12 Lacertae

Star in the constellation Lacerta 250px A light curve for DD Lacertae, plotted from TESS data J2000 Lacerta 22 41 28.64951 +40 13 31.6097 5.228 B1.5III −0.142 β Cep −12.5 2.2 −2.005 0.150 −4.512 0.117 2.5877 0.1327 −3.02 9.5 0.3 8.4 23809 450 commas 8,877 44 6 3.817 0.047 −0.41 21.8 3.1 12 Lac DD Lac +39°4912 31670 214993 112031 8640 72627 J22415+4014A 12+Lac 12 Lacertae is a wide binary star system in the northern constellation of Lacerta, located roughly 1,260 light years away from the Sun based on parallax. It is visible to the naked eye as a dim, blue-white hued point of light with a baseline apparent visual magnitude of 5.23. The system is drifting closer to the Earth with a mean heliocentric radial velocity of –12.5. It is a probable member of the I Lacertae OB association (Lac OB1). The primary component is a Beta Cephei variable with a stellar classification of B1.5III, matching a B-type star with the luminosity class of a giant star. It has been known to be variable for more than a century and has been extensively studied. The variable radial velocity of the star was discovered by W. S. Adams in 1912, and the light variations were established by 1919. The pulsational nature of the variability was shown by P. Ledoux in 1951, which led to one of the first world-wide observing campaigns with the star as its target. Dutch mathematician F. J. M. Barning analyzed the resulting data in 1963 and found four separate cycles of variation. By 1994, six periods had been confirmed. The variable star designation of the primary is DD Lacertae, while 12 Lacertae is the Flamsteed designation. In general terms it varies in magnitude from 5.16 down to 5.28 with a period of 0.1930924 days hours 2 out off. As many as eleven different frequencies have been detected, with the dominant cycle showing a frequency of 5.179034 cycles per day. Three of the frequencies form an equally-spaced triplet with cycles of 5.179, 5.334, and 5.490 per day, although this alignment appears to be a coincidence. It is a hybrid pulsator, showing mixed behaviors of a Beta Cephei variable and a slowly pulsating B-type star. The primary is a massive star, having 9.5 times the mass of the Sun and an age of only 22 million years old. It has about 8.4 times the girth of the Sun. The averaged quadratic field strength of the surface magnetic field is 2352.3 1604.9 −4 T commas. It is radiating 8,877 times the luminosity of the Sun from its photosphere at an effective temperature of 23,809 K. The estimated rotational velocity of the primary at the equator is 52 5 km/s; about 10% of its break-up velocity. However, seismic models suggest the core region is rotating much more rapidly with a rotational velocity of up to 100 km/s, and thus the star is undergoing differential rotation. The companion is an A-type main-sequence star with a stellar classification of A3V and visual magnitude 9.2. As of 2008, it had an angular separation of 69 arcsecond from the primary. There is a faint infrared nebulosity at a separation of 0.19 pc ly 1 out off from the pair that is most likely a bow shock. References MAST: Barbara A. Mikulski Archive for Space Telescopes https://mast.stsci.edu/portal/Mashup/Clients/Mast/Portal.html Space Telescope Science Institute 8 December 2021 12 Lac 2019-06-27 1932278646577186688 Lacerta OB1 Revisited . Kaltcheva Nadia Publications of the Astronomical Society of the Pacific 121 884 1045–1053 October 2009 10.1086/606037 2009PASP..121.1045K 120329065 free 1 Tetzlaff N. Neuhäuser R. Hohle M. M. A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun Monthly Notices of the Royal Astronomical Society 410 1 190–200 January 2011 10.1111/j.1365-2966.2010.17434.x free 2011MNRAS.410..190T . 1007.4883 118629873 Lefever K. Puls J. Morel T. Aerts C. Decin L. Briquet M. Spectroscopic determination of the fundamental parameters of 66 B-type stars in the field-of-view of the CoRoT satellite Astronomy and Astrophysics 1 515 A74 June 2010 2010A&A...515A..74L 0910.2851 10.1051/0004-6361/200911956 54028925 . Hohle M. M. Neuhäuser R. Schutz B. F. Masses and luminosities of O- and B-type stars and red supergiants Astronomische Nachrichten 331 4 349–360 2010 2010AN....331..349H . 