Mini-Neptune · HD 180617

HD 180617 b

ExoplanetsDiscovered 2018

Scientific overview

HD 180617 b is a mini-neptune orbiting HD 180617, completing an orbit every 106 days, about 19 light-years from Earth. It was discovered in 2018 using the radial velocity method.

Host star

HD 180617

Spectral type

M2.5 V

Temperature

3,534 K

Mass

0.484 M☉

Discovery and detection

Detection method

Radial Velocity Method

Discovery year

2018

Knowledge connections

OrbitsHD 180617
Discovered by methodRadial Velocity Method
Catalogued inNASA Exoplanet Archive

Quick facts

Class: Mini-Neptune
Host star: HD 180617
Discovery method: Radial Velocity Method
Discovery year: 2018
Orbital period: 105.911 d
Semi-major axis: 0.343 AU
Eccentricity: 0.101
Radius: 3.53 R⊕
Mass: 12.21 M⊕
Density: 1.53 g/cm³ · derived
Equilibrium temp.: 202 K
Insolation: 0.28 S⊕
Distance: 19 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 density1.53 g/cm³derived
Formula & inputs
Formula: ρ = M / (4⁄3·π·r³) (v1.0.0, impl v1.0.0)
Inputs:
- massEarth = 12.21 M⊕ · NASA
- radiusEarth = 3.53 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.