Planet LP 261-75 b

Detailed information about planet LP 261-75 b and its parameters.

Planet parameters Publications Observability Predictor

Planet

Name

LP 261-75 b

Planet Status

Confirmed

Discovered in

2006

Publication Status

Published in a refereed paper

Update

2025-09-25

Mass

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

M_J 1 publication

LP 261‐75/2MASSW J09510549+3558021: A Young, Wide M4.5/L6 Binary

Mass*sin(i)

—

Semi-Major Axis

450.0 (\pm 120.0)

AU 1 publication

LP 261‐75/2MASSW J09510549+3558021: A Young, Wide M4.5/L6 Binary

Orbital Period

—

Eccentricity

—

Angular distance

—

ω

—

T_peri

—

Radius

—

Inclination

—

Detection Method

Imaging

Mass Meas. Method

Spectrum

Radius Meas. Method

—

Primary transit

—

Secondary transit

—

λ

—

Impact Parameter b

—

Time V_r=0

—

Velocity Semiamplitude K

—

Calculated temperature

1500.0 (\pm 50.0)

K 1 publication

LP 261‐75/2MASSW J09510549+3558021: A Young, Wide M4.5/L6 Binary

Measured temperature

—

Hottest point longitude

—

Geometric albedo

—

Surface gravity log(g/g_H)

—

Alternate Names

RED 13 b, TOI-1779 b, 2MASS J09510459+3558098 b

Data Source	Type	Result Value	Result Figure	Notes	Reference

Molecule	Data Source	Type	Result Value	Result Figure	Notes	Reference

Spectral type L6.

No link

Star

Name

LP 261-75

Distance

33.995 (\pm 0.028)

pc 1 publication

A Small Brown Dwarf in an Aligned Orbit around a Young, Fully-Convective M Star

Spectral type

M4.5V

Apparent magnitude V

15.33

Apparent magnitude I

—

Apparent magnitude J

—

Apparent magnitude H

—

Apparent magnitude K

—

Mass

0.3 (\pm 0.015)

M_Sun 2 publications

The Brown Dwarf Kinematics Project. II. Details on Nine Wide Common Proper Motion Very Low Mass Companions to Nearby Stars
A Small Brown Dwarf in an Aligned Orbit around a Young, Fully-Convective M Star

Age

0.15 (\pm 0.05)

Gyr 1 publication

The Brown Dwarf Kinematics Project. II. Details on Nine Wide Common Proper Motion Very Low Mass Companions to Nearby Stars

Effective temperature

3138.0 (\pm 157.0)

K 1 publication

A Small Brown Dwarf in an Aligned Orbit around a Young, Fully-Convective M Star

Radius

0.308 (\pm 0.005)

R_Sun 1 publication

A Small Brown Dwarf in an Aligned Orbit around a Young, Fully-Convective M Star

Metallicity [Fe/H]

—

Detected Disc

—

Magnetic Field

—

RA₂₀₀₀

09:51:04.6

Dec₂₀₀₀

+35:58:09.5

Alternate Names

NLTT 22741, TOI-1779, 2MASS J09510459+3558098

LP 261-75 forms an eclipsing binary with a close-in (P = 1.882 d) brown dwarf companion (m₂ = 67.4 ± 2.1 M_Jup, r₂ = 0.91 R_Jup, i = 89.131 ± 0.065°, see also Irwin et al. 2018, Brady et al. 2024).
The transiting brown dwarf is labeled as TOI-1779.01 and LP 261-75 C, since the outermost imaged substellar companion was the first one discovered and named “LP 261-75 B”. Hence according to naming conventions the binary system should be mentioned as LP 261-75 (AC).
On the other hand if the outer companion is regarded as “planet” in broad sense and the inner one as very low-mass star at stellar/substellar boundary, the binary system might be mentioned as “LP 261-75 (AB)” and the outer companion as “(AB)b”.