Planet GJ 229 Bb

Detailed information about planet GJ 229 Bb and its parameters.

Planet parameters Publications Observability Predictor

Planet

Name

GJ 229 Bb

Planet Status

Confirmed

Discovered in

2021

Publication Status

—

Update

2025-02-28

Mass

33.4 (\pm 1.1)

M_J 2 publications

On the Orbit of the Binary Brown Dwarf Companion GL229 Ba and Bb
The cool brown dwarf Gliese 229 B is a close binary

Mass*sin(i)

—

Semi-Major Axis

0.0424 (\pm 0.0004)

AU 1 publication

The cool brown dwarf Gliese 229 B is a close binary

Orbital Period

12.1346 (\pm 0.001)

day 2 publications

On the Orbit of the Binary Brown Dwarf Companion GL229 Ba and Bb
The cool brown dwarf Gliese 229 B is a close binary

Eccentricity

0.2317 (\pm 0.0025)

2 publications

On the Orbit of the Binary Brown Dwarf Companion GL229 Ba and Bb
The cool brown dwarf Gliese 229 B is a close binary

Angular distance

—

ω

— 1 publication

The cool brown dwarf Gliese 229 B is a close binary

T_peri

—

Radius

—

Inclination

31.4 (\pm 0.3)

deg 1 publication

The cool brown dwarf Gliese 229 B is a close binary

Detection Method

Astrometry, Imaging

Mass Meas. Method

Astrometry

Radius Meas. Method

—

Primary transit

—

Secondary transit

—

λ

—

Impact Parameter b

—

Time V_r=0

—

Velocity Semiamplitude K

—

Calculated temperature

770.0 (\pm 20.0)

K 1 publication

The cool brown dwarf Gliese 229 B is a close binary

Measured temperature

—

Hottest point longitude

—

Geometric albedo

—

Surface gravity log(g/g_H)

—

Alternate Names

gl 229 Bb

Data Source	Type	Result Value	Result Figure	Notes	Reference

Molecule	Data Source	Type	Result Value	Result Figure	Notes	Reference

11 Feb 2025
The GJ 229 B system has a semi-major axis of 42.9 AU around GJ 229 A (Thompson et al. 2025)

No link

Star

Name

GJ 229

Distance

5.75624 (\pm 0.001525)

pc 1 publication

The Revised TESS Input Catalog and Candidate Target List

Spectral type

M1V

Apparent magnitude V

8.125

Apparent magnitude I

—

Apparent magnitude J

—

Apparent magnitude H

—

Apparent magnitude K

—

Mass

0.544 (\pm 0.041)

M_Sun 2 publications

Search for Nearby Earth Analogs. II. detection of five new planets, eight planet candidates, and confirmation of three planets around nine nearby M dwarfs
The Revised TESS Input Catalog and Candidate Target List

Age

2.45 (\pm 0.2)

Gyr 1 publication

The cool brown dwarf Gliese 229 B is a close binary

Effective temperature

3564.0 K 1 publication

Bayesian search for low-mass planets around nearby M dwarfs. Estimates for occurrence rate based on global detectability statistics

Radius

0.548 (\pm 0.043)

R_Sun 1 publication

The Revised TESS Input Catalog and Candidate Target List

Metallicity [Fe/H]

—

Detected Disc

—

Magnetic Field

—

RA₂₀₀₀

06:10:34.6

Dec₂₀₀₀

-21:51:52.7

Alternate Names

HD 42581, NAJ 1

No remarks

No link

Simbad
Most recent references (ADS)

Planet GJ 229 Bb

Planet

Basic informations 30 parameters

Atmospheric parameters : Temperatures 0 temperatures

Atmospheric parameters : Molecules 0 molecules

Remarks Some remarks

Other web pages No page

Star

Basic informations 17 parameters

Planetary system 4 planets

Remarks No remark

Other web pages No page

More data 2 references

Planet GJ 229 Bb

Planet

Basic informations 30 parameters

Atmospheric parameters : Temperatures 0 temperatures

Atmospheric parameters : Molecules 0 molecules

Remarks Some remarks

Other web pages No page

Star

Basic informations 17 parameters

Planetary system 4 planets

Remarks No remark

Other web pages No page

More data 2 references

Related publications

The Gl 229 System Revisited with the Line-by-line Framework: Planetary Signals Now Appear as Stellar Activity Ghosts

On the Orbit of the Binary Brown Dwarf Companion GL229 Ba and Bb

Lessons learned from the detection of wide companions by radial velocity and astrometry

Atmospheric abundances and bulk properties of the binary brown dwarf Gliese 229 Bab from JWST/MIRI spectroscopy

Discovery of the Binarity of Gliese 229B, and Constraints on the System's Properties

The cool brown dwarf Gliese 229 B is a close binary

Improved Dynamical Masses for Six Brown Dwarf Companions Using Hipparcos and Gaia EDR3

Search for Nearby Earth Analogs. II. detection of five new planets, eight planet candidates, and confirmation of three planets around nine nearby M dwarfs

The Revised TESS Input Catalog and Candidate Target List

Physical Properties of Gliese 229B Based on Newly Determined Carbon and Oxygen Abundances of Gliese 229A

Bayesian search for low-mass planets around nearby M dwarfs. Estimates for occurrence rate based on global detectability statistics