V1017 Sagittarii
Visual band light curves for the 1973 and 1991 eruptions of V1017 Sagittarii, adapted from Salazar et al. (2017) | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Sagittarius |
| Right ascension | 18h 32m 04.4738s |
| Declination | −29° 23′ 12.5935″ |
| Apparent magnitude (V) | 4.5±2 Max. 13.5 Min. |
| 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 mas/yr Dec.: −10.392±0.066 mas/yr |
| Parallax (π) | 0.7892±0.0437 mas |
| Distance | 1269+84 −60 pc |
| Other designations | |
| Nova Sagittarii 1919, AAVSO 1825-29, Gaia DR2 4048251562703375488, 2MASS J18320447-2923125 | |
| 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.
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. Physical models cannot explain the orbital change of such sign and magnitude as in 2019.