Registry · exoplanet

tau Cet g

Exoplanet

harvesting The full record is being pulled from the archives right now — measurement tables, the Gaia row, catalogue photometry. This page will fill itself in.

Right ascension: 01h 44m 02.23s
Declination: −15° 56′ 01.7″
Galactic l, b: 173.07, -73.44
Magnitude V: 3.496
Distance: 3.603 pc

Planet

NASA Exoplanet Archive, composite parameters

Host star	tau Cet · G8.5V
Discovery	Radial Velocity, 2017 · Multiple Observatories
Orbital period	20 d
Semi-major axis	0.133 au
Eccentricity	0.06
Radius	1.18 R⊕ · 0.105 R♃
Mass	1.75 M⊕ · 0.005506 M♃
Density	5.85 g/cm³
Equilibrium temperature	639.65 K
System distance	3.603 pc

Recorded parameters

4 quantities with a single published value

Parameter	Value	Unit	Uncertainty	As published	Source	Reference
Mass	1.75	M_earth	± 0.25	Radial Velocity	NASA Exoplanet Archive	Feng et al. 2017
Orbital period	20	d	± 0.02	Radial Velocity	NASA Exoplanet Archive	Feng et al. 2017
Semi-major axis	0.133	au	± 0.001	Radial Velocity	NASA Exoplanet Archive	Feng et al. 2017
Eccentricity	0.06		± 0.13	Radial Velocity	NASA Exoplanet Archive	Feng et al. 2017

In the same field

within 9 arcmin · wider search

Object	Type	Separation	V
tau Cet f	Exoplanet	0″	3.496
tau Cet	Star	0″	—
tau Cet h	Exoplanet	0″	3.496
* tau Cet c	Planet Candidate	29.8″	—
* tau Cet d	Planet Candidate	29.8″	—
* tau Cet g	Planet	29.8″	—
* tau Cet h	Planet	29.8″	—
* tau Cet f	Planet	29.8″	—
* tau Cet	HighPM*	29.8″	3.5
* tau Cet e	Planet	29.8″	—
* tau Cet b	Planet Candidate	29.8″	—

Provenance

where this card came from

Archive	Read at (UTC)	Record
Seeded from the bulk archive load; no per-object fetch yet.

Machine-readable: /api/v1/object/tau-cet-g · Registry entry updated 2026-08-14.