Planet K2-139 Ab

Detailed information about planet K2-139 Ab and its parameters.

Planet parameters Publications Observability Predictor

Planet

Name

K2-139 Ab

Planet Status

Confirmed

Discovered in

2017

Publication Status

Published in a refereed paper

Update

2025-09-04

Mass

0.381 (\begin{matrix} + 0.045 \\ - 0.045 \end{matrix})

M_J 1 publication

K2-139 b: a low-mass warm Jupiter on a 29-day orbit transiting an active K0 V star

Mass*sin(i)

—

Semi-Major Axis

0.1796 (\begin{matrix} + 0.0015 \\ - 0.0015 \end{matrix})

AU 1 publication

Sixty Validated Planets from K2 Campaigns 5-8

Orbital Period

28.380619 (\begin{matrix} + 0.000551 \\ - 0.000528 \end{matrix})

day 1 publication

Sixty Validated Planets from K2 Campaigns 5-8

Eccentricity

0.0 1 publication

K2-139 b: a low-mass warm Jupiter on a 29-day orbit transiting an active K0 V star

Angular distance

—

ω

—

T_peri

—

Radius

0.813 (\begin{matrix} + 0.015 \\ - 0.015 \end{matrix})

R_J 1 publication

Sixty Validated Planets from K2 Campaigns 5-8

Inclination

89.55 (\pm 0.13)

deg 1 publication

K2-139 b: a low-mass warm Jupiter on a 29-day orbit transiting an active K0 V star

Detection Method

Primary Transit

Mass Meas. Method

Radial Velocity

Radius Meas. Method

Primary Transit

Primary transit

2457325.81705 (\pm 0.00033)

JD 1 publication

K2-139 b: a low-mass warm Jupiter on a 29-day orbit transiting an active K0 V star

Secondary transit

—

λ

—

Impact Parameter b

0.17 (\begin{matrix} + 0.16 \\ - 0.12 \end{matrix})

1 publication

Sixty Validated Planets from K2 Campaigns 5-8

Time V_r=0

—

Velocity Semiamplitude K

26.9 (\pm 3.2)

m/s 1 publication

K2-139 b: a low-mass warm Jupiter on a 29-day orbit transiting an active K0 V star

Calculated temperature

524.0 (\begin{matrix} + 8.0 \\ - 8.0 \end{matrix})

K 1 publication

Sixty Validated Planets from K2 Campaigns 5-8

Measured temperature

—

Hottest point longitude

—

Geometric albedo

—

Surface gravity log(g/g_H)

—

Alternate Names

2MASS J19161596-1754384 b, EPIC 218916923 b, EPIC 218916923.01, TYC 6300-2008-1 b, WISE J191615.99-175438.5 b

Data Source	Type	Result Value	Result Figure	Notes	Reference

Molecule	Data Source	Type	Result Value	Result Figure	Notes	Reference

1 Sep 2025: See also Planets in Binaries webpage.

No link

Star

Name

K2-139 A

Distance

153.856 (\begin{matrix} + 0.932 \\ - 0.921 \end{matrix})

pc 1 publication

The Revised TESS Input Catalog and Candidate Target List

Spectral type

G9/K0V

Apparent magnitude V

11.7

Apparent magnitude I

—

Apparent magnitude J

—

Apparent magnitude H

—

Apparent magnitude K

—

Mass

0.882 (\begin{matrix} + 0.135 \\ - 0.085 \end{matrix})

M_Sun 1 publication

The Revised TESS Input Catalog and Candidate Target List

Age

1.8 (\pm 0.3)

Gyr 2 publications

K2-139 b: a low-mass warm Jupiter on a 29-day orbit transiting an active K0 V star
K2-139 b: a low-mass warm Jupiter on a 29-day orbit transiting an active K0 V star

Effective temperature

5195.0 (\begin{matrix} + 144.8 \\ - 126.7 \end{matrix})

K 1 publication

The Revised TESS Input Catalog and Candidate Target List

Radius

0.893 (\begin{matrix} + 0.063 \\ - 0.046 \end{matrix})

R_Sun 1 publication

The Revised TESS Input Catalog and Candidate Target List

Metallicity [Fe/H]

0.22 (\pm 0.08)

1 publication

K2-139 b: a low-mass warm Jupiter on a 29-day orbit transiting an active K0 V star

Detected Disc

—

Magnetic Field

—

RA₂₀₀₀

19:16:16.0

Dec₂₀₀₀

-17:54:38.5

Alternate Names

2MASS J19161596-1754384, EPIC 218916923, TYC 6300-2008-1, WISE J191615.99-175438.5

Eeles-Nolle & Armstrong (2025): A faint companion star, likely a very low-mass M dwarf (Gaia DR3 4084602585291541888, G = 20.26), lies 59.33 arcseconds away (9,137 AUs at 154 pc).

No link

Simbad
Most recent references (ADS)

Planet K2-139 Ab

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 1 planet

Remarks Some remarks

Other web pages No page

More data 2 references

Planet K2-139 Ab

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 1 planet

Remarks Some remarks

Other web pages No page

More data 2 references

Related publications

A high stellar multiplicity rate amongst TESS planet candidates in the Neptunian desert using Gaia DR3 astrometry

The Spin–Orbit Alignment of Eight Warm Gas Giant Systems

High-resolution transmission spectroscopy of warm Jupiters: An ESPRESSO sample with predictions for ANDES

High-resolution Transmission Spectroscopy of Warm Jupiters: An ESPRESSO Sample with Predictions for ANDES

A CHEOPS Search for Massive, Long-Period Companions to the Warm Jupiter K2-139 b

The Revised TESS Input Catalog and Candidate Target List

K2-139 b: a low-mass warm Jupiter on a 29-day orbit transiting an active K0 V star

Sixty Validated Planets from K2 Campaigns 5-8