10.1002/asna.200911355 1003.2335 111387483 An asteroseismic study of the β Cephei star 12 Lacertae: multisite spectroscopic observations, mode identification and seismic modelling 1 Desmet M. Briquet M. Thoul A. Zima W. De Cat P. Handler G. Ilyin I. Kambe E. Krzesinski J. Lehmann H. Masuda S. Mathias P. Mkrtichian D. E. Telting J. Uytterhoeven K. Yang S. L. S. Aerts C. Monthly Notices of the Royal Astronomical Society 396 3 1460–1472 July 2009 10.1111/j.1365-2966.2009.14790.x free 0903.5477 2009MNRAS.396.1460D 53526744 . Eggleton P. P. Tokovinin A. A. A catalogue of multiplicity among bright stellar systems Monthly Notices of the Royal Astronomical Society 389 2 869–879 September 2008 10.1111/j.1365-2966.2008.13596.x free 0806.2878 2008MNRAS.389..869E 14878976 . Internal motions in the associations II Per and I Lac. Lesh J. R. . Astronomical Journal 74 891–898 September 1969 10.1086/110878 1969AJ.....74..891L Asteroseismology of the β Cephei star 12 (DD) Lacertae: photometric observations, pulsational frequency analysis and mode identification 1 Handler G. Jerzykiewicz M. Rodríguez E. Uytterhoeven K. Amado P. J. Dorokhova T. N. Dorokhov N. I. Poretti E. Sareyan J. -P. Parrao L. Lorenz D. Zsuffa D. Drummond R. Daszyńska-Daszkiewicz J. Verhoelst T. De Ridder J. Acke B. Bourge P. -O. Movchan A. I. Garrido R. Paparó M. Sahin T. Antoci V. Udovichenko S. N. Csorba K. Crowe R. Berkey B. Stewart S. Terry D. Mkrtichian D. E. Aerts C. Monthly Notices of the Royal Astronomical Society 365 1 327–338 January 2006 10.1111/j.1365-2966.2005.09728.x free astro-ph/0510326 2006MNRAS.365..327H 122766497 . . Lesh Janet Rountree The Kinematics of the Gould Belt: an Expanding Group? Astrophysical Journal Supplement 17 371 December 1968 10.1086/190179 1968ApJS...17..371L free A Stellar Rotation Census of B Stars: From ZAMS to TAMS 1 Huang W. Gies D. R. McSwain M. V. The Astrophysical Journal 722 1 605–619 2010 2010ApJ...722..605H . 10.1088/0004-637X/722/1/605 1008.1761 118532653 Rotational Velocities for B0-B3 Stars in Seven Young Clusters: Further Study of the Relationship between Rotation Speed and Density in Star-Forming Regions Wolff S. C. Strom S. E. Dror D. Venn K. The Astronomical Journal 133 3 1092–1103 March 2007 10.1086/511002 astro-ph/0702133 2007AJ....133.1092W 119074863 . Anderson E. Francis Ch. XHIP: An extended hipparcos compilation Astronomy Letters 38 5 331 2012 2012AstL...38..331A 1108.4971 10.1134/S1063773712050015 119257644 . The two hybrid B-type pulsators: ν Eridani and 12 Lacertae Dziembowski W. A. Pamyatnykh A. A. Monthly Notices of the Royal Astronomical Society 385 4 2061–2068 April 2008 10.1111/j.1365-2966.2008.12964.x free . 2008MNRAS.385.2061D 0801.2451 16027828 General catalogue of variable stars 5.1 Samus' N. N Kazarovets E. V Durlevich O. V Kireeva N. N Pastukhova E. N Astronomy Reports 61 1 80 2017 . 10.1134/S1063772917010085 2017ARep...61...80S 125853869 The β Cep/SPB star 12 Lacertae: extended mode identification and complex seismic modelling 1 Daszyńska-Daszkiewicz J. Szewczuk W. Walczak P. Monthly Notices of the Royal Astronomical Society 431 4 3396–3407 June 2013 10.1093/mnras/stt418 free 1304.4049 2013MNRAS.431.3396D 118524387 . 1 Bychkov V. D. Bychkova L. V. Madej J. Catalogue of averaged stellar effective magnetic fields. I. Chemically peculiar A and B type stars Astronomy and Astrophysics 407 2 631–642 August 2003 10.1051/0004-6361:20030741 2003A&A...407..631B astro-ph/0307356 14184105 . 1 Pasinetti Fracassini L. E. Pastori L. Covino S. Pozzi A. Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS) Third Astronomy and Astrophysics 367 521–524 February 2001 10.1051/0004-6361:20000451 2001A&A...367..521P astro-ph/0012289 425754 . Infrared nebulae around bright massive stars as indicators for binary interactions Bodensteiner J. Baade D. Greiner J. Langer N. 1 Astronomy & Astrophysics 618 A110 13 October 2018 10.1051/0004-6361/201832722 1806.01294 2018A&A...618A.110B 118972162 . Gies Douglas R. Lambert David L. Carbon, nitrogen, and oxygen abundances in early B-type stars Astrophysical Journal, Part 1 387 673–700 March 1992 10.1086/171116 1992ApJ...387..673G free Category:B-type giants Category:Beta Cephei variables Category:Slowly pulsating B-type stars Category:A-type main-sequence stars Category:Binary stars Category:Lacerta BD+39 4912 Lacertae, 12 214993 112031 8640 Lacertae, DD