V1057 Cygni
V1057 Cygni is a suspected binary star[6] system in the northern constellation of Cygnus. It is a variable star of the FU Orionis-type, and was the second FU Orionis-type variable to be discovered. The system is located at a distance of approximately 3,000 light years from the Sun,[1] in the North America Nebula.[2] It has an apparent visual magnitude of around 12.4.[2]
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Cygnus |
| Right ascension | 20h 58m 53.73367s[1] |
| Declination | +44° 15′ 28.3847″[1] |
| Apparent magnitude (V) | 12.43±0.03[2] |
| Characteristics | |
| Spectral type | F7/G3 I/IIe[3] |
| B−V color index | 1.93[4] |
| Variable type | FU Ori |
| Astrometry | |
| Proper motion (μ) | RA: −2.793[1] mas/yr Dec.: −3.813[1] mas/yr |
| Parallax (π) | 1.0864 ± 0.0388[1] mas |
| Distance | 3,000 ± 100 ly (920 ± 30 pc) |
| Details | |
| Radius | 16.2+1.2 −3.2[1] R☉ |
| Luminosity | 38.3±2.0[1] L☉ |
| Temperature | 3,565+414 −127[1] K |
| Other designations | |
| Database references | |
| SIMBAD | data |
The initial classification of the primary was as a young T Tauri star.[2] During 1969–1970 it underwent a nova-like outburst, increasing in brightness by five magnitudes and emitting a strong mass outflow. For the next ten years the brightness stayed at a plateau before decreasing rapidly in the mid–1990s, accompanied by a change in its spectrum. As of 2013, it is 1.5 magnitudes brighter than it was before the nova-like event.[6] The mass of FU Ori objects is estimated to be in the range of 0.3–0.7 M☉.[2]
A faint binary companion was discovered in 2016, and designated component B. It is located at a projected separation of 30±5 AU from the primary, with a possible orbital period of ~300 years. The 1970 outburst of the primary may have been caused by torque of its accretion disk by the companion.[2]
References
- 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.
- Green, Joel D.; et al. (October 2016). "Testing the Binary Trigger Hypothesis in FUors". The Astrophysical Journal. 830 (1): 5. arXiv:1605.03270. Bibcode:2016ApJ...830...29G. doi:10.3847/0004-637X/830/1/29. 29.
- Herbig, G. H.; et al. (2003). "High-Resolution Spectroscopy of FU Orionis Stars". The Astrophysical Journal. 595 (1): 384–411. arXiv:astro-ph/0306559. Bibcode:2003ApJ...595..384H. doi:10.1086/377194. S2CID 119436366.
- Zacharias, N. (2012). "The fourth US Naval Observatory CCD Astrograph Catalog (UCAC4)". VizieR On-line Data Catalog. 1322. arXiv:1212.6182. Bibcode:2012yCat.1322....0Z.
- "LkHA 190". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2020-11-16.
- Kopatskaya, E. N.; et al. (September 2013). "Photometric behaviour of the FU Orionis type star, V1057 Cygni, during the last 25 years". Monthly Notices of the Royal Astronomical Society. 434 (1): 38–45. Bibcode:2013MNRAS.434...38K. doi:10.1093/mnras/stt963.