Variable star in the constellation Cassiopeia
Pi Cassiopeiae is a closebinary star [ 8] constellation Cassiopeia , near the southern border withAndromeda . Its name is aBayer designation that isLatinized from π Cassiopeiae, and abbreviated Pi Cas or π Cas. This system is visible to thenaked eye as a point of light with a combinedapparent visual magnitude of +4.949.[ 3] parallax shift ofmas [ 2] light-years (54 pc ) 175 light years from theSun . It is drifting further away with aradial velocity of +13 km/s.[ 7]
Alight curve for Pi Cassiopeiae, plotted fromTESS [ 12] This is a double-linedspectroscopic binary system with anorbital period of nearly two days in a circular orbit.[ 8] rotating ellipsoidal variable star and its brightness varies by 0.02 magnitudes with a period of 23.57 hours,[ 6] spectrum matches that of anA-type main-sequence star with astellar classification of A5 V.[ 4] [ 5] AU white dwarf . It is at the same distance as Pi Cassiopeiae and shares acommon proper motion . The age of the white dwarf is calculated to be about 500 million years.[ 13]
Pi Cassiopeiae has been given the spectral class of kA3hF1mA5, indicating anAm star ,[ 14] [ 15]
^a b Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation",Astronomy Letters 38 (5): 331,arXiv :1108.4971 Bibcode :2012AstL...38..331A ,doi :10.1134/S1063773712050015 . XHIP record for this object atVizieR .^a b c d e f g Vallenari, A.; et al. (Gaia collaboration) (2023),"Gaia Data Release 3. Summary of the content and survey properties" ,Astronomy and Astrophysics ,674 : A1,arXiv :2208.00211 Bibcode :2023A&A...674A...1G ,doi :10.1051/0004-6361/202243940 S2CID 244398875 . Gaia DR3 record for this source atVizieR .^a b c Høg, E.; et al. (2000), "The Tycho-2 catalogue of the 2.5 million brightest stars",Astronomy and Astrophysics ,355 : L27,Bibcode :2000A&A...355L..27H ,doi :10.1888/0333750888/2862 . ^a b Cowley, A.; et al. (April 1969), "A study of the bright A stars. I. A catalogue of spectral classifications",Astronomical Journal ,74 :375– 406,Bibcode :1969AJ.....74..375C ,doi :10.1086/110819 . ^a b c d e f Howe, K. S.; Clarke, C. J. (2009), "An analysis of v sin (I) correlations in early-type binaries",Monthly Notices of the Royal Astronomical Society ,392 (1): 448,Bibcode :2009MNRAS.392..448H ,doi :10.1111/j.1365-2966.2008.14073.x S2CID 120183969 . ^a b Samus, N. N.; et al. (2017), "General Catalogue of Variable Stars",Astronomy Reports , GCVS 5.1,61 (1):80– 88,Bibcode :2017ARep...61...80S ,doi :10.1134/S1063772917010085 ,S2CID 125853869 . ^a b de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project",Astronomy & Astrophysics ,546 : 14,arXiv :1208.3048 Bibcode :2012A&A...546A..61D ,doi :10.1051/0004-6361/201219219 ,S2CID 59451347 , A61. ^a b c Pourbaix, D.; et al. (2004), "SB9: The Ninth Catalogue of Spectroscopic Binary Orbits",Astronomy & Astrophysics ,424 :727– 732,arXiv :astro-ph/0406573 Bibcode :2004A&A...424..727P ,doi :10.1051/0004-6361:20041213 ,S2CID 119387088 . ^ McDonald, I.; et al. (2012), "Fundamental Parameters and Infrared Excesses of Hipparcos Stars",Monthly Notices of the Royal Astronomical Society ,427 (1):343– 57,arXiv :1208.2037 Bibcode :2012MNRAS.427..343M ,doi :10.1111/j.1365-2966.2012.21873.x S2CID 118665352 . ^a b c David, Trevor J.; Hillenbrand, Lynne A. (2015), "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets",The Astrophysical Journal ,804 (2): 146,arXiv :1501.03154 Bibcode :2015ApJ...804..146D ,doi :10.1088/0004-637X/804/2/146 ,S2CID 33401607 . ^ "pi. Cas" ,SIMBAD Centre de données astronomiques de Strasbourg , retrieved2017-08-30 .^ MAST: Barbara A. Mikulski Archive for Space Telescopes , retrieved8 December 2021 .^ Qiu, Dan; et al. (2021), "Precise Ages of Field Stars from White Dwarf Companions in Gaia DR2",The Astrophysical Journal Supplement Series ,253 (2): 58,arXiv :2012.04890 Bibcode :2021ApJS..253...58Q ,doi :10.3847/1538-4365/abe468 S2CID 234867350 . ^ Abt, Helmut A.; Morrell, Nidia I. (1995), "The Relation between Rotational Velocities and Spectral Peculiarities among A-Type Stars",Astrophysical Journal Supplement Series ,99 : 135,Bibcode :1995ApJS...99..135A ,doi :10.1086/192182 ^ Renson, P.; Manfroid, J. (2009), "Catalogue of Ap, HGMN and Am stars",Astronomy and Astrophysics ,498 (3): 961,Bibcode :2009A&A...498..961R ,doi :10.1051/0004-6361/200810788
