Gas giant · HD 18438

HD 18438 b

ExoplanetsDiscovered 2023

Scientific overview

HD 18438 b is a gas giant orbiting HD 18438, completing an orbit every 803 days, about 731 light-years from Earth. It was discovered in 2023 using the radial velocity method.

Host star

HR 881

Spectral type

M2.5 III

Temperature

3,860 K

Mass

1.84 M☉

Discovery and detection

Detection method

Radial Velocity Method

Discovery year

2023

Knowledge connections

OrbitsHR 881
Discovered by methodRadial Velocity Method
Catalogued inNASA Exoplanet Archive

Quick facts

Class: Gas giant
Host star: HR 881
Discovery method: Radial Velocity Method
Discovery year: 2023
Orbital period: 803 d
Semi-major axis: 2.1 AU
Eccentricity: 0.1
Radius: 12.1 R⊕
Mass: 6674.4 M⊕
Density: 20.77 g/cm³ · derived
Equilibrium temp.: 1208 K
Insolation: 210.66 S⊕
Distance: 731 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 density20.77 g/cm³derived
Formula & inputs
Formula: ρ = M / (4⁄3·π·r³) (v1.0.0, impl v1.0.0)
Inputs:
- massEarth = 6674.4 M⊕ · NASA
- radiusEarth = 12.1 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.