PV Telescopii variable is a type of variable star that is established in the General Catalogue of Variable Stars with the acronym PVTEL. This class of variables are defined as "helium supergiant Bp stars with weak hydrogen lines and enhanced lines of He and C".[2] That is, the hydrogen spectral lines of these stars are weaker than normal for a star of stellar class B, while the lines of helium and carbon are stronger. They are a type of extreme helium star.
A light curve for PV Telescopii, adapted from Jeffery et al. (2020)[1]
The prototype for this category of variable is PV Telescopii, which undergoes small but complex luminosity variations and radial velocity fluctuations.[3] The PV Tel stars are extremely hydrogen-deficient compared to other B-class stars and vary in luminosity on time scales ranging from a few hours to several years.[4] As of 2008, there are twelve confirmed PV Tel variables in the General Catalogue of Variable Stars.[2]
PV Telescopii variables are subdivided into three distinct types on the basis of spectral type: type I represents late B and A stars, type II represents O and early B, and type III represents F and G stars. The type III stars are always carbon-rich and hydrogen-deficient, while the type I and II stars do not necessarily have an excess of carbon. The hotter types pulsate more quickly than the cooler types.[5]
Listedit
The following list contains selected PV Telescopii variable that are of interest to amateur or professional astronomy. Unless otherwise noted, the given magnitudes are in the V-band.[citation needed]
^Jeffery, C. Simon; Barentsen, Geert; Handler, Gerald (June 2020). "TESS photometry of extreme helium stars PV Tel and V821 Cen". Monthly Notices of the Royal Astronomical Society. 495 (1): L135–L138. arXiv:2006.00946. Bibcode:2020MNRAS.495L.135J. doi:10.1093/mnrasl/slaa075.
^ abJeffery, C. Simon (March 2008). "Variable Star Designations for Extreme Helium Stars". Information Bulletin on Variable Stars. 5817 (1). Bibcode:2008IBVS.5817....1J.
^Walker, H. J.; Hill, P. W. (August 1985). "Radial velocities for the hydrogen-deficient star HD 168476, several helium-strong and helium-weak stars". Astronomy and Astrophysics Supplement Series. 61: 303–311. Bibcode:1985A&AS...61..303W.
^Jeffery, C. S.; Heber, U. (July 1992). "The extreme helium star BD-9 deg 4395". Astronomy and Astrophysics. 260 (1–2): 133–150. Bibcode:1992A&A...260..133J.
telescopii, variable, type, variable, star, that, established, general, catalogue, variable, stars, with, acronym, pvtel, this, class, variables, defined, helium, supergiant, stars, with, weak, hydrogen, lines, enhanced, lines, that, hydrogen, spectral, lines,. PV Telescopii variable is a type of variable star that is established in the General Catalogue of Variable Stars with the acronym PVTEL This class of variables are defined as helium supergiant Bp stars with weak hydrogen lines and enhanced lines of He and C 2 That is the hydrogen spectral lines of these stars are weaker than normal for a star of stellar class B while the lines of helium and carbon are stronger They are a type of extreme helium star A light curve for PV Telescopii adapted from Jeffery et al 2020 1 The prototype for this category of variable is PV Telescopii which undergoes small but complex luminosity variations and radial velocity fluctuations 3 The PV Tel stars are extremely hydrogen deficient compared to other B class stars and vary in luminosity on time scales ranging from a few hours to several years 4 As of 2008 there are twelve confirmed PV Tel variables in the General Catalogue of Variable Stars 2 PV Telescopii variables are subdivided into three distinct types on the basis of spectral type type I represents late B and A stars type II represents O and early B and type III represents F and G stars The type III stars are always carbon rich and hydrogen deficient while the type I and II stars do not necessarily have an excess of carbon The hotter types pulsate more quickly than the cooler types 5 List editThe following list contains selected PV Telescopii variable that are of interest to amateur or professional astronomy Unless otherwise noted the given magnitudes are in the V band citation needed Star Maximummagnitude Minimummagnitude Type SpectraltypeUpsilon Sagittarii 4 43 4 65 I n 1 F2pHD 182040 6 95 7 17 III C HM Librae 7 42 7 63 III CKS Persei 7 60 7 85 I A5IapPV Telescopii 9 24 9 40 I B5pBD 1 4381 9 47 9 60 I FCD 35 11760 9 62 9 83 I B4IbeHD 160641 9 78 10 08 II sdOC9 5II III He40DN Leonis 9 91 10 00 II BpHD 124448 9 94 10 03 II B3pNO Serpentis 10 27 10 39 I BV1920 Cygni 10 30 10 41 I B2 3CPD 58 2721 10 40 10 60 I B BD 9 4395 10 44 10 63 II BLS IV 1 2 10 95 11 05 I OB Notes edit also a spectroscopic binary possibly eclipsingReferences edit Jeffery C Simon Barentsen Geert Handler Gerald June 2020 TESS photometry of extreme helium stars PV Tel and V821 Cen Monthly Notices of the Royal Astronomical Society 495 1 L135 L138 arXiv 2006 00946 Bibcode 2020MNRAS 495L 135J doi 10 1093 mnrasl slaa075 a b Jeffery C Simon March 2008 Variable Star Designations for Extreme Helium Stars Information Bulletin on Variable Stars 5817 1 Bibcode 2008IBVS 5817 1J Walker H J Hill P W August 1985 Radial velocities for the hydrogen deficient star HD 168476 several helium strong and helium weak stars Astronomy and Astrophysics Supplement Series 61 303 311 Bibcode 1985A amp AS 61 303W Jeffery C S Heber U July 1992 The extreme helium star BD 9 deg 4395 Astronomy and Astrophysics 260 1 2 133 150 Bibcode 1992A amp A 260 133J Otero S A Watson C Wils P Variable Star Type Designations in the VSX AAVSO Website American Association of Variable Star Observers Retrieved 19 July 2014 Retrieved from https en wikipedia org w index php title PV Telescopii variable amp oldid 1155050917, wikipedia, wiki, book, books, library,
