Gas giant · HD 17156

HD 17156 b

ExoplanetsDiscovered 2007

Scientific overview

HD 17156 b is a gas giant orbiting HD 17156, completing an orbit every 21 days, about 255 light-years from Earth. It was discovered in 2007 using the radial velocity method.

Host star

Nushagak

Spectral type

Temperature

6,046 K

Mass

1.285 M☉

Discovery and detection

Detection method

Radial Velocity Method

Discovery year

2007

Discovered at

Subaru Telescope

Knowledge connections

OrbitsNushagak
Discovered by methodRadial Velocity Method
Discovered atSubaru Telescope
Catalogued inNASA Exoplanet Archive

Quick facts

Class: Gas giant
Host star: Nushagak
Discovery method: Radial Velocity Method
Discovery year: 2007
Orbital period: 21.2164 d
Semi-major axis: 0.1632 AU
Eccentricity: 0.677
Radius: 12.26 R⊕
Mass: 1036.12 M⊕
Density: 3.10 g/cm³ · derived
Equilibrium temp.: 888 K
Insolation: 68.8 S⊕
Distance: 255 ly

Density is derived from the archive mass and radius via ρ = M / (4⁄3·π·r³); all other values are catalogued measurements.

Derived values

Computed from source-backed inputs via standard formulae — not observations. Every input and constant is traced below.

Bulk density3.10 g/cm³derived
Formula & inputs
Formula: ρ = M / (4⁄3·π·r³) (v1.0.0, impl v1.0.0)
Inputs:
- massEarth = 1036.12 M⊕ · NASA
- radiusEarth = 12.26 R⊕ · NASA
Assumptions: M⊕ = 5.972e+24 kg, R⊕ = 6371000 m (IAU 2015 B3 nominal); Assumes a uniform sphere.
Limitations: Withheld above 30 g/cm³ (inconsistent mass/radius inputs).; Archive mass/radius carry no propagated uncertainty here.
Uncertainty: not propagated (inputs carry no catalogued uncertainty)
Computed as of 2026-06-29.

Quality & authority

Partial

Unreviewed

Description: Complete
Source coverage: Partial
Relationship coverage: Complete
Review coverage: None
Citation coverage: None
Image coverage: Not applicable

Data from the NASA Exoplanet Archive. See source quality.