DI Lacertae


DI Lacertae
Location of DI Lacertae (circled in red)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Lacerta
Right ascension 22h 35m 48.495s[1]
Declination 52° 42′ 59.64″[1]
Apparent magnitude (V) 4.6v — 14.9p[2]
[3] pc
Variable type Nova
Other designations
Nova Lac 1910, DI Lac, HD 214239, AAVSO 2231+52, Gaia DR2 2002212087238591488
Database references
The light curve of nova DI Lacertae, plotted from data presented by Shapley. If multiple measurements with identical times were reported, they were averaged before plotting[4] The red pre-eruption point is from Robinson.[5]

DI Lacertae or Nova Lacertae 1910 was a nova in constellation Lacerta which appeared in 1910. It was discovered by Thomas Henry Espinell Compton Espin at Wolsingham Observatory on 30 Dec 1910, at which time it was an 8th magnitude object. Subsequent examination of pre-discovery photographic plates showed that the outburst occurred sometime between 17 November 1910 and 23 November 1910.[6] It reached a peak brightness of magnitude 4.6 on 26 November 2021, making it visible to the naked eye.[3] Before the nova event DI Lacertae was a 14th magnitude star,[7] and by 1950 it had returned to 14th magnitude.[8]

DI Lacertae dropped from peak brightness by 3 magnitudes in just 43 days, making it a "fast nova".[9][10]

All novae are binary stars, with a "donor" star orbiting a white dwarf. The two stars are so close to each other that matter is transferred from the donor star to the white dwarf. In the case of DI Lacertae, the oribital period for the binary pair is 13.050 hours, which is unusually long for a nova.[11] The mass of the white dwarf has been estimated to be 0.91±0.2M In 2017 Sion et al. presented analysis of ultraviolet spectra from the Far Ultraviolet Spectroscopic Explorer and International Ultraviolet Explorer spacecraft, and found the best fit for DI Lacertae to be an accretion disk with a mass accretion rate of 10−10M per year with a 30,000 Kelvin white dwarf.[12] Darnley et al. argue that the donor star is probably a main sequence star or, less probably, a subdwarf.[11]


  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. ^ Downes, Ronald; Webbink, Ronald F.; Shara, Michael M. (April 1997). "A Catalog and Atlas of Cataclysmic Variables-Second Edition". Publications of the Astronomical Society of the Pacific. 109: 345. doi:10.1086/133900. Retrieved 22 December 2020.
  3. ^ a b Selvelli, Pierluigi; Gilmozzi, Roberto (February 2019). "A UV and optical study of 18 old novae with Gaia DR2 distances: mass accretion rates, physical parameters, and MMRD". Astronomy & Astrophysics. 622: A186. arXiv:1903.05868. Bibcode:2019A&A...622A.186S. doi:10.1051/0004-6361/201834238. Retrieved 24 December 2020.
  4. ^ Shapley, Harlow (January 1933). "The photographic light curves of 11 novae". Annals of the Astronomical Observatory of Harvard College. 84 (5): 121–155. Bibcode:1933AnHar..84..121S. Retrieved 22 January 2021.
  5. ^ Robinson, E.L. (July 1975). "Preeruption light curves of novae". Astronomical Journal. 80: 515–524. Bibcode:1975AJ.....80..515R. doi:10.1086/111774. Retrieved 22 January 2021.
  6. ^ Duerbeck, Hilmar W. (March 1987). "A Reference Catalogue and Atlas of Galactic Novae". Space Science Reviews. 45 (1–2): 1–14. Bibcode:1987SSRv...45....1D. doi:10.1007/BF00187826. S2CID 115854775. Retrieved 24 December 2020.
  7. ^ Frost, E. B. (1911). "Observations of Nova Lacertae at the Yerkes Observatory". The Astrophysical Journal. 33: 410–417. Bibcode:1911ApJ....33..410F. doi:10.1086/141865.
  8. ^ Steavenson, W.H. (January 1953). "Observations of novae, 1950, 1951 and 1952". Monthly Notices of the Royal Astronomical Society. 113 (2): 258. Bibcode:1953MNRAS.113..258S. doi:10.1093/mnras/113.2.258. Retrieved 24 December 2020.
  9. ^ Marin, E.; Shafter, A.W. (October 2009). "The Orbital Period of V368 Aquilae (Nova Aquilae 1936 No. 2". Publications of the Astronomical Society of the Pacific. 121 (884): 1090. arXiv:0908.3703. Bibcode:2009PASP..121.1090M. doi:10.1086/644647. S2CID 119192314.
  10. ^ Ritter, H.; Kolb, U. (June 2003). "Catalogue of cataclysmic binaries, low-mass X-ray binaries and related objects (Seventh edition)". Astronomy and Astrophysics. 404: 301–303. arXiv:astro-ph/0301444. Bibcode:2003A&A...404..301R. doi:10.1051/0004-6361:20030330. Retrieved 24 December 2020.
  11. ^ a b Darnley, M.J.; Ribeiro, V.A.R.M.; Bode, M.F.; Hounsell, R.A.; Williams, R.P. (February 2012). "On the Progenitors of Galactic Novae". The Astrophysical Journal. 746 (1): 61. arXiv:1112.2589. Bibcode:2012ApJ...746...61D. doi:10.1088/0004-637X/746/1/61. S2CID 119291027. Retrieved 24 December 2020.
  12. ^ Sion, Edward M.; et al. (2017). "Far Ultraviolet Spectroscopy of Old Novae. II. RR Pic, V533 Her, and DI Lac". The Astronomical Journal. 153 (3). 109. arXiv:1701.05218. Bibcode:2017AJ....153..109S. doi:10.3847/1538-3881/153/3/109. PMC 5810142. PMID 29456254.