Planet KELT-20 Ac

Detailed information about planet KELT-20 Ac and its parameters.

Planet parameters Publications Observability Predictor

Planet

Name

KELT-20 Ac

Planet Status

Confirmed

Discovered in

2026

Publication Status

—

Update

2026-06-03

Mass

34.0 (\begin{matrix} + 29.0 \\ - 11.0 \end{matrix})

M_J 1 publication

A Massive Hot-Jupiter Companion that Disfavors Giant Planet Formation Beyond the Water-Ice Line

Mass*sin(i)

—

Semi-Major Axis

6.6 (\begin{matrix} + 4.8 \\ - 3.4 \end{matrix})

AU 1 publication

A Massive Hot-Jupiter Companion that Disfavors Giant Planet Formation Beyond the Water-Ice Line

Orbital Period

4380.0 (\begin{matrix} + 5475.0 \\ - 2190.0 \end{matrix})

day 1 publication

A Massive Hot-Jupiter Companion that Disfavors Giant Planet Formation Beyond the Water-Ice Line

Eccentricity

0.43 (\begin{matrix} + 0.34 \\ - 0.3 \end{matrix})

1 publication

A Massive Hot-Jupiter Companion that Disfavors Giant Planet Formation Beyond the Water-Ice Line

Angular distance

—

ω

3.4 (\pm 1.5)

deg 1 publication

A Massive Hot-Jupiter Companion that Disfavors Giant Planet Formation Beyond the Water-Ice Line

T_peri

—

Radius

—

Inclination

1.5 (\begin{matrix} + 1.0 \\ - 0.9 \end{matrix})

deg 1 publication

A Massive Hot-Jupiter Companion that Disfavors Giant Planet Formation Beyond the Water-Ice Line

Detection Method

Radial Velocity, Astrometry, TTV

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

MASCARA-2 Ac, HD 185603 c

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

KELT-20 A

Distance

136.426 (\begin{matrix} + 0.816 \\ - 0.807 \end{matrix})

pc 1 publication

The Revised TESS Input Catalog and Candidate Target List

Spectral type

A2V

Apparent magnitude V

7.58

Apparent magnitude I

—

Apparent magnitude J

—

Apparent magnitude H

—

Apparent magnitude K

—

Mass

2.0 (\begin{matrix} + 0.2 \\ - 0.1 \end{matrix})

M_Sun 1 publication

KELT-20b: A giant planet with a period of P~ 3.5 days transiting the V~ 7.6 early A star HD 185603

Age

0.3 (\begin{matrix} + 0.2 \\ - 0.1 \end{matrix})

Gyr

Effective temperature

8981.0 (\pm 115.0)

K 1 publication

KELT-20b: A giant planet with a period of P~ 3.5 days transiting the V~ 7.6 early A star HD 185603

Radius

1.561 (\begin{matrix} + 0.058 \\ - 0.064 \end{matrix})

R_Sun 1 publication

KELT-20b: A giant planet with a period of P~ 3.5 days transiting the V~ 7.6 early A star HD 185603

Metallicity [Fe/H]

-0.29 (\begin{matrix} + 0.22 \\ - 0.36 \end{matrix})

1 publication

KELT-20b: A giant planet with a period of P~ 3.5 days transiting the V~ 7.6 early A star HD 185603

Detected Disc

—

Magnetic Field

—

RA₂₀₀₀

19:38:38.7

Dec₂₀₀₀

+31:13:09.2

Alternate Names

SAO 68614, 2MASS J19383872+3113091

Eeles-Nolle & Armstrong (2025): A faint companion, possibly a brown dwarf (Gaia DR3 2033123757137339008, G = 20.75), lies 48.14 arcseconds away (6,595 AUs at 137 pc).

No link

Simbad
Most recent references (ADS)

Planet KELT-20 Ac

Planet

Basic informations 30 parameters

Atmospheric parameters : Temperatures 0 temperatures

Atmospheric parameters : Molecules 0 molecules

Remarks No remark

Other web pages No page

Star

Basic informations 17 parameters

Planetary system 2 planets

Remarks Some remarks

Other web pages No page

More data 2 references

Planet KELT-20 Ac

Planet

Basic informations 30 parameters

Atmospheric parameters : Temperatures 0 temperatures

Atmospheric parameters : Molecules 0 molecules

Remarks No remark

Other web pages No page

Star

Basic informations 17 parameters

Planetary system 2 planets

Remarks Some remarks

Other web pages No page

More data 2 references

Related publications

A Massive Hot-Jupiter Companion that Disfavors Giant Planet Formation Beyond the Water-Ice Line

The Revised TESS Input Catalog and Candidate Target List

KELT-20b: A giant planet with a period of P~ 3.5 days transiting the V~ 7.6 early A star HD 185603