YZ Ceti b

Planet· orbits YZ Ceti

YZ Ceti b - the innermost and lightest of YZ Ceti's three planets (minimum mass ~0.7 Earth), on a 2-day orbit. Never imaged.

Open in 3D viewSee YZ Ceti b in the live, interactive 3D map

Key facts

Minimum mass

4.18 × 10²⁴ kg

0.7 M⊕

Year

2.02 Earth days

Distance from YZ Ceti

2,438,445 km

Minimum mass (m·sin i): 4.18 × 10²⁴ kg · 0.7 M⊕; Radial-velocity detection measures m·sin i; the true mass depends on the unknown orbital inclination.
Radius: Not measured; No transit — radius is a model estimate; true size unknown.

Semi-major axis: 2,438,445 km; From the NASA Exoplanet Archive (radial-velocity orbit)
Eccentricity: 0.06; From the NASA Exoplanet Archive (radial-velocity orbit)
Inclination: 0.00 °; From the NASA Exoplanet Archive (radial-velocity orbit)
Orbital period: 2.0 days; From the NASA Exoplanet Archive (radial-velocity orbit)
Perihelion: 2,292,139 km; Computed from the orbital elements
Aphelion: 2,584,752 km; Computed from the orbital elements
Mean orbital velocity: 87.7 km/s; Computed from the orbital elements

Bulk composition: Presumed rocky (minimum mass ~0.7 Earth); never imaged.
Surface appearance: Appearance based on ESO/M. Kornmesser's artist's concept. No spacecraft has imaged this world, so its real appearance is unknown — The surface shown is an artistic representation, shown only in Visual mode; Realism shows a plain spectral colour.

Insolation: 8.28 S⊕ · 8.28× the sunlight Earth receives; Computed from YZ Ceti's luminosity and the orbital distance (inverse-square; Earth's sunlight = 1).
Equilibrium temperature: 471 K (198 °C); Computed model value — not measured.

Method: Radial-velocity detection (stellar wobble)
Name: Designated 'b' as the first planet found around its star, following the IAU convention of lettering planets in discovery order from 'b'.

One of three low-mass planets found by HARPS in 2017.

No official imagery available — this object has never been visited and no officially-licensed depiction exists.