Key parameters at a glance

A radius of 1.91 Earth radii
A mass of 4.31 Earth masses
Surface gravity around 1.18 g
An orbital period of 13.151 days
Semi-major axis 0.1182 AU
Equilibrium temperature 1,008 K (735 °C)
Distance from Earth 1,572.23 light-years
Earth Similarity Index 0.274
Travel time at Voyager 1 speed 27,726,190 years

Kepler-1121 b Planet Profile

Physical Specs

Radius

1.91 R⊕

Radius (Jupiter)

0.170 R♃

Mass

4.31 M⊕

Mass (Jupiter)

0.014 M♃

Density

3.40 g/cm³

Surface Gravity

1.18 g (Earth)

Classification

Planet Type

Super-Earth

ESI Score 0.274

HZ Position Inner

Controversial No

Discovery

Year 2016

Method Transit

Facility Kepler

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#114of 1176

top 9.6%

This planet

1.91R⊕

Super-Earth median

1.60R⊕

Nearest-size peers

Kepler-524 b 1.91 R⊕ Kepler-1306 b 1.91 R⊕ Kepler-753 b 1.91 R⊕

Metric	Earth	Kepler-1121 b	Jupiter
Radius (R⊕)	1.00	1.91	11.21
Mass (M⊕)	1.00	4.31	317.83
Density (g/cm³)	5.51	3.40	1.33
Surface Gravity (g)	1.00	1.18	2.53
Insolation (S⊕)	1.00	205.27	0.037

Star Catalogue Identifiers

TIC

TIC 28230581

Gaia DR2

Gaia DR2 2086505630781210752

Gaia DR3

Gaia DR3 2086505630781210752

System

Kepler-1121

Percentile among Super-Earth cohort

Radius 1.910 R⊕ · percentile 90 / cohort 1176

Mass 4.310 M⊕ · percentile 83 / cohort 1176

Orbital period 13.15 d · percentile 73 / cohort 1164

Distance 482.05 pc · percentile 46 / cohort 1171

ESI 0.274 · percentile 30 / cohort 1176

Orbit & Habitability

Orbital Dynamics

Period

13.151 days

Semi-major axis

0.1182 AU

Eccentricity

0.000

Inclination

84.73 °

Year Length

A year here lasts approximately 13.15 Earth days (3.6% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1182 AU.

Transit Fingerprint

Depth

0.009 %

Duration

5.604 h

Impact parameter b

0.744

Rp / R★

0.010779

Transit midpoint (BJD)

2,454,977.1611

Photometric dip

Transit produces a flux drop of 95 ppm lasting ≈ 5.60 h.

Extended Orbital Architecture

Planet / star radius ratio

0.010779

Semi-major axis / stellar radius

12.800

Impact parameter (b)

0.744

Transit mid-time (BJD)

2,454,977.1611

Angular separation (arcsec)

0.24500

Eq. Temperature

1,008K

(735 °C)

Insolation (S⊕)

205.27

Earth = 1.00

Earth Similarity (ESI)

0.274

0 = alien, 1 = Earth-identical

Inside the inner HZ boundary (too hot for liquid water) — the dayside is scorched.

Discovery Paper

Primary reference

Morton et al. 2016

Instrument

Kepler CCD Array

Publication

2016-05

Observation locale

Space

Discovery cohort

Planets confirmed in 2016 at Kepler (12 shown).

Kepler-1512 b · Rocky Terrestrial Kepler-1410 b · Super-Earth Kepler-560 b · Super-Earth Kepler-1389 b · Super-Earth Kepler-1450 b · Super-Earth Kepler-1544 b · Super-Earth Kepler-1459 b · Super-Earth Kepler-1638 b · Super-Earth Kepler-737 b · Super-Earth Kepler-1185 b · Super-Earth Kepler-1178 b · Rocky Terrestrial Kepler-1040 b · Sub-Neptune

Host System: Kepler-1121

Spectral Class

F-type yellow-white

Effective Temperature

6,231 K — hotter than the Sun (5,778 K)

Estimated Age

3.02 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

1.590 R☉

Stellar Mass

1.290 M☉

Metallicity [Fe/H]

0.12

Extended Stellar Properties

Surface gravity (log g)

4.140 dex

Stellar density

0.420 g/cm³

Systemic radial velocity

-33.94 km/s

Metallicity ratio

[Fe/H]

Distance

482.05 parsec

Light-years 1,572.23 ly

V-band magnitude

12.14 mag

Voyager-speed travel 27,726,190 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

2.046 mas

Total Proper Motion

7.320 mas/yr

PM Right Ascension

0.89 mas/yr

PM Declination

7.27 mas/yr

Galactic Cartesian (pc)

x = 0.313 · y = -0.593 · z = 0.742

Equatorial (J2000)

RA 297.78655° · Dec 47.88615°

Galactic ℓ, b

81.686° · 10.633°

Ecliptic λ, β

321.432° · 66.433°

HTM-20 index

1169326429