Registry · exoplanet

55 Cnc b

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: 08h 52m 35.24s
Declination: +28° 19′ 47.3″
Galactic l, b: 196.8, 37.7
Magnitude V: 5.951
Distance: 12.585 pc

Planet

NASA Exoplanet Archive, composite parameters

Host star	55 Cnc · G8 V
Discovery	Radial Velocity, 1996 · Lick Observatory
Orbital period	14.6516 d
Semi-major axis	0.118 au
Eccentricity	0.0029
Radius	13.9 R⊕ · 1.24 R♃
Mass	263.98 M⊕ · 0.8306 M♃
Density	0.54 g/cm³
Equilibrium temperature	700 K
System distance	12.585 pc

Recorded parameters

1 quantity with a single published value

Parameter	Value	Unit	Uncertainty	As published	Source	Reference
Equilibrium temperature	700	K		Radial Velocity	NASA Exoplanet Archive	Salz et al. 2015

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 14 values

Value	Unit	Uncertainty	Band / method	Source	Reference	Year
276	M_earth	± 9	Radial Velocity	NASA Exoplanet Archive	Moutou et al. 2026	2026
240	M_earth	± 9.6	Radial Velocity	NASA Exoplanet Archive	Harada et al. 2025	2025
267.2937	M_earth	± 8.264	Radial Velocity	NASA Exoplanet Archive	Rosenthal et al. 2021	2021
255.4	M_earth	± 2.9	Radial Velocity	NASA Exoplanet Archive	Bourrier et al. 2018	2018
263.9785	M_earth	± 1.049	Radial Velocity	NASA Exoplanet Archive	Baluev 2015	2015
254.25	M_earth		Radial Velocity	NASA Exoplanet Archive	Salz et al. 2015	2015
266.966	M_earth	± 41.63	Radial Velocity	NASA Exoplanet Archive	Nelson et al. 2014	2014
254.25	M_earth	± 3.814	Radial Velocity	NASA Exoplanet Archive	Endl et al. 2012	2012
260.61	M_earth	± 38.14	Radial Velocity	NASA Exoplanet Archive	Wright et al. 2009	2009
261.881	M_earth	± 2.225	Radial Velocity	NASA Exoplanet Archive	Fischer et al. 2008	2008
289.21	M_earth	± 6.36	Radial Velocity	NASA Exoplanet Archive	Naef et al. 2004	2004
249.1787	M_earth	± 28.6	Radial Velocity	NASA Exoplanet Archive	McArthur et al. 2004	2004

Show the remaining 2

Value	Unit	Uncertainty	Band / method	Source	Reference	Year
266.9772	M_earth	± 22.25	Radial Velocity	NASA Exoplanet Archive	Marcy et al. 2002	2002
266.9772	M_earth		Radial Velocity	NASA Exoplanet Archive	Butler et al. 1997	1997

Orbital period 14 values

Value	Unit	Uncertainty	Band / method	Source	Reference	Year
14.65155	d	± 3.60e-05	Radial Velocity	NASA Exoplanet Archive	Moutou et al. 2026	2026
14.65161	d	± 6.00e-05	Radial Velocity	NASA Exoplanet Archive	Harada et al. 2025	2025
14.65171	d	± 5.30e-05	Radial Velocity	NASA Exoplanet Archive	Rosenthal et al. 2021	2021
14.6516	d	± 0.0001	Radial Velocity	NASA Exoplanet Archive	Bourrier et al. 2018	2018
14.65152	d	± 0.00015	Radial Velocity	NASA Exoplanet Archive	Baluev 2015	2015
14.6	d		Radial Velocity	NASA Exoplanet Archive	Salz et al. 2015	2015
14.46531	d	± 0.0009	Radial Velocity	NASA Exoplanet Archive	Nelson et al. 2014	2014
14.651	d	± 0.0001	Radial Velocity	NASA Exoplanet Archive	Endl et al. 2012	2012
14.65126	d	± 0.0007	Radial Velocity	NASA Exoplanet Archive	Wright et al. 2009	2009
14.65162	d	± 0.0007	Radial Velocity	NASA Exoplanet Archive	Fischer et al. 2008	2008
14.647	d	± 0.001	Radial Velocity	NASA Exoplanet Archive	Naef et al. 2004	2004
14.67	d	± 0.01	Radial Velocity	NASA Exoplanet Archive	McArthur et al. 2004	2004

