Registry · exoplanet

55 Cnc B 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 40.30s
Declination: +28° 18′ 55.0″
Galactic l, b: 196.82, 37.71
Magnitude V: 13.15
Distance: 12.477 pc

Planet

NASA Exoplanet Archive, composite parameters

Host star	55 Cnc B · M4.5 V
Discovery	Radial Velocity, 2025 · Mauna Kea Observatory
Orbital period	6.7994 d
Semi-major axis	0.044 au
Eccentricity	0
Radius	1.69 R⊕ · 0.151 R♃
Mass	3.5 M⊕ · 0.01101 M♃
Density	3.98 g/cm³
Equilibrium temperature	395.41 K
System distance	12.477 pc

Recorded parameters

4 quantities with a single published value

Parameter	Value	Unit	Uncertainty	As published	Source	Reference
Mass	3.5	M_earth	± 0.8	Radial Velocity	NASA Exoplanet Archive	Moutou et al. 2026
Orbital period	6.7994	d	± 0.0013	Radial Velocity	NASA Exoplanet Archive	Moutou et al. 2026
Semi-major axis	0.044	au	± 0.0012	Radial Velocity	NASA Exoplanet Archive	Moutou et al. 2026
Eccentricity	0			Radial Velocity	NASA Exoplanet Archive	Moutou et al. 2026

In the same field

within 9 arcmin · wider search

Object	Type	Separation	V
55 Cnc B	Star	0″	—
55 Cnc B c	Exoplanet	0″	13.15
* rho01 Cnc B	HighPM*	8.367″	—
* rho01 Cnc f	Planet	81.47″	—
* rho01 Cnc e	Planet	81.47″	—
* rho01 Cnc	HighPM*	81.47″	—
* rho01 Cnc b	Planet	81.47″	—
* rho01 Cnc c	Planet	81.47″	—
* rho01 Cnc d	Planet	81.47″	—
55 Cnc	Star	84.82″	—
55 Cnc b	Exoplanet	84.82″	5.951

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-b · Registry entry updated 2026-08-14.