{{Short description|Star in the constellation Centaurus}} {{Starbox begin | name=V803 Cen }} {{Starbox image | image = | caption = }} {{Starbox image | image = [[Image:V803CenLightCurve.png|250px]] | caption = Three [[light curve]]s for V803 Centauri, on three timescales, hours (plot A), days (plot B) and years (plot C). Adapted from Patterson ''et al.'' (2000),<ref name=patterson/> Kato ''et al.'' (2004)<ref name="Kato"/> and Levitan ''et al.'' (2015)<ref name="Levitan"/> }} {{Starbox observe | epoch=J2000.0 | ra={{RA|13|23|44.54}}<ref name=dr3/> | dec={{DEC|-41|44|29.54}}<ref name=dr3/> | appmag_v=12.7 - 17.7<ref name=gcvs>{{cite journal |bibcode=2017ARep...61...80S |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 |date=2017 |volume=61 |issue=1 |page=80 |doi=10.1134/S1063772917010085 }}</ref> | constell=[[Centaurus]] }} {{Starbox character | class=pec<ref name="Elvius1975"/> | b-v=+0.1<ref name=elvius>{{cite journal|bibcode=1975A&A....44..117E|title=Variable blue object with a peculiar spectrum|journal=Astronomy and Astrophysics|volume=44|pages=117|last1=Elvius|first1=A.|year=1975}}</ref> | u-b=−0.9 - −1.0<ref name=elvius/> | variable=[[AM Canum Venaticorum star|AM CVn]]<ref name=solheim>{{cite journal|bibcode=2010PASP..122.1133S|title=AM CVn Stars: Status and Challenges|journal=Publications of the Astronomical Society of the Pacific|volume=122|issue=896|pages=1133–1163|last1=Solheim|first1=J.-E.|year=2010|doi=10.1086/656680|doi-access=free}}</ref> }} {{Starbox astrometry | radial_v= | prop_mo_ra=−3.907<ref name=dr3/> | prop_mo_dec=+11.978<ref name=dr3/> | parallax=3.4885 | p_error=0.0599 | parallax_footnote=<ref name=dr3>{{cite Gaia DR3|6137049739573759872}}</ref> | dist_pc= | dist_ly= | absmag_v=5.93<ref name=solheim/> }} {{Starbox detail | component1 = White dwarf | mass=0.8 - 1.2<ref name=solheim/> | radius= | luminosity= | temperature= | metal= | gravity= | rotation= | age= | component2 = Donor star | mass2=0.06 - 0.11<ref name=solheim/> | radius2= | luminosity2= | temperature2= | metal2= | gravity2= | rotation2= | age2= }} {{Starbox catalog | names= V803 Centauri, [[variable star designation|V803]] Cen, [[A Elvius|AE]]-1, [[2MASS]] J13234454-4144294, [[AAVSO]] 1317-41. }} {{Starbox reference | Simbad=V803+Cen }} {{Starbox end}}
'''V803 Centauri''' (V803 Cen) is a [[Cataclysmic variable star|cataclysmic]] binary consisting of a dwarf [[helium star]] losing mass to a white dwarf. It is an example of the [[AM Canum Venaticorum star|AM Canum Venaticorum]] (AM CVn) type of [[cataclysmic variable]] stars.<ref name=patterson/>
[[Aina Elvius|Aina Margareta Elvius]] announced the discovery of this star in 1975.<ref name="Elvius1975"/> It was given its [[variable star designation]], V803 Centauri, in 1978.<ref name="Kholopov1978"/> The [[light curve]] shows a "low state" at about magnitude 17, with rapid outbursts of several magnitudes lasting only a few days or brighter super-outbursts lasting a few weeks, and a "high state" at up to 13th magnitude. V803 Centauri is most often seen in the high state, where it may stay bright for a year or more.<ref name=duffy2021>{{cite journal |bibcode=2021MNRAS.502.4953D |title=Evidence that short-period AM CVN systems are diverse in outburst behaviour |last1=Duffy |first1=C. |last2=Ramsay |first2=G. |last3=Steeghs |first3=D. |last4=Dhillon |first4=V. |last5=Kennedy |first5=M. R. |last6=Mata Sánchez |first6=D. |last7=Ackley |first7=K. |last8=Dyer |first8=M. |last9=Lyman |first9=J. |last10=Ulaczyk |first10=K. |last11=Galloway |first11=D. K. |last12=O'Brien |first12=P. |last13=Noysena |first13=K. |last14=Nuttall |first14=L. |last15=Pollacco |first15=D. |journal=Monthly Notices of the Royal Astronomical Society |date=2021 |volume=502 |issue=4 |page=4953 |doi=10.1093/mnras/stab389 |doi-access=free |arxiv=2102.04428 }}</ref>
