Extrasolar Visions - gamma Cephei A b

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Sulfurous Cloud Jovian

Object Type:

Sulfurous Cloud Jovian

Parent Star:

gamma Cephei A (K1 IV)

Discovery Status:

Confirmed

Habitability:

Planet at inner edge of Habitable Zone at Mean Orbital Distance

Current Planet

Habitability Zone

Mass :

1.59 Jupiters

Periastron Distance:

1.62 AU

Mean Distance:

2.029 AU

Apastron Distance:

2.43 AU

Orbital Period:

902.26 ± 6 Days

Eccentricity:

0.2 ± 0.069

Argument of Perihelion (omega):

75.6 °

Radial Velocity of Star:

26.3 m/s

System Age:

3000 Myr

Planet Appearance:

Sulfur stained clouds of water or H₂SO₄

Estimated Radius:

1.03 Jupiters ¹

Estimated Periastron Temp:

360 Kelvin

Estimated Mean Temp:

322 Kelvin

Estimated Apastron Temp:

294 Kelvin

Temp from
Internal Heating :

137.563 Kelvins ²

Max Angular Star Size:

1.543°

Mean Angular Star Size:

1.232°

Min Angular Star Size:

1.028°

Gravitational Influence
(Hill Sphere):

0.138 AU / 20720000 km

Max Stable Prograde Moon Orbit:

0.049 AU / 7450000 km

Max Moon Mass:

> 10 Earths ³

Tidally locked if older than:

> 20 Gyr ⁴

Estimated Bond Albedo:

~ 0.7 ⁵

Notes:
    ¹ from planet formation models of Burrows et al
    ² from planet formation models of Burrows et al
    ³ based on periastron due to high eccentricity
    ⁴ orbit may be too eccentric for 1:1 tidal lock
    ⁵ from Sudarsky et al. 2000

Year Discovered:

Sep 2002

Detection Method:

Doppler Spectroscopy

Discovered By:

COCHRAN W., HATZES A., ENDL M., PAULSON D., WALKER G., CAMPBELL B. & YANG S.

Click image below to enlarge

gamma Cephei b is the first planet discovered in a close binary star system. At their closest, the two stars are only 12 AU from each other, proving that such close systems can support planets. This discovery also ups the likely number of planets in the galaxy as most stars are in double or triple star systems.

View a VRML model of the system. Please be patient while the file downloads.

For a VRML tour of our galaxy's exoplanets, check out Extrasolar VR.

	gamma Cephei Ab Photochemically generated sulfurous compounds stain the water clouds of gamma Cephei Ab yellow. In the foreground, a dense rocky moon with the mass of Mercury bears the scars of tectonic fractures and basaltic lava plains caused by the intense gravitational tides of its parent jovian.
	In the Shadow of g Cep Ab The night side of gamma Cephei Ab flickers with titanic lightning storms. Only a thin sliver of the planet and its moon remain in sunlight from this vantage point. In the distance, the planet's two stars glow. The nearby K1 subgiant shines brightly, but the light of the M1 red dwarf, 13 AU away, is feeble and distant.

View the Night Sky from gamma Cephei A b...
	Cylindrical All Sky View (750 x 1500 pixels)
	Northern Hemisphere (750 x 750 pixels)
	Southern Hemisphere (750 x 750 pixels)