V1017 Sagittarii

V1017 Sagittarii

Visual band light curves for the 1973 and 1991 eruptions of V1017 Sagittarii, adapted from Salazar et al. (2017)[1]
Observation data Epoch J2000      Equinox J2000
Constellation	Sagittarius
Right ascension	18^h 32^m 04.4738^s[2]
Declination	−29° 23′ 12.5935″[2]
Apparent magnitude (V)	4.5±2 Max. 13.5 Min.[3]
Characteristics
Spectral type	G5IIIp / white dwarf
Variable type	eclipsing recurrent nova (NR+E)
Astrometry
Radial velocity (Rv)	15 km/s
Proper motion (μ)	RA: 5.241±0.086[2] mas/yr Dec.: −10.392±0.066[2] mas/yr
Parallax (π)	0.7892 ± 0.0437 mas[2]
Distance	1269+84 −60[3] pc
Other designations
Nova Sagittarii 1919, AAVSO 1825-29, Gaia DR2 4048251562703375488, 2MASS J18320447-2923125[4]
Database references
SIMBAD	data

V1017 Sagittarii is a cataclysmic variable star system in the constellation Sagittarius. It first erupted in 1919, reaching magnitude 7. Its other eruptions in 1901, 1973 and 1991 only reached magnitude 10, leading it to be reclassified from a recurrent nova to a dwarf nova.[5]

After the eruption of 1919, the orbital period of the binary system has decreased by 0.0273±0.0061%, to the 5.786290±0.000032 days.[1] Physical models cannot explain the orbital change of such sign and magnitude as in 2019.[6]

References

1. Salazar, Irene V.; Lebleu, Amy; Schaefer, Bradley E.; Landolt, Arlo U.; Dvorak, Shawn (2017). "Accurate pre- and post-eruption orbital periods for the dwarf/Classical nova V1017 SGR". Monthly Notices of the Royal Astronomical Society. 469 (4): 4116–4132. arXiv:1612.00405. doi:10.1093/mnras/stx1161.
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.
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.
4. "V1017 Sagittarii". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-08-25.
5. Schaefer, Bradley E. (2010). "Comprehensive Photometric Histories of All Known Galactic Recurrent Novae". The Astrophysical Journal Supplement. 187 (2): 275–373. arXiv:0912.4426. Bibcode:2010ApJS..187..275S. doi:10.1088/0067-0049/187/2/275. S2CID 119294221.
6. Schaefer, Bradley E. (2020). "Sudden and steady orbital period changes across six classical Nova Eruptions: The end of hibernation and two serious challenges for the magnetic braking model of cataclysmic variable evolution". Monthly Notices of the Royal Astronomical Society. 492 (3): 3343–3358. arXiv:1912.06170. doi:10.1093/mnras/stz3424.