Planet 51 Peg c

Detailed information about planet 51 Peg c and its parameters.

Planet parameters Publications Observability Predictor

Planet

Name

51 Peg c

Planet Status

Confirmed

Discovered in

2011

Publication Status

—

Update

2026-05-13

Mass

10.0 (\begin{matrix} + 5.0 \\ - 9.0 \end{matrix})

M_J 2 publications

An Outer Giant Planet or Brown Dwarf in the 51 Pegasi System?
Stellar and substellar companions of nearby stars from Gaia DR2. Binarity from proper motion anomaly

Mass*sin(i)

—

Semi-Major Axis

37.0 (\begin{matrix} + 20.0 \\ - 15.0 \end{matrix})

AU 3 publications

An Outer Giant Planet or Brown Dwarf in the 51 Pegasi System?
Stellar and substellar companions of nearby stars from Gaia DR2. Binarity from proper motion anomaly
Know the Star, Know the Planet. I. Adaptive Optics of Exoplanet Host Stars

Orbital Period

—

Eccentricity

—

Angular distance

—

ω

—

T_peri

—

Radius

—

Inclination

—

Detection Method

Imaging, Astrometry

Mass Meas. Method

Astrometry

Radius Meas. Method

—

Primary transit

—

Secondary transit

—

λ

—

Impact Parameter b

—

Time V_r=0

—

Velocity Semiamplitude K

—

Calculated temperature

—

Measured temperature

—

Hottest point longitude

—

Geometric albedo

—

Surface gravity log(g/g_H)

—

Alternate Names

—

Data Source	Type	Result Value	Result Figure	Notes	Reference

Molecule	Data Source	Type	Result Value	Result Figure	Notes	Reference

No remarks

No link

Star

Name

51 Peg

Distance

15.4614 (\pm 0.0297)

Spectral type

G2IV-V

Apparent magnitude V

5.49

Apparent magnitude I

—

Apparent magnitude J

—

Apparent magnitude H

—

Apparent magnitude K

—

Mass

1.03 (\pm 0.126)

M_Sun 1 publication

Solar-type stars with planetary companions: 51 Pegasi and 47 Ursae Majoris

Age

4.0 (\pm 2.5)

Gyr 1 publication

Solar-type stars with planetary companions: 51 Pegasi and 47 Ursae Majoris

Effective temperature

5758.0 (\pm 110.623)

K 1 publication

Solar-type stars with planetary companions: 51 Pegasi and 47 Ursae Majoris

Radius

1.176 (\pm 0.051)

R_Sun 1 publication

Eleven Exoplanet Host Star Angular Diameters from the Chara Array

Metallicity [Fe/H]

0.18 (\pm 0.1)

1 publication

Solar-type stars with planetary companions: 51 Pegasi and 47 Ursae Majoris

Detected Disc

—

Magnetic Field

—

RA₂₀₀₀

22:57:27.0

Dec₂₀₀₀

+20:46:07.0

Alternate Names

HD 217014

Roberts et al. (2011) reported a visual companion at a projected separation of 2.87 arcseconds, about 44-45 AUs. Kervella et al. (2019) estimate a mass of m ≈ 70_-40⁺⁷⁰ M_Jup, compatible with an early T-type brown dwarf. The visual companion may be gravitationally bound to 51 Peg, although further characterization is needed to confirm this.

No link