Show the remaining 2

Value	Unit	Uncertainty	Band / method	Source	Reference	Year
14.653	d	± 0.0006	Radial Velocity	NASA Exoplanet Archive	Marcy et al. 2002	2002
14.648	d	± 0.0009	Radial Velocity	NASA Exoplanet Archive	Butler et al. 1997	1997

Semi-major axis 14 values

Value	Unit	Uncertainty	Band / method	Source	Reference	Year
0.118	au	± 0.002	Radial Velocity	NASA Exoplanet Archive	Moutou et al. 2026	2026
0.1102	au	± 0.0022	Radial Velocity	NASA Exoplanet Archive	Harada et al. 2025	2025
0.1162	au	± 0.0018	Radial Velocity	NASA Exoplanet Archive	Rosenthal et al. 2021	2021
0.1134	au	± 0.0006	Radial Velocity	NASA Exoplanet Archive	Bourrier et al. 2018	2018
0.1152273	au	± 7.90e-07	Radial Velocity	NASA Exoplanet Archive	Baluev 2015	2015
0.113	au		Radial Velocity	NASA Exoplanet Archive	Salz et al. 2015	2015
0.11339	au	± 0.00011	Radial Velocity	NASA Exoplanet Archive	Nelson et al. 2014	2014
0.1134	au	± 0.0006	Radial Velocity	NASA Exoplanet Archive	Endl et al. 2012	2012
0.1138	au	± 0.0066	Radial Velocity	NASA Exoplanet Archive	Wright et al. 2009	2009
0.115	au	± 1.10e-06	Radial Velocity	NASA Exoplanet Archive	Fischer et al. 2008	2008
0.115	au		Radial Velocity	NASA Exoplanet Archive	Naef et al. 2004	2004
0.115	au	± 0.003	Radial Velocity	NASA Exoplanet Archive	McArthur et al. 2004	2004

Show the remaining 2

Value	Unit	Uncertainty	Band / method	Source	Reference	Year
0.115	au	± 0.003	Radial Velocity	NASA Exoplanet Archive	Marcy et al. 2002	2002
0.11	au		Radial Velocity	NASA Exoplanet Archive	Butler et al. 1997	1997

Eccentricity 14 values

Value	Uncertainty	Band / method	Source	Reference	Year
0.0029	± 0.0027	Radial Velocity	NASA Exoplanet Archive	Moutou et al. 2026	2026
0.0026	± 0.0028	Radial Velocity	NASA Exoplanet Archive	Harada et al. 2025	2025
0.0048	± 0.0036	Radial Velocity	NASA Exoplanet Archive	Rosenthal et al. 2021	2021
0	± 0.01	Radial Velocity	NASA Exoplanet Archive	Bourrier et al. 2018	2018
0.0034	± 0.0032	Radial Velocity	NASA Exoplanet Archive	Baluev 2015	2015
0		Radial Velocity	NASA Exoplanet Archive	Salz et al. 2015	2015
0.0023	± 0.0025	Radial Velocity	NASA Exoplanet Archive	Nelson et al. 2014	2014
0.004	± 0.003	Radial Velocity	NASA Exoplanet Archive	Endl et al. 2012	2012
0.0159	± 0.008	Radial Velocity	NASA Exoplanet Archive	Wright et al. 2009	2009
0.014	± 0.008	Radial Velocity	NASA Exoplanet Archive	Fischer et al. 2008	2008
0.03	± 0.023	Radial Velocity	NASA Exoplanet Archive	Naef et al. 2004	2004
0.0197	± 0.012	Radial Velocity	NASA Exoplanet Archive	McArthur et al. 2004	2004

Show the remaining 2

Value	Unit	Uncertainty	Band / method	Source	Reference	Year
0.02		± 0.02	Radial Velocity	NASA Exoplanet Archive	Marcy et al. 2002	2002
0.051		± 0.013	Radial Velocity	NASA Exoplanet Archive	Butler et al. 1997	1997

In the same field

within 9 arcmin · wider search

Object	Type	Separation	V
55 Cnc	Star	0″	—
55 Cnc f	Exoplanet	0″	5.951
55 Cnc e	Exoplanet	0″	5.951
55 Cnc d	Exoplanet	0″	5.951
55 Cnc c	Exoplanet	0″	5.951
* rho01 Cnc f	Planet	8.353″	—
* rho01 Cnc e	Planet	8.353″	—
* rho01 Cnc	HighPM*	8.353″	—
* rho01 Cnc b	Planet	8.353″	—
* rho01 Cnc c	Planet	8.353″	—
* rho01 Cnc d	Planet	8.353″	—

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/55-cnc-b · Registry entry updated 2026-08-14.