.jpg) An artist's depiction of J0806. | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cancer |
| Right ascension | 08h 06m 22.95196s[1] |
| Declination | +15° 27′ 31.0073″[1] |
| Distance | 1,600 Light-years |
| Binary orbit | |
| Period (P) | 321.5 seconds |
| dP/dt (Pdot) | 1.1 milliseconds per year |
| Separation: | 0.0005 AU |
| Details | |
| Mass | 0.5 (primary) / 0.5 (b) M☉ |
| Other designations | |
RX J0806.3+1527, RX J0806, J0806, HM Cancri, HM Cnc | |
| Database references | |
| SIMBAD | data |
HM Cancri (also known as HM Cnc or RX J0806.3+1527) is a binary star system about 1,600 light-years (490 pc; 1.5×1016 km) away.[2] It comprises two dense white dwarfs orbiting each other once every 5.4 minutes, at an estimated distance of only 80,000 kilometres (50,000 mi) apart (about 1/5 the distance between the Earth and the Moon). The two stars orbit each other at speeds in excess of 400 kilometres per second (890,000 mph). The stars are estimated to be about half as massive as the Sun. Like typical white dwarfs, they are extremely dense, being composed of degenerate matter, and so have radii on the order of the Earth's radius. Astronomers believe that the two stars will eventually merge, based on data from many X-ray satellites, such as Chandra X-Ray Observatory, XMM-Newton and the Swift Gamma-Ray Burst Mission. These data show that the orbital period of the two stars is steadily decreasing at a rate of 1.2 milliseconds per year as they thus are getting closer by approximately 60 centimetres (2.0 ft) per day. At this rate, they can be expected to merge in approximately 340,000 years. With a revolution period of 5.4 minutes, HM Cancri is the shortest orbital period binary white dwarf system currently known.
- ^ a b 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.
- ^ "RX J0806.3+1527: Orbiting Stars Flooding Space with Gravitational Waves". CHANDRA X-RAY OBSERVATORY, Harvard. 2005-05-30. Archived from the original on 2011-02-25. Retrieved 2013-05-31.
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