | first2=D.
 | last3=de Blasi | first3=C. | last4=Ledlow | first4=M.
 | last5=Rhodes | first5=M. | last6=Williams | first6=T.
 | journal=Information Bulletin on Variable Stars
 | volume=3200 | number=1 | display-authors=1
 | date=June 1988 | page=1
 | bibcode=1988IBVS.3200....1Z }}
*{{citation | postscript=.
 | title=Photometric Observations and Interpretation of the Eclipsing Binary System Xy-Ursae
 | last=Jassur | first=D. M. Z.
 | journal=Astrophysics and Space Science
 | volume=128 | issue=2 | pages=369–375 | date=December 1986
 | doi=10.1007/BF00644585 | bibcode=1986Ap&SS.128..369J | s2cid=121784675
 }}
*{{citation | postscript=.
 | title=The X-Ray Light Curve of XY Ursae Maioris
 | display-authors=1 | last1=Bedford | first1=D. K.
 | last2=Vilhu | first2=O. | last3=Fuensalida | first3=J. J.
 | journal=Information Bulletin on Variable Stars
 | volume=2946 | number=1
 | date=October 1986 | page=1
 | bibcode=1986IBVS.2946....1B }}
*{{citation | postscript=.
 | title=Simultaneous Optical- and EXOSAT-Observations of the Spot Active Eclipsing Binary XY UMa
 | last1=Bedford | first1=D. K. | last2=Geyer | first2=E. H.
 | journal=Mitteilungen der Astronomischen Gesellschaft
 | volume=67 | page=305
 | date=1986 | bibcode=1986MitAG..67..305B }}
*{{citation | postscript=.
 | title=The short-period eclipsing system XY UMa : 1982 UBV light curves and a flare-like event
 | display-authors=1 | last1=Zeilik | first1=M.
 | last2=Elston | first2=R. | last3=Henson | first3=G.
 | journal=Astronomical Journal
 | volume=88 | pages=532–534 | date=April 1983
 | doi=10.1086/113339 | bibcode=1983AJ.....88..532Z }}
*{{citation | postscript=.
 | title=An Intense Optical Flare from XY UMa
 | last1=Zeilik | first1=M. | display-authors=1
 | last2=Elston | first2=R. | last3=Henson | first3=G.
 | journal=Information Bulletin on Variable Stars
 | volume=2200 | number=1 | date=September 1982
 | page=1
 | bibcode=1982IBVS.2200....1Z }}
*{{citation | postscript=.
 | title=1982 UBVR Photometric Observations of XY UMa
 | last1=Zeilik | first1=M. | last2=Batuski | first2=D.
 | last3=Elston | first3=R. | last4=Henson | first4=G.
 | last5=Schmolke | first5=P. | last6=Smith | first6=P.
 | journal=Information Bulletin on Variable Stars
 | volume=2169 | page=1 | display-authors=1
 | date=June 1982 | bibcode=1982IBVS.2169....1Z }}
*{{citation | postscript=.
 | title=A Polarimetric Investigation of the Eclipsing Binary XY Ursae Majoris
 | last1=Geyer | first1=E. H. | last2=Metz | first2=K.
 | journal=Astrophysics and Space Science
 | volume=52 | issue=2 | pages=351–356 | date=December 1977
 | doi=10.1007/BF01093871 | bibcode=1977Ap&SS..52..351G | s2cid=121665339
 }}
{{Div col end}}

{{Stars of Ursa Major}}

{{DEFAULTSORT:UX Ursae Majoris}}
<!-- Properties -->
[[Category:G-type main-sequence stars]]
[[Category:RS Canum Venaticorum variables]]
[[Category:K-type main-sequence stars]]
[[Category:Binary stars]]
[[Category:Eclipsing binaries]]
<!-- Location/Catalogues -->
[[Category:Durchmusterung objects]]
[[Category:Henry Draper Catalogue objects|237786]]
[[Category:Hipparcos objects|044998]]
[[Category:Objects with variable star designations|Ursae Majoris, UX]]

{{Sourceattribution|XY Ursae Majoris}}