PV Telescopii
{{Short description|Star in the constellation Telescopium}}
{{Starbox begin}}
{{Starbox image
| image = 250px
| caption = A light curve for PV Telescopii, adapted from Jeffery et al. (2020)
}}
{{Starbox observe
| epoch = J2000
| dec = {{DEC|-56|37|44.1401}}
| appmag_v = 9.30 {{nowrap|(9.24 - 9.40)}}
| constell = Telescopium
}}
{{Starbox character
| type =
| variable = PV Tel
}}
{{Starbox astrometry
| parallax = 0.1162
| p_error = 0.0449
| dist_ly = {{val|23000|fmt=commas}}
| dist_pc =
{{val|7100|1400|2000|fmt=commas}}
}}
{{Starbox detail
| source =
| radius = {{val|27.20|4.09|7.26}}
| luminosity = {{val|24000|8600|9900|fmt=commas}}
| temperature = {{val|13750|400|fmt=commas}}
| rotational_velocity =
| age_myr =
}}
{{Starbox catalog
| names = {{odlist | V=PV Tel | HD=168476 | HIP=90099 | SAO=245434 | CD=−56°7300 | 2MASS=J18231466-5637441 }}, AAVSO 1814-56
}}
{{Starbox reference
| Simbad = PV+Tel
}}
{{Starbox end}}
PV Telescopii, also known as HD 168476, is a variable star in the southern constellation of Telescopium. It is too dim to be visible to the naked eye, having an apparent visual magnitude that has been measured varying from 9.24 down to 9.40. The star is the prototype of a class of objects called PV Telescopii variables. It is located at an estimated distance of approximately {{convert|7.1|kpc|kly|order=flip|abbr=off|lk=on}} from the Sun, but is drifting closer with a radial velocity of −169 km/s.
This is an extreme helium star that shows a highly-processed atmosphere. It is a blue-white hued B-type supergiant star with a peculiar spectrum that has "weak hydrogen lines and enhanced lines of He and C". This object may be a late thermal pulse post-AGB star or the result of a merger of two white dwarf stars. The star shows radial velocity changes thought to be due to radial pulsations caused by a strange mode instability. It shows variations over a few days, 8–10 days being typically quoted. Despite a mass thought to be less than the Sun, it is actually around 24,000 times more luminous.
References
{{reflist|refs=
{{Cite Gaia DR2|6649049591179768064}}
| title=PV Tel | access-date=2020-11-16 }}
| title=Merged binary white dwarf evolution: rapidly accreting carbon-oxygen white dwarfs and the progeny of extreme helium stars
| last1=Saio | first1=Hideyuki | last2=Jeffery | first2=C. Simon
| journal=Monthly Notices of the Royal Astronomical Society
| volume=333 | issue=1 | pages=121–132 | date=June 2002
| bibcode=2002MNRAS.333..121S | doi=10.1046/j.1365-8711.2002.05384.x | doi-access=free }}
| title=Variable Star Designations for Extreme Helium Stars
| last=Jeffery | first=C. Simon
| journal=Information Bulletin on Variable Stars
| volume=5817 | page=1 | date=March 2008
| bibcode=2008IBVS.5817....1J }}
| display-authors=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.
| title=General Catalogue of Variable Stars
| version=5.1 | journal=Astronomy Reports
| year=2017 | volume=61 | issue=1 | pages=80–88
| bibcode=2017ARep...61...80S | s2cid=125853869
| doi=10.1134/S1063772917010085 }}
| title=TESS photometry of extreme helium stars PV Tel and V821 Cen
| display-authors=1 | last1=Jeffery | first1=C. Simon
| last2=Barentsen | first2=Geert | last3=Handler | first3=Gerald
| journal=Monthly Notices of the Royal Astronomical Society: Letters
| volume=495 | issue=1 | pages=L135–L138 | date=April 2020
| arxiv=2006.00946 | bibcode=2020MNRAS.495L.135J
| doi=10.1093/mnrasl/slaa075 | doi-access=free }}
| title=On the angular momentum evolution of merged white dwarfs
| last1=Gourgouliatos | first1=K. N. | last2=Jeffery | first2=C. S.
| journal = Monthly Notices of the Royal Astronomical Society
| volume=371 | issue=3 | pages=1381–1389 | year=2006
| bibcode=2006MNRAS.371.1381G | arxiv=astro-ph/0607379
| doi=10.1111/j.1365-2966.2006.10780.x | doi-access=free | s2cid=10489476 }}
| title=Cyclic and secular variation in the temperatures and radii of extreme helium stars
| last1=Jeffery | first1=C. S.| last2=Starling | first2=R. L. C.
| last3=Hill | first3=P. W. | last4=Pollacco | first4=D.
| display-authors=1 | journal=Monthly Notices of the Royal Astronomical Society
| volume=321 | issue=1 | pages=111–130 | year=2001
| bibcode=2001MNRAS.321..111J | citeseerx=10.1.1.29.1648
| doi=10.1046/j.1365-8711.2001.03992.x | doi-access=free }}
| title=VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system
| journal=CDS/ADC Collection of Electronic Catalogues
| last1=Ducati | first1=J. R.
| volume=2237 | year=2002
| bibcode=2002yCat.2237....0D }}
| title=Radial velocities for the hydrogen-deficient star HD 168476, several helium-strong and helium-weak stars
| last1=Walker | first1=H. J. | last2=Hill | first2=P. W.
| journal=Astronomy and Astrophysics Supplement Series
| volume=61 | pages=303 | year=1985
| bibcode=1985A&AS...61..303W }}
| title=Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system
| last=Gontcharov | first=G. A.
| journal=Astronomy Letters
| volume=32 | issue=11 | pages=759–771 | year=2006
| bibcode=2006AstL...32..759G | arxiv=1606.08053
| doi=10.1134/S1063773706110065 | s2cid=119231169 }}
| title=Colours and effective temperatures of extreme helium stars
| journal=Astronomy and Astrophysics
| last1=Heber | first1=U. | last2=Schoenberner | first2=D.
| volume=102 | pages=73 | year=1981
| bibcode=1981A&A...102...73H }}
| title=The PASTEL catalogue of stellar parameters
| last1=Soubiran | first1=C.| last2=Le Campion | first2=J. -F.
| last3=Cayrel De Strobel | first3=G.| last4=Caillo | first4=A.
| journal=Astronomy and Astrophysics
| volume=515 | pages=A111 | year=2010
| bibcode=2010A&A...515A.111S | arxiv=1004.1069
| doi=10.1051/0004-6361/201014247 | s2cid=118362423 }}
| title=Neon and CNO Abundances for Extreme Helium Stars—A Non-LTE Analysis
| last1=Pandey | first1=Gajendra | last2=Lambert | first2=David L.
| journal=The Astrophysical Journal
| volume=727 | issue=2 | pages=122 | year=2011
| bibcode=2011ApJ...727..122P | arxiv=1011.5035
| doi=10.1088/0004-637X/727/2/122 | s2cid=118621588}}
}}
{{Stars of Telescopium}}
{{DEFAULTSORT:PV Telescopii}}
Category:PV Telescopii variables