Registry · exoplanet

HD 217107 c

Exoplanet 70 papers

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: 22h 58m 15.53s
Declination: −02° 23′ 43.6″
Galactic l, b: 70.474, -53.32
Magnitude V: 6.155
Distance: 20.062 pc

Also known as

1 identifiers

HD 217107c

Planet

NASA Exoplanet Archive, composite parameters

Host star	HD 217107 · G8IV-V
Discovery	Radial Velocity, 2005 · Lick Observatory
Orbital period	5,138.7 d
Semi-major axis	5.922 au
Eccentricity	0.3918
Radius	12.9 R⊕ · 1.15 R♃
Mass	1,388.9 M⊕ · 4.37 M♃
Density	3.56 g/cm³
Equilibrium temperature	123.27 K
System distance	20.062 pc

Published measurements

4 quantities measured more than once

One object can carry a dozen published estimates of the same quantity. The register keeps them side by side rather than picking a winner — the citation is part of the value.

Mass 8 values

Value	Unit	Uncertainty	Band / method	Source	Reference	Year
1,430.228	M_earth	± 38.14	Radial Velocity	NASA Exoplanet Archive	An et al. 2025	2025
1,388.91	M_earth	± 41.32	Radial Velocity	NASA Exoplanet Archive	Giovinazzi et al. 2025	2025
1,369.84	M_earth	± 41.32	Radial Velocity	NASA Exoplanet Archive	Rosenthal et al. 2021	2021
1,423.878	M_earth	± 63.57	Radial Velocity	NASA Exoplanet Archive	Bryan et al. 2016	2016
1,434.306	M_earth	± 22.88	Radial Velocity	NASA Exoplanet Archive	Feng et al. 2015	2015
826.32	M_earth	± 47.67	Radial Velocity	NASA Exoplanet Archive	Wright et al. 2009	2009
794.54	M_earth	± 152.6	Radial Velocity	NASA Exoplanet Archive	Wittenmyer et al. 2007	2007
667.4	M_earth	± 318	Radial Velocity	NASA Exoplanet Archive	Vogt et al. 2005	2005

Orbital period 8 values

Value	Unit	Uncertainty	Band / method	Source	Reference	Year
5,164.6	d	± 15	Radial Velocity	NASA Exoplanet Archive	An et al. 2025	2025
5,138.7	d	± 11	Radial Velocity	NASA Exoplanet Archive	Giovinazzi et al. 2025	2025
5,141	d	± 13	Radial Velocity	NASA Exoplanet Archive	Rosenthal et al. 2021	2021
5,178	d	± 74	Radial Velocity	NASA Exoplanet Archive	Bryan et al. 2016	2016
5,189	d	± 21	Radial Velocity	NASA Exoplanet Archive	Feng et al. 2015	2015
4,270	d	± 220	Radial Velocity	NASA Exoplanet Archive	Wright et al. 2009	2009
3,352	d	± 157	Radial Velocity	NASA Exoplanet Archive	Wittenmyer et al. 2007	2007
3,150	d	± 1,000	Radial Velocity	NASA Exoplanet Archive	Vogt et al. 2005	2005

Semi-major axis 7 values

Value	Unit	Uncertainty	Band / method	Source	Reference	Year
6.1	au	± 0.06	Radial Velocity	NASA Exoplanet Archive	An et al. 2025	2025
5.922	au	± 0.035	Radial Velocity	NASA Exoplanet Archive	Giovinazzi et al. 2025	2025
5.942	au	± 0.083	Radial Velocity	NASA Exoplanet Archive	Rosenthal et al. 2021	2021
6.074	au	± 0.08	Radial Velocity	NASA Exoplanet Archive	Feng et al. 2015	2015
5.32	au	± 0.38	Radial Velocity	NASA Exoplanet Archive	Wright et al. 2009	2009
4.41	au	± 0.21	Radial Velocity	NASA Exoplanet Archive	Wittenmyer et al. 2007	2007
4.3	au	± 2	Radial Velocity	NASA Exoplanet Archive	Vogt et al. 2005	2005

Eccentricity 8 values

Value	Uncertainty	Band / method	Source	Reference	Year
0.3908	± 0.0082	Radial Velocity	NASA Exoplanet Archive	An et al. 2025	2025
0.3918	± 0.0064	Radial Velocity	NASA Exoplanet Archive	Giovinazzi et al. 2025	2025
0.3928	± 0.0069	Radial Velocity	NASA Exoplanet Archive	Rosenthal et al. 2021	2021
0.376	± 0.014	Radial Velocity	NASA Exoplanet Archive	Bryan et al. 2016	2016
0.3848	± 0.0086	Radial Velocity	NASA Exoplanet Archive	Feng et al. 2015	2015
0.517	± 0.033	Radial Velocity	NASA Exoplanet Archive	Wright et al. 2009	2009
0.537	± 0.026	Radial Velocity	NASA Exoplanet Archive	Wittenmyer et al. 2007	2007
0.55	± 0.2	Radial Velocity	NASA Exoplanet Archive	Vogt et al. 2005	2005

In the same field

within 9 arcmin · wider search

Object	Type	Separation	V
HD 217107 b	Exoplanet	0″	6.155
HD 217107	**	0.2558″	6.163
LEDA 1092606	Seyfert2	108.1″	—
SDSS J225803.78-022742.6	QSO	296.9″	—
LEDA 1095123	Seyfert1	313.9″	—
LEDA 1095194	EmissionG	460.8″	—
CRTS J225743.5-022452	RRLyrae	483.5″	15.48
SDSS J225819.05-021540.8	QSO	485.6″	—

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/hd-217107-c · Registry entry updated 2026-08-14.