V1057 Cygni

Summary

V1057 Cygni is a suspected binary star[8] 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,[3] in the North America Nebula.[4] It has an apparent visual magnitude of around 12.4.[4]

V1057 Cygni

A visual band light curve for V1057 Cygni. The main plot shows the long-term variability, and the inset shows the short-term variability. Adapted from Kopatskaya et al. (2002)[1] and Clarke et al. (2005).[2]
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Cygnus
Right ascension 20h 58m 53.73367s[3]
Declination +44° 15′ 28.3847″[3]
Apparent magnitude (V) 12.43±0.03[4]
Characteristics
Spectral type F7/G3 I/IIe[5]
B−V color index 1.93[6]
Variable type FU Ori
Astrometry
Proper motion (μ) RA: −2.793[3] mas/yr
Dec.: −3.813[3] mas/yr
Parallax (π)1.0864 ± 0.0388 mas[3]
Distance3,000 ± 100 ly
(920 ± 30 pc)
Details
Radius16.2+1.2
−3.2
[3] R
Luminosity38.3±2.0[3] L
Temperature3,565+414
−127
[3] K
Other designations
V1057 Cyg, LkHα 190, AAVSO 2055+43[7]
Database references
SIMBADdata

The initial classification of the primary was as a young T Tauri star.[4] 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.[8] The mass of FU Ori objects is estimated to be in the range of 0.3–0.7 M.[4]

A faint binary companion was discovered in 2016, and designated component B. It is located at a projected separation of 30±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.[4]

References edit

  1. ^ Kopatskaya, E. N.; Grinin, V. P.; Shakhovskoi, D. N.; Shulov, O. S. (April 2002). "Results of Photometric and Polarimetric Observations of the Fuor V1057 Cyg from the Time of an Outburst to the Present". Astrophysics. 45 (2): 143–149. Bibcode:2002Ap.....45..143K. doi:10.1023/A:1016052529802. S2CID 117012043. Retrieved 21 December 2021.
  2. ^ Clarke, C.; Lodato, G.; Melnikov, S. Y.; Ibrahimov, M. A. (August 2005). "The photometric evolution of FU Orionis objects: disc instability and wind–envelope interaction". Monthly Notices of the Royal Astronomical Society. 361 (3): 942–954. arXiv:astro-ph/0505515. Bibcode:2005MNRAS.361..942C. doi:10.1111/j.1365-2966.2005.09231.x.
  3. ^ a b c d e f g h i 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.
  4. ^ a b c d e f 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. S2CID 118652194. 29.
  5. ^ 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.
  6. ^ Zacharias, N. (2012). "The fourth US Naval Observatory CCD Astrograph Catalog (UCAC4)". VizieR On-line Data Catalog. 1322 (2): 44. arXiv:1212.6182. Bibcode:2012yCat.1322....0Z. doi:10.1088/0004-6256/145/2/44. S2CID 119299381.
  7. ^ "LkHA 190". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2020-11-16.
  8. ^ a b 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.