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 would remain visible to the naked eye for roughly a month. The merger of the two stellar cores was predicted to give birth to a new, hotter, more massive main-sequence star. However, a reanalysis of the data in September 2018 revealed that the prediction had been based on a wrongly-timed observation, negating the predicted merger.
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|
The period of the variations in KIC 9832227 has been observed to be growing shorter since 2013, leading to the prediction of the merger in 2022. In September 2018, it was announced that the original prediction was based on a timing offset of 12 hours in one of the datasets. This shows that the period had actually been increasing up to about 2008. The cause for the period variation is still unknown, but it is unlikely that the system will end in a merger at the predicted time.
- 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". arXiv:1310.0544 [astro-ph.SR].
- 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.
- Molnar, Lawrence A. (7 September 2018). "Supplementary material to Calvin College press release "Team of researchers challenge bold astronomical prediction", September 7, 2018". calvin.edu. Retrieved 8 September 2018.
- Kucinski, Matt (7 September 2018). "Team of researchers challenge bold astronomical prediction". calvin.edu. Retrieved 8 September 2018.
- Parks, Jake (7 September 2018). "Two stars will NOT merge and explode into red fury in 2022". astronomy.com.
- Carlisle, Camille (6 January 2017). "Paired Stars in Cygnus En Route to Merger". Sky and Telescope. Retrieved 12 January 2017.
- Socia, Quentin J.; Welsh, William F.; Short, Donald R.; Orosz, Jerome A.; Angione, Ronald J.; Windmiller, Gur; Caldwell, Douglas A.; Batalha, Natalie M. (11 September 2018). "KIC 9832227: Using Vulcan Data to Negate the 2022 Red Nova Merger Prediction". Astrophysical Journal Letters. 864 (2): L32. arXiv:1809.02771. Bibcode:2018ApJ...864L..32S. doi:10.3847/2041-8213/aadc0d. S2CID 56134618.
- Molnar, Lawrence; et al. (4 January 2017). "Prediction of a Red Nova Outburst in KIC 9832227" (PDF). Calvin College (draft ed.). 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.
|This binary or multiple star system–related article is a stub. You can help Wikipedia by expanding it.|
|This variable star–related article is a stub. You can help Wikipedia by expanding it.|