T Coronae Borealis

T Coronae Borealis
Observation data
Epoch J2000      Equinox J2000
Constellation Corona Borealis
Right ascension 15h 59m 30.1622s[1]
Declination 25° 55 12.613[1]
Apparent magnitude (V) 2.0–10.8[2]
Characteristics
Evolutionary stage Red giant + white dwarf
Spectral type M3III+p[3]
Variable type recurrent nova[2]
Astrometry
Radial velocity (Rv)27.79[4] km/s
Parallax (π)1.33 ± 0.57[1] mas
Distanceapprox. 2,000 ly
(approx. 800 pc)
Orbit
Period (P)228[5] yr
Eccentricity (e)0.0[5]
Inclination (i)67[6]°
Details
Giant
Mass0.8[7] M
Surface gravity (log g)2.0[8] cgs
Temperature3,600[8] K
White dwarf
Mass1.2[7] M
Luminosity40[7] L
Other designations
BD+26° 2765, HD 143454, HIP 78322, SAO 84129, 2MASS J15593015+2555126
Database references
SIMBADdata

T Coronae Borealis (T CrB), is a recurring nova in the constellation Corona Borealis. It was first discovered in outburst in 1866 by John Birmingham,[9] although it had been observed earlier as a 10th magnitude star.[10]

Description

AAVSO light curve of recurrent nova T CrB from 1 Jan 2008 to 17 Nov 2010, showing the pulsations of the red giant primary. Up is brighter and down is fainter. Day numbers are Julian day.

T CrB normally has an magnitude of about 10, which is near the limit of typical binoculars. It has been seen to outburst twice, reaching magnitude 2.0 on May 12, 1866 and magnitude 3.0 on February 9, 1946.[11] Though a more recent paper shows the 1866 outburst with a possible peak range of magnitude 2.5 ± 0.5.[12] Even when at peak magnitude of 2.5, this recurrent nova is dimmer than about 120 stars in the night sky.[13] It is sometimes nicknamed the Blaze Star,[14]

2016-present Activity

On 20 April 2016, the Sky and Telescope newsletter reported a recent sustained brightening since February 2015 from magnitude 10.5 to about 9.2. A similar event was reported in 1938, shortly before the 1946 outburst.[15] As of June 2018, the star has dimmed slightly but still remains at an unusually high level of activity.

References

  1. 1 2 3 Gaia Collaboration; et al. (November 2016). "Gaia Data Release 1. Summary of the astrometric, photometric, and survey properties". Astronomy & Astrophysics. 595: 23. arXiv:1609.04172. Bibcode:2016A&A...595A...2G. doi:10.1051/0004-6361/201629512. A2.
  2. 1 2 Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/gcvs. Originally published in: 2009yCat....102025S. 1. Bibcode:2009yCat....102025S.
  3. Shenavrin, V. I.; Taranova, O. G.; Nadzhip, A. E. (2011). "Search for and study of hot circumstellar dust envelopes". Astronomy Reports. 55: 31. Bibcode:2011ARep...55...31S. doi:10.1134/S1063772911010070.
  4. Pourbaix, D.; Tokovinin, A. A.; Batten, A. H.; Fekel, F. C.; Hartkopf, W. I.; Levato, H.; Morrell, N. I.; Torres, G.; Udry, S. (2004). "SB9: The ninth catalogue of spectroscopic binary orbits". Astronomy and Astrophysics. 424 (2): 727. arXiv:astro-ph/0406573. Bibcode:2004A&A...424..727P. doi:10.1051/0004-6361:20041213.
  5. 1 2 Fekel, Francis C.; Joyce, Richard R.; Hinkle, Kenneth H.; Skrutskie, Michael F. (2000). "Infrared Spectroscopy of Symbiotic Stars. I. Orbits for Well-Known S-Type Systems". The Astronomical Journal. 119 (3): 1375. Bibcode:2000AJ....119.1375F. doi:10.1086/301260.
  6. Stanishev, V.; Zamanov, R.; Tomov, N.; Marziani, P. (2004). "Hα variability of the recurrent nova T Coronae Borealis". Astronomy and Astrophysics. 415 (2): 609. arXiv:astro-ph/0311309. Bibcode:2004A&A...415..609S. doi:10.1051/0004-6361:20034623.
  7. 1 2 3 Iłkiewicz, Krystian; Mikołajewska, Joanna; Stoyanov, Kiril; Manousakis, Antonios; Miszalski, Brent (2016). "Active phases and flickering of a symbiotic recurrent nova T CrB". Monthly Notices of the Royal Astronomical Society. 462 (3): 2695. arXiv:1607.06804. Bibcode:2016MNRAS.462.2695I. doi:10.1093/mnras/stw1837.
  8. 1 2 Wallerstein, George; Harrison, Tanya; Munari, Ulisse; Vanture, Andrew (2008). "The Metallicity and Lithium Abundances of the Recurring Novae T CrB and RS Oph". Publications of the Astronomical Society of the Pacific. 120 (867): 492. Bibcode:2008PASP..120..492W. doi:10.1086/587965.
  9. Pettit, Edison (1946). "The Light-Curves of T Coronae Borealis". Publications of the Astronomical Society of the Pacific. 58: 153. Bibcode:1946PASP...58..153P. doi:10.1086/125797.
  10. Barnard, E. E. (1907). "Nova T Coronae of 1866". Astrophysical Journal. 25: 279. Bibcode:1907ApJ....25..279B. doi:10.1086/141446.
  11. Sanford, Roscoe F. (1949). "High-Dispersion Spectrograms of T Coronae Borealis". Astrophysical Journal. 109: 81. Bibcode:1949ApJ...109...81S. doi:10.1086/145106.
  12. Schaefer, Bradley E. (2009). "Comprehensive Photometric Histories of All Known Galactic Recurrent Novae". The Astrophysical Journal Supplement Series. 187 (2): 275–373. arXiv:0912.4426. Bibcode:2010ApJS..187..275S. doi:10.1088/0067-0049/187/2/275.
  13. "Vmag<2.5". SIMBAD Astronomical Database. Retrieved 2010-06-25.
  14. A Digital Spectral Classification Atlas, R. O. Gray, 34. Unusual Stellar Spectra III: two emission-line stars
  15. "Is T CrB About to Blow its Top?". Sky and Telescope newsletter. Retrieved 2017-08-06.

Further reading

  • Wallerstein, George; Tanya Harrison; Ulisse Munari; Andrew Vanture (11 May 2008). "The Metallicity and Lithium Abundances of the Recurring Novae T CrB and RS Oph". Publications of the Astronomical Society of the Pacific. 120 (867): 492–497. Bibcode:2008PASP..120..492W. doi:10.1086/587965.
  • R and T Coronae Borealis: Two Stellar Opposites at Sky & Telescope
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