Oph 162225-240515

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**Oph 162225-240515**
Observation Data Epoch J2000
IAU Constellation	Ophiuchus
Right Ascension	16:22:25
Declination	-24 05 15
Distance	400 ly (140 pc)

Oph 162225-240515 or just Oph1622 is a pair of brown dwarfs that have been reported as orbiting each other, and not any star. The bodies are located in Ophiuchus, and are about 400 light years away. The larger of the two, Oph1622A, is officially a brown dwarf of about 17.5 Jupiter masses. The smaller, Oph1622B, has about 15.5 Jupiter masses and is located 1.94 arcseconds away, at a position angle of 182°. They are estimated to be around 5 million years old.

Announced in the August 4, 2006 issue of Science by Ray Jayawardhana and Valentin D. Ivanov, the objects were discovered using telescopes of the European Southern Observatory's "New Technology Telescope" in La Silla, Chile. The masses were originally reported to be lower, at 14 and 7 Jupiter masses, which would have made the smaller object a planetary-mass object, or "planemo". The system was announced as the first reported binary system of objects this small. However later observations revised the masses upward, and both are above the 13 Jupiter mass dividing line between planets and brown dwarfs.

The distance between the two is approximately 240 Astronomical Units - a distance so great that Space.com wrote that "their connection is so tenuous ... that a passing star or brown dwarf could permanently separate the two objects." As such, the discovery was reported as casting doubt on the theory that such free-floating planet-like objects have been ejected from a stellar system, such an event being too violent to leave them in orbit around each other.

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[edit] References

Ray Jayawardhana and Valentin D. Ivanov: Discovery of a Young Planetary Mass Binary. In Science, August 4, 2006 (abstract)
Laird Close et al. New Masses and Ages for the Planetary Mass Binary Candidate Ophiuchus #11 (2MASS J16222521-2405139) and the Discovery of Another Very Wide, Low-Mass, Binary in Ophiuchus (2MASS J16233609-2402209). Submitted to the Astrophysical Journal (arxiv preprint)