Key parameters at a glance

A radius of 2.13 Earth radii
A mass of 5.19 Earth masses
Surface gravity around 1.14 g
An orbital period of 12.184 days
Semi-major axis 0.1030 AU
Equilibrium temperature 819 K (546 °C)
Distance from Earth 2,019.38 light-years
Earth Similarity Index 0.328
Travel time at Voyager 1 speed 35,611,797 years

Kepler-1777 b Planet Profile

Physical Specs

Radius

2.13 R⊕

Radius (Jupiter)

0.190 R♃

Mass

5.19 M⊕

Mass (Jupiter)

0.016 M♃

Density

2.94 g/cm³

Surface Gravity

1.14 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.328

HZ Position Inner

Controversial No

Discovery

Year 2021

Method Transit

Facility Kepler

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#1764of 1978

top 89.1%

This planet

2.13R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-200 b 2.13 R⊕ Kepler-214 c 2.13 R⊕ HD 40307 f 2.13 R⊕

Metric	Earth	Kepler-1777 b	Jupiter
Radius (R⊕)	1.00	2.13	11.21
Mass (M⊕)	1.00	5.19	317.83
Density (g/cm³)	5.51	2.94	1.33
Surface Gravity (g)	1.00	1.14	2.53
Insolation (S⊕)	1.00	71.30	0.037

Star Catalogue Identifiers

TIC

TIC 122374509

Gaia DR2

Gaia DR2 2051104586182508928

Gaia DR3

Gaia DR3 2051104586182508928

System

Kepler-1777

Percentile among Sub-Neptune cohort

Radius 2.132 R⊕ · percentile 11 / cohort 1978

Mass 5.190 M⊕ · percentile 12 / cohort 1978

Orbital period 12.18 d · percentile 42 / cohort 1946

Distance 619.15 pc · percentile 54 / cohort 1975

ESI 0.328 · percentile 34 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

12.184 days

Semi-major axis

0.1030 AU

Eccentricity

0.000

Inclination

88.36 °

Year Length

A year here lasts approximately 12.18 Earth days (3.3% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1030 AU.

Transit Fingerprint

Depth

0.052 %

Duration

2.447 h

Impact parameter b

0.977

Rp / R★

0.021149

Transit midpoint (BJD)

2,454,972.0590

Photometric dip

Transit produces a flux drop of 515 ppm lasting ≈ 2.45 h.

Extended Orbital Architecture

Planet / star radius ratio

0.021149

Semi-major axis / stellar radius

8.700

Impact parameter (b)

0.977

Transit mid-time (BJD)

2,454,972.0590

Angular separation (arcsec)

0.16600

Eq. Temperature

819K

(546 °C)

Insolation (S⊕)

71.30

Earth = 1.00

Earth Similarity (ESI)

0.328

0 = alien, 1 = Earth-identical

Inside the inner HZ boundary (too hot for liquid water) — the surface is too hot to retain surface water.

Discovery Paper

Primary reference

Valizadegan et al. 2022

Instrument

Kepler CCD Array

Publication

2022-02

Observation locale

Space

Discovery cohort

Planets confirmed in 2021 at Kepler (12 shown).

Kepler-1816 b · Super-Earth Kepler-1705 c · Sub-Neptune Kepler-1948 b · Rocky Terrestrial Kepler-196 d · Sub-Neptune Kepler-1853 b · Super-Earth Kepler-1840 b · Sub-Neptune Kepler-1881 b · Sub-Neptune Kepler-1858 b · Sub-Neptune Kepler-1874 b · Sub-Neptune Kepler-1802 c · Sub-Neptune Kepler-1749 b · Super-Earth Kepler-1849 b · Sub-Neptune

Host System: Kepler-1777

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,771 K — cooler than the Sun (5,778 K)

Estimated Age

0.46 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

1.068 R☉

Stellar Mass

0.984 M☉

Metallicity [Fe/H]

0.06

Extended Stellar Properties

Surface gravity (log g)

4.374 dex

Stellar density

2.240 g/cm³

Metallicity ratio

[Fe/H]

Distance

619.15 parsec

Light-years 2,019.38 ly

V-band magnitude

14.11 mag

Voyager-speed travel 35,611,797 yr

Multi-band Host Photometry — 17 bands

Astrometric Data

Parallax

1.586 mas

Total Proper Motion

3.503 mas/yr

PM Right Ascension

-3.44 mas/yr

PM Declination

0.66 mas/yr

Galactic Cartesian (pc)

x = 0.275 · y = -0.742 · z = 0.612

Equatorial (J2000)

RA 290.32865° · Dec 37.72312°

Galactic ℓ, b

69.952° · 10.806°

Ecliptic λ, β

302.151° · 58.914°

HTM-20 index

1874362334