HAT-P-9 b

HAT-P-9 b Image

Description: HAT-P-9b, formally named Alef, is an exoplanet approximately 1500 light years away in the constellation Auriga. This planet was found by the transit method on June 26, 2008. It has a mass 78% that of Jupiter and a radius 140% that of Jupiter. As with most transiting planets, this planet is a hot Jupiter, meaning this Jupiter-like planet orbits extremely close to its parent star, taking only 3.92 days to orbit.

Physical Properties

Mass (Jupiter mass): 0.749 MJ

Radius (Jupiter radius): 1.393 RJ

Density: 0.342 g/cm³

Equilibrium Temperature: 1540.0 K

Orbital Parameters

Orbital Period: 3.92281072 days

Semi-major Axis: 0.05287 AU

Eccentricity: 0.084

Inclination: 86.44°

Host Star Properties

Host Star: HAT-P-9

Spectral Type: F7

Temperature: 6350.0 K

Stellar Mass: 1.28 M☉

Stellar Radius: 1.34 R☉

Discovery Information

Planet Letter: b

Object ID: 3.11028

Host ID: 2.103442

Discovery Date: 2009-01

Discovery Year: 2008

Discovery Method: Transit

Discovery Locale: Ground

Discovery Facility: HATNet

Discovery Instrument: 2K CCD Sensor

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