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 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.
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.
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- 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.
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- 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.
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