The donor star has been radically stripped of material and now only around {{solar mass|0.1|link=y}} remains. With its outer layers removed, the helium core has expanded and cooled and is almost impossible to detect directly. The accreting white dwarf has a temperature around {{val|fmt=commas|14,000|ul=K}}.<ref name=bildsten2006>{{cite journal |bibcode=2006ApJ...640..466B |title=The Thermal State of the Accreting White Dwarf in AM Canum Venaticorum Binaries |last1=Bildsten |first1=Lars |last2=Townsley |first2=Dean M. |last3=Deloye |first3=Christopher J. |last4=Nelemans |first4=Gijs |journal=The Astrophysical Journal |date=2006 |volume=640 |issue=1 |page=466 |doi=10.1086/500080 |arxiv=astro-ph/0510652 }}</ref> Most of the light from V803 Cen is produced by an accretion disk, especially when the system is in outburst. The accretion disk shows a blackbody temperature around {{val|fmt=commas|30,000|u=K}}.<ref name=sion2011>{{cite journal |bibcode=2011ApJ...741...63S |title=The Hot Components of AM CVN Helium Cataclysmics |last1=Sion |first1=Edward M. |last2=Linnell |first2=Albert P. |last3=Godon |first3=Patrick |last4=Ballouz |first4=Ronald-Louis |journal=The Astrophysical Journal |date=2011 |volume=741 |issue=1 |page=63 |doi=10.1088/0004-637X/741/1/63 |arxiv=1108.1388 }}</ref>
==References== <references> <ref name=patterson>{{cite journal |last1=Patterson |first1=Joseph |last2=Walker |first2=Stan |last3=Kemp |first3=Jonathan |last4=O'Donoghue |first4=Darragh |last5=Bos |first5=Marc |last6=Stubbings |first6=Rod |year=2000 |title=V803 Centauri: A Helium-rich Dwarf Nova |journal=Publications of the Astronomical Society of the Pacific |volume=112 |issue=771 |pages=625–631 |publisher=The University of Chicago Press on behalf of the Astronomical Society of the Pacific |jstor=316561 |doi=10.1086/316561|bibcode = 2000PASP..112..625P |doi-access=free }}</ref>
<ref name="Kholopov1978">{{cite journal |last1=Kholopov |first1=P. N. |last2=Kukarkina |first2=N. P. |last3=Perova |first3=N. B. |title=63rd Name-List of Variable Stars |journal=Information Bulletin on Variable Stars |bibcode=1978IBVS.1414....1K |date=April 1978 |volume=1414 |pages=1–10 |url=https://ibvs.konkoly.hu/pub/ibvs/1401/1414.pdf |access-date=16 January 2025}}</ref>
<ref name="Elvius1975">{{cite journal |last1=Elvius |first1=A. |title=Variable blur object with a peculiar spectrum |journal=Astronomy and Astrophysics |date=November 1975 |volume=44 |pages=117–121 |bibcode=1975A&A....44..117E }}</ref>
<ref name="Kato">{{cite journal |last1=Kato |first1=Taichi |last2=Stubbings |first2=Rod |last3=Monard |first3=Berto |last4=Butterworth |first4=Neil D. |last5=Bolt |first5=Greg |last6=Richards |first6=Tom |title=V803 Centauri: Helium Dwarf Nova Mimicking a WZ Sge-Type Superoutburst |journal=Publications of the Astronomical Society of Japan |date=March 25, 2004 |volume=56 |pages=S89–S98 |doi=10.1093/pasj/56.sp1.S89 |arxiv=astro-ph/0307308 |bibcode=2004PASJ...56S..89K |doi-access=free }}</ref>
<ref name="Levitan">{{cite journal |last1=Levitan |first1=David |last2=Groot |first2=Paul J. |last3=Prince |first3=Thomas A. |last4=Kulkarni |first4=Shrinivas R. |last5=Laher |first5=Russ |last6=Ofek |first6=Eran O. |last7=Sesar |first7=Branimir |last8=Surace |first8=Jason |title=Long-term photometric behaviour of outbursting AM CVn systems |journal=Monthly Notices of the Royal Astronomical Society |date=January 2015 |volume=446 |issue=1 |pages=391–410 |doi=10.1093/mnras/stu2105 |arxiv=1410.6987 |bibcode=2015MNRAS.446..391L |doi-access=free }}</ref> </references>
{{Stars of Centaurus}}
[[Category:Centaurus]] [[Category:Dwarf novae]] [[Category:Objects with variable star designations|Centauri, V803]] [[Category:AM CVn stars]] [[Category:White dwarfs]]