CP Lacertae
Location of CP Lacertae (circled in red)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Lacerta
Right ascension 22h 15m 41.103s[1]
Declination +55° 37′ 01.44″[1]
Apparent magnitude (V) 2.1 Max.
16.6 Min.[2]
Characteristics
Variable type Nova[2]
Astrometry
Distance3,800+220
−160 ly
(1170+67
−50 [3] pc)
Other designations
Nova Lac 1936, AAVSO 2212+55, 2MASS J22154108+5537014[4]
Database references
SIMBADdata
The light curve of CP Lacertae plotted from AAVSO data

CP Lacertae (also known as Nova Lacertae 1936 or CP Lac) was a nova, which lit up on June 18, 1936 in the constellation Lacerta. It was discovered independently by several observers including Leslie Peltier in the US, E. Loreta in Italy, and Kazuaki Gomi, a Japanese barber who discovered the nova during the 19 June 1936 total solar eclipse.[5]

The nova reached a peak brightness of 2.1 mag,[6] making it readily visible to the naked eye during night time. Following the outbreak, the brightness of CP Lacertae decreased thereafter, falling 3 magnitudes after nine days. It is classified as a very fast nova, with a smooth light curve.[7][8]

Located at an estimated distance of 3.8 kly (1.17 kpc),[3] this is a close binary system with a degenerate white dwarf primary in orbit with a cool red dwarf secondary over a period of 0.145143 days.[9] Matter from the red dwarf is being drawn off onto an accretion disk orbiting the white dwarf. The mean brightness of the system varies with an amplitude of 0.5 magnitude from day to day. The observational data shows a general period of 0.037 days, which may be related to the rotation period of the white dwarf component.[10]

Unlike many novae, CP Lacertae does not have a shell visible as a nebula with optical telescopes.[11]

References

  1. ^ a b Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  2. ^ 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.
  3. ^ a b Schaefer, Bradley E. (20 September 2018). "The distances to Novae as seen by Gaia". Monthly Notices of the Royal Astronomical Society. 481 (3): 3033–3051. arXiv:1809.00180. Bibcode:2018MNRAS.481.3033S. doi:10.1093/mnras/sty2388.
  4. ^ Cutri, R. M.; et al. (June 2003), "2MASS All Sky Catalog of point sources", The IRSA 2MASS All-Sky Point Source Catalog, NASA/IPAC, Bibcode:2003tmc..book.....C.
  5. ^ Warner, B. (February 2006). "Where have all the novae gone?". Astronomy & Geophysics. 47 (1): 29–32. Bibcode:2006A&G....47a..29W. doi:10.1111/j.1468-4004.2006.47129.x.
  6. ^ Howarth, I. D. (October 1978), "CP Lacertae (Nova 1936)", Journal of the British Astronomical Association, 88: 608–618, Bibcode:1978JBAA...88..608H.
  7. ^ Rodríguez-Gil, P.; Torres, M.A.P. (February 2005). "Time-resolved photometry of the nova remnants DM Gem, CP Lac, GI Mon, V400 Per, CT Ser and XX Tau" (PDF). Astronomy & Astrophysics. 431: 289–296. arXiv:astro-ph/0410348. doi:10.1051/0004-6361:20041112. Retrieved 6 December 2020.
  8. ^ Tappert, C.; Vogt, N.; Ederoclite, A.; Schmidtobreick, L.; Vuckovic, M.; Becegato, L.L. (September 2020). "The luminosity evolution of nova shells. I. A new analysis of old data". Astronomy & Astrophysics. 641: A122. arXiv:2007.10940. Bibcode:2020A&A...641A.122T. doi:10.1051/0004-6361/202037913.
  9. ^ Pavlenko, E. P.; et al. (May 2007), "The Photometric Study of Nova Lacertae 1936 = CP Lac Between 2003 – 2005", in Demircan, O.; Selam, S. O.; Albayrak, B. (eds.), Solar and Stellar Physics Through Eclipses ASP Conference Series, Vol. 370, proceedings of the conference held 27–29 March, 2006 at Ankara University, ÖRSEM Campus, Side, Antalya, Turkey, vol. 370, Astronomical Society of the Pacific, p. 324, Bibcode:2007ASPC..370..324P.
  10. ^ Litvinchova, A. A.; Pavlenko, E. P. (December 2010), "The Photometric Investigation of the Active Post-Nova CP Lac in High and Low State of Brightness in 2006–2008 yrs", Odessa Astronomical Publications, 23: 76, Bibcode:2010OAP....23...76L.
  11. ^ Sahman, D.I.; Dhillon, V.S.; Knigge, C.; Marsh, T.R. (August 2015). "Searching for nova shells around cataclysmic variables". Monthly Notices of the Royal Astronomical Society. 451 (3): 2863–2876. arXiv:1505.06048. doi:10.1093/mnras/stv1150.
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