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, 2010, and 2022.[6][7]
 | |
| 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[4] ± 0.1334[4] mas[4] |
| Distance | 19600+21000 −5300[2] pc |
| Other designations | |
| Database references | |
| SIMBAD | data |
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 recurring nova. This eruption of U Sco is now the best-observed nova event with 22,000 magnitudes already accumulated. 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.[9]
Originally identified in 1863 by English astronomer N.R. Pogson, U Scorpii was the third recurrent nova to be identified, in the years preceding World War II by Helen L. Thomas.[10][11]
References
edit- ^ 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.
- ^ a b c 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.
- ^ a b "U Scorpii". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-08-17.
- ^ a b c d e 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.
- ^ Comprehensive Photometric Histories of All Known Galactic Recurrent Novae, B. Schaefer
- ^ The 1999 Outburst of the Recurrent Nova U Scorpii, Anupama & Dewangan
- ^ Thar She Blows! U Scorpii Erupts as Predicted, A. MacRobert
- ^ 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.
- ^ Matthew Templeton (May 6, 2010). "Long-term monitoring of the recurrent nova U Scorpii". AAVSO. Retrieved 2010-11-15.
- ^ Templeton, Matthew. "U Scorpii | aavso". www.aavso.org. Retrieved 2022-05-28.
- ^ "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.
External links
edit- http://www.phys.lsu.edu/dept/people/schaefer.html Archived 2009-03-13 at the Wayback Machine
- U Scorpii in Outburst
- Long-term monitoring of the recurrent nova U Scorpii (AAVSO 2010 April 9)
- AAVSO: Quick Look View of AAVSO Observations (get recent magnitude estimates for U Sco)