ROXs 42Bb


ROXs 42Bb is a directly imaged planetary-mass companion to the binary M star ROXs 42B, a likely member of the Rho Ophiuchi cloud complex. The companion was announced/discovered on October 17, 2013 by University of Toronto astronomer Thayne Currie.
The object has an estimated mass around 9 Jupiter masses, depending on the age of the star, similar to the masses of directly imaged planets around HR 8799 and beta Pictoris. However, it is unclear whether ROXs 42Bb formed like these planets via core accretion, formed by disk instability, or formed more like a binary star. Preliminary fits of the spectra and broadband photometry to atmospheric models imply an effective temperature of about 2,000 K for a radius of or about 1,950 K for a radius of. Like Beta Pictoris b, ROXs 42Bb's atmosphere is likely very cloudy and dusty.