HD 95086 b

HD 95086 b

Exoplanet		List of exoplanets
VLT image of the star HD 95086 and its planetary companion, seen here as a blue smudge.
Parent star
Star		HD 95086
Constellation		Carina
Right ascension	(α)	10^h 57^m 03^s
Declination	(δ)	−68° 40′ 02″
Apparent magnitude	(mV)	7.36
Distance		296 ± 11 ly (90.4 ± 3.3 pc)
Spectral type		A8III
Mass	(m)	1.6 M☉
Age		0.017+0.004 −0.004 Gyr
Orbital elements
Semi-major axis	(a)	55 - 61 AU
Physical characteristics
Mass	(m)	5.0 ± 2.0 MJ
Surface gravity	(g)	3.85 ± 0.5 m/s²
Temperature	(T)	1000 ± 100
Discovery information
Discovery date		2013
Discoverer(s)		Rameau et al.
Discovery method		Direct imaging
Discovery site		Very Large Telescope
Discovery status		Confirmed [1]
Other designations
Database references
Extrasolar Planets Encyclopaedia		data
SIMBAD		data
Exoplanet Archive		data
Open Exoplanet Catalogue		data

HD 95086 b is a confirmed,^[1] directly imaged exoplanet orbiting the young, 17 Myr ^[2] A-class pre-main-sequence star HD 95086. It is roughly 5 times as massive as Jupiter and orbits 56–61 AU away from the parent star. It was detected at thermal infrared wavelengths (3.8 µm) through direct imaging, using the NACO instrument on the VLT.^[3] A debris disk has been detected in this system at submillimeter wavelengths and has been resolved in the far-infrared from data obtained with the Herschel Space Observatory.^[4]

The planet was initially detected in data taken in 2012 at a separation from the parent star of 623.9 ± 7.4 mas (~56 AU) and position angle of 151.8 ± 0.8 degrees. The planet was recovered at a high signal-to-noise ratio in June 2013. Astrometry for the planet in January 2012 and June 2013, and from a marginal detection in March 2013 confirm that it is bound to the parent star, not a background star. HD 95086 b's brightness at 3.8 µm when combined with sensitive upper limits on its brightness at shorter wavelengths ^[5] is consistent with trends seen for other young, directly imaged planets like those around HR 8799. In particular, the lower limit of its 1.65–3.8 µm color of 3.1 magnitudes excludes background stars and most brown dwarfs.

The host star is a highly probable member of the Lower Centaurus Crux star forming region.^[6] The star has a mass of 1.6 solar masses making it a late A type star. It is located approximately 90 parsecs away in the constellation of Carina.^[7]

HD-95086b is a massive planet that exists at a large orbital radius, therefore it is a viable candidate for a planet that formed close to its host star and was later scattered outwards via gravitational interactions with other massive particles in orbit around the star. In a debris disk, these particles are of the form of other orbiting planets or planetesimals. This scattering mechanism has been investigated for particles of the form of over-dense fluid elements like those found in a protoplanetary disk containing a planet.^[8] It has been proposed that scattering events could explain observed massive planets at large orbital radii.

Spatially resolved images of the system from the Herschel Space Observatory ^[4] show evidence for a possible 2 belt system with a large clearing between the belts, similar to HR 8799. HD-95086b is probably responsible for carving the sharp inner edge of the outer disk, but additional planets in this system occupying the rest of the gap may be a strong possibility.^[1]

References

1. Rameau, J., Chauvin, G., Lagrange, A.-M., Boccaletti, A., Quanz, S. P., Currie, T., Mawet, D., Girard, J. H., Bonnefoy, M., Kenworthy, M. "Confirmation of the planet around HD 95086 by direct imaging". arXiv:1310.7483.
2. Eric E. Mamajek. "Post-T Tauri Stars in the Nearest OB Association". Retrieved 2002-05-20.
3. Rameau, J. "Discovery of a probable 4-5 Jupiter-mass exoplanet to HD 95086 by direct-imaging". arXiv:1305.7428.
4. Moor, A.; et al. "A resolved debris disk around the candidate planet-hosting star HD95086". arXiv:1309.1675.
5. Meshkat, T.; et al. "Further Evidence of the Planetary Nature of HD 95086 b from Gemini/NICI H-band Data". arXiv:1309.0543.
6. P. T. De Zeeuw (1998-09-14). "A Hipparcos census of the nearby OB associations".
7. F. van Leeuwen. "Validation of the new Hipparcos reduction". Retrieved 2007-08-08.
8. R. Cloutier; M-K. Lin (2013). "Orbital migration of giant planets induced by gravitationally unstable gaps: the effect of planet mass". MNRAS. arXiv:1306.2514. Bibcode:2013MNRAS.434..621C. doi:10.1093/mnras/stt1047.