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Home -> Astronomy News -> Stars -> SDSS J065133.33 +284423.3
Post Info TOPIC: SDSS J065133.33 +284423.3
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RE: SDSS J065133.33 +284423.3
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Evolved Stars Locked in Fatalistic Dance

White dwarfs are the burned-out cores of stars like our Sun. Astronomers have discovered a pair of white dwarfs spiralling into one another at breakneck speeds. Today, these white dwarfs are so near they make a complete orbit in just 13 minutes, but they are gradually slipping closer together. About 900,000 years from now - a blink of an eye in astronomical time - they will merge and possibly explode as a supernova. By watching the stars converge, scientists will test both Einstein's general theory of relativity and the origin of some peculiar supernovae.
The two white dwarfs are circling at a bracing speed of 370 miles per second (600 km/s), or 180 times faster than the fastest jet on Earth.
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Title: A 12 minute Orbital Period Detached White Dwarf Eclipsing Binary
Authors: Warren R. Brown (1), Mukremin Kilic (1), J. J. Hermes (2), Carlos Allende Prieto (3), Scott J. Kenyon (1), D. E. Winget (2) ((1) SAO, (2) UT Austin, (3) IAC)

We have discovered a detached pair of white dwarfs (WDs) with a 12.75 min orbital period and a 1,315 km/s radial velocity amplitude. We measure the full orbital parameters of the system using its light curve, which shows ellipsoidal variations, Doppler boosting, and primary and secondary eclipses. The primary is a 0.25 Msun tidally distorted helium WD, only the second tidally distorted WD known. The unseen secondary is a 0.55 Msun carbon-oxygen WD. The two WDs will come into contact in 0.9 Myr due to loss of energy and angular momentum via gravitational wave radiation. Upon contact the systems may merge yielding a rapidly spinning massive WD, form a stable interacting binary, or possibly explode as an underluminous supernova type Ia. The system currently has a gravitational wave strain of 10^-22, about 10,000 times larger than the Hulse-Taylor pulsar; this system would be detected by the proposed LISA gravitational wave mission in the first week of operation. This system's rapid change in orbital period will provide a fundamental test of general relativity.

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