Epoch J2000 Equinox J2000
|Right ascension||19h 29m 15.948s|
|Declination||+46° 37′ 19.89″|
|Apparent magnitude (V)||12.27 – 12.46|
|Distance||1843 ly |
|Period (P)||0.45796151 days|
|Semi-major axis (a)||2.992 R☉|
|Periastron epoch (T)||2455688.49913|
|Surface gravity (log g)||4.19 cgs|
|Rotational velocity (v sin i)||149.7 km/s|
|Surface gravity (log g)||4.10 cgs|
|Rotational velocity (v sin i)||84.7 km/s|
KIC 9832227 is a contact binary star system in the constellation Cygnus, located about 1,940 (± ~30) light-years away. It is also identified as an eclipsing binary with an orbital period of almost 11 hours. In 2017, the system was predicted to result in a merger in 2022.2 (± 0.6 years), producing a luminous red nova (LRN) reaching an apparent magnitude of 2. The LRN should remain visible to the naked eye for roughly a month. The merger of the two stellar cores is predicted to give birth to a new, hotter, more massive main-sequence star.
The period of the variations in KIC 9832227 has been observed to be growing shorter since 2013. It is expected that the period will continue to get smaller at an ever-increasing rate, and end in the merging of the two cores. This will release a very large amount of energy, a process which occurred before in the system V1309 Scorpii, a nova which erupted in 2008, and was later found by a team led by Romuald Tylenda to have been the result of a stellar merger. However, astronomers in Tylenda's team have questioned the reliability of the KIC 9832227 prediction, because it is based on a model that may not be accurate enough to predict the eruption time so precisely. The physical mechanism or mechanisms driving such stellar mergers is still not understood, and is the main focus of those researching KIC 9832227.
- Cutri, R. M. (2003). "2MASS All-Sky Catalog of Point Sources". VizieR On-line Data Catalog. 2246. Bibcode:2003yCat.2246....0C.
- "ASAS J192916+4637.3". AAVSO. Retrieved 7 January 2017.
- Molnar, Lawrence A.; Van Noord, Daniel M.; Steenwyk, Steven D.; Spedden, Chris J.; Kinemuchi, Karen (2015). "A prediction of a luminous red nova eruption" (PDF). American Astronomical Society. 225 (225): 415.05. Bibcode:2015AAS...22541505M. Archived from the original (PDF) on 7 January 2017.
- Kinemuchi, Karen (2013-10-01). "To Pulsate or to Eclipse? Status of KIC 9832227 Variable Star". 1310: arXiv:1310.0544. arXiv: . Bibcode:2013arXiv1310.0544K.
- Molnar, Lawrence A.; Van Noord, Daniel; Kinemuchi, Karen; Smolinski, Jason P.; Alexander, Cara E.; Kobulnicky, Henry A.; Cook, Evan M.; Jang, Byoungchan; Steenwyk, Steven D. (2017). "KIC 9832227: A red nova precursor". American Astronomical Society. 229: 417.04. Bibcode:2017AAS...22941704M.
- Carlisle, Camille (6 January 2017). "Paired Stars in Cygnus En Route to Merger". Sky and Telescope. Retrieved 12 January 2017.
- Molnar, Lawrence; et al. "Prediction of a Red Nova Outburst in KIC 9832227" (PDF). Calvin College. Calvin College Group. Archived from the original (PDF) on 7 January 2017. Retrieved 8 January 2017.
- Knapton, Sarah. "Spectacular collision of suns will create new star in night sky in 2022". The Daily Telegraph. Telegraph Media Group. Retrieved 7 January 2017.
- Byrd, Deborah. "Star predicted to explode in 2022". EarthSky. EarthSky Communications. Retrieved 7 January 2017.
- Masi, Gianluca. "Star merging in KIC 9832227: a possible once-in-a-lifetime event". Virtual Telescope Project. Virtual Telescope Project. Retrieved 11 January 2017.
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