Q Cygni
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cygnus |
| Right ascension | 21h 41m 43.925s[1] |
| Declination | −35° 21′ 04.9″[1] |
| Apparent magnitude (V) | 3.0 - 15.6[2] |
| Characteristics | |
| Spectral type | K5[3] |
| Variable type | Nova[2] |
| Astrometry | |
| Distance | 741[4] - 3,300[5] pc |
| Absolute magnitude (MV) | +4.85[4] - +1.6[5] |
| Details | |
| White dwarf | |
| Mass | 0.8[4] M☉ |
| Surface gravity (log g) | 8.5[4] cgs |
| Temperature | 31,000[4] K |
| secondary | |
| Mass | 0.6[3] M☉ |
| Other designations | |
| Database references | |
| SIMBAD | data |
Q Cygni (Q Cyg), is a star located in the constellation Cygnus. It is also known as Nova Cygni 1876, and has the designation NGC 7114, and HR 8296. Nova Cygni is located at right ascension 21h 41m 43.925s and declination +42° 50′ 29.07″, in the northwestern portion of Cygnus along the border with Lacerta.
One of the earliest novae recorded,[5] Q Cygni was discovered by astronomer Johann Friedrich Julius Schmidt on November 2, 1876. The star had undergone a nova, brightening to about 3rd magnitude and remaining as bright for four days.[5]
The system is termed a cataclysmic variable,[3] composed of a white dwarf in close orbit with another star that orbit each other every 10 hours. The white dwarf is surrounded by an accretion disc, which blazes much brighter than the star it circles. The system has been estimated to be 740 ± 11 parsecs distant.[4] The secondary star has been estimated to be around 0.6 times as massive as the Sun, making it an orange dwarf of spectral type K5.[3] Also known as a donor star, the secondary supplies mass to the white dwarf via its accretion disc.[3]
A small nebulous disc was reported around the nova and this led to it being listed in the New General Catalogue as a possible planetary nebula. No nebulosity is visible in modern observations and the Revised New General Catalogue lists this as a "non-existent" object.[6]
References
- 1 2 Zacharias, N.; Urban, S. E.; Zacharias, M. I.; Wycoff, G. L.; Hall, D. M.; Germain, M. E.; Holdenried, E. R.; Winter, L. (2003). "VizieR Online Data Catalog: The Second U.S. Naval Observatory CCD Astrograph Catalog (UCAC2)". CDS/ADC Collection of Electronic Catalogues. 1289. Bibcode:2003yCat.1289....0Z.
- 1 2 Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/gcvs. Originally published in: 2009yCat....102025S. 1. Bibcode:2009yCat....102025S.
- 1 2 3 4 5 Peters, Christopher S.; Thorstensen, John R. (2006). "Spectroscopy of Five Old Novae: New or Refined Orbital Periods". The Publications of the Astronomical Society of the Pacific. 118 (843): 687. Bibcode:2006PASP..118..687P. doi:10.1086/504641.
- 1 2 3 4 5 6 Kolobow, Craig; Sion, Edward (2011). "The Amazing Old Nova Q Cygni: A Far-Ultraviolet Synthetic Spectral Analysis". Publications of the Astronomical Society of Pacific. 123 (906): 892–94. Bibcode:2011PASP..123..892K. doi:10.1086/661235.
- 1 2 3 4 Kafka, S.; Tappert, C.; Honeycutt, R. K.; Bianchini, A. (2003). "Spectroscopic Study of Q Cygni: Surprises from an Old Nova". The Astronomical Journal. 126 (3): 1472–82. Bibcode:2003AJ....126.1472K. doi:10.1086/377020.
- ↑ "NGC 7000 - 7840". Retrieved 2016-09-07.