ROXs 42Bb is a directly imaged

planet A planet is a large, Hydrostatic equilibrium, rounded Astronomical object, astronomical body that is generally required to be in orbit around a star, stellar remnant, or brown dwarf, and is not one itself. The Solar System has eight planets b ...

ary-mass companion to the binary M star ROXs 42B, a likely member of the

Rho Ophiuchi cloud complex The Rho Ophiuchi cloud complex is a complex of interstellar clouds with different nebulae, particularly a dark nebula which is centered 1° south of the star ρ Ophiuchi, which it among others extends to, of the constellation Ophiuchus. At an est ...

. The companion was announced/discovered on October 17, 2013, by

University of Toronto The University of Toronto (UToronto or U of T) is a public university, public research university whose main campus is located on the grounds that surround Queen's Park (Toronto), Queen's Park in Toronto, Ontario, Canada. It was founded by ...

astronomer

Thayne Currie Thayne is a town in Lincoln County, Wyoming, United States. The population was 380 at the 2020 census. Geography Thayne is located at (42.919754, –111.000714), at 5906 feet in elevation. It sits in the northern portion of Wyoming's grass ...

. 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 HR 8799 is a roughly 30 million-year-old main sequence, main-sequence star located away from Earth in the constellation of Pegasus (constellation), Pegasus. It has roughly 1.5 times the Sun's mass and 4.9 times its lumino ...

and

beta Pictoris Beta Pictoris (abbreviated β Pictoris or β Pic) is the second brightest star in the constellation Pictor. It is located from the Solar System, and is 1.75 times as massive and 8.7 times as luminous as the Sun. The Beta Pictoris s ...

. However, it is unclear whether ROXs 42Bb formed like these planets via core accretion, by disk (gravitational) instability, or more like a

binary star A binary star or binary star system is a system of two stars that are gravitationally bound to and in orbit around each other. Binary stars in the night sky that are seen as a single object to the naked eye are often resolved as separate stars us ...

. Preliminary fits of the spectra and broadband photometry to atmospheric models imply a radius of for an effective temperature of about 2,000 K or a radius of for about 1950 K. Like

Beta Pictoris b Beta Pictoris b (abbreviated as β Pic b) is an exoplanet orbiting the young debris disk A-type main sequence star Beta Pictoris located approximately 63 light-years (19.4 parsecs, or km) away from Earth in the constellation of Pictor. It has a ...

, ROXs 42Bb's atmosphere is likely very cloudy and dusty. The object is located in the constellation

Ophiuchus Ophiuchus () is a large constellation straddling the celestial equator. Its name comes from the Ancient Greek (), meaning "serpent-bearer", and it is commonly represented as a man grasping a snake. The serpent is represented by the constellati ...

, near the border with

Scorpius Scorpius is a zodiac constellation located in the Southern celestial hemisphere, where it sits near the center of the Milky Way, between Libra to the west and Sagittarius to the east. Scorpius is an ancient constellation whose recognition pred ...

References

Exoplanets discovered in 2013 Exoplanets detected by direct imaging Circumbinary planets Ophiuchus {{Extrasolar-planet-stub

See also

References