U Scorpii

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U Scorpii
UScoLocation.png
Location of U Scorpii (circled in red)
Observation data
Epoch J2000       Equinox J2000
Constellation Scorpius
Right ascension 16h 22m 30.78s [1]
Declination −17° 52 42.8 [1]
Apparent magnitude  (V)7.5 Max.
17.6 Min. [2]
Characteristics
Spectral type ? / White Dwarf
Variable type Recurrent nova [2]
Astrometry
Radial velocity (Rv)65 [3] km/s
Proper motion (μ)RA: −0.380±0.202 [4] mas/yr
Dec.: −7.591±0.144 [4] mas/yr
Parallax (π)−0.0945±0.1334  mas [4]
Distance 19600+21000
−5300
[2]   pc
Other designations
AAVSO 1616-17, Nova Sco 1863, BD−17 4554, Gaia DR2 6246188565119443072, 2MASS J16223079-1752431 [3]
Database references
SIMBAD data

U Scorpii (U Sco) is a recurrent nova system, one of 10 known recurring novae in the Milky Way galaxy. [5] Located near the northern edge of the constellation Scorpius it normally has a magnitude of 18, but reaches a magnitude of about 8 during outbursts. Outbursts have been observed in 1863, 1906, 1936, 1979, 1987, 1999, [6] 2010, [7] and 2022.

The 2010 outburst was predicted to occur April 2009 ± 1.0 year, based on observations during quiescence following the 1999 outburst. [8] The U Sco 2010 eruption faded by 1 magnitude in 1 day, and by 4 magnitudes in 6 days. By February 6 it was dimmer than magnitude 13. Between February 10–19, it was flickering around magnitude 14. The eruption ended on day 64, which is the fastest observed decline to quiescence of a recurring nova. [9] This eruption of U Sco became the best-observed nova event to its day, with 22,000 magnitudes accumulated. [9] Astronomers then predicted that another eruption of U Sco would occur in 2020±2. This prediction was correct: it brightened to +7.8 magnitude on 6 June 2022.[ citation needed ]

AAVSO light curve of recurrent nova U Sco from 1 Jan 2010 to 1 Sept 2010. Up is brighter and down is fainter. Day numbers are Julian day. Different colors reflect different bandpasses. U-Sco-2010-Lightcurve-AAVSO.png
AAVSO light curve of recurrent nova U Sco from 1 Jan 2010 to 1 Sept 2010. Up is brighter and down is fainter. Day numbers are Julian day. Different colors reflect different bandpasses.

Originally identified as a nova in 1863 by English astronomer N.R. Pogson, U Scorpii was the third nova to be identified as recurrent, by American astronomer and historian of science Helen L. Thomas, in the years preceding World War II. [10] [11]

References

  1. 1 2 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. 1 2 3 Schaefer, Bradley E. (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 . S2CID   118925493.
  3. 1 2 "U Scorpii". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 2019-08-17.
  4. 1 2 3 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 at VizieR.
  5. Comprehensive Photometric Histories of All Known Galactic Recurrent Novae, B. Schaefer
  6. The 1999 Outburst of the Recurrent Nova U Scorpii, Anupama & Dewangan
  7. Thar She Blows! U Scorpii Erupts as Predicted, A. MacRobert
  8. B. Schaefer; A. Pagnotta; et al. (October 2010). "Discovery of the 2010 Eruption and the Pre-Eruption Light Curve for Recurrent Nova U Scorpii". The Astronomical Journal. 140 (4): 925–932. arXiv: 1004.2842 . Bibcode:2010AJ....140..925S. doi:10.1088/0004-6256/140/4/925. S2CID   118394042 . Retrieved 12 February 2015.
  9. 1 2 Matthew Templeton (May 6, 2010). "Long-term monitoring of the recurrent nova U Scorpii". AAVSO. Retrieved 2010-11-15.
  10. Templeton, Matthew. "U Scorpii | aavso". www.aavso.org. Retrieved 2022-05-28.
  11. "Eloge: Helen Meriwether Lewis Thomas, 21 August 1905-6 August 1997" . Isis. 89 (2): 316–317. 1998-06-01. doi:10.1086/384004. ISSN   0021-1753. S2CID   144636725.