Key parameters at a glance

A radius of 1.23 Earth radii
A mass of 2.04 Earth masses
Surface gravity around 1.35 g
An orbital period of 2.346 days
Semi-major axis 0.0318 AU
Equilibrium temperature 997 K (724 °C)
Distance from Earth 1,942.86 light-years
Earth Similarity Index 0.310
Travel time at Voyager 1 speed 34,262,261 years
Almost certainly tidally locked to its host star given the close orbit

3 siblings around Kepler-1987

Kepler-1987 b shares its host star with 3 other confirmed planets. Side-by-side measurements below.

Planet	Type	Radius (R⊕)	Mass (M⊕)	Period (d)	Eq. T (K)	Year
Kepler-1987 b this	Rocky Terrestrial	1.23	2.04	2.346	997	2023
Kepler-1987 c	Super-Earth	1.33	2.33	3.648	860	2023
Kepler-1987 d	Sub-Neptune	2.66	7.56	5.645	744	2023
Kepler-1987 e	Super-Earth	1.92	4.35	8.743	643	2023

Kepler-1987 b Planet Profile

Physical Specs

Radius

1.23 R⊕

Radius (Jupiter)

0.110 R♃

Mass

2.04 M⊕

Mass (Jupiter)

0.006 M♃

Density

6.02 g/cm³

Surface Gravity

1.35 g (Earth)

Classification

Planet Type

Rocky Terrestrial

ESI Score 0.310

HZ Position Inner

Controversial No

Discovery

Year 2023

Method Transit

Facility Kepler

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#17of 570

top 2.8%

This planet

1.23R⊕

Rocky Terrestrial median

1.01R⊕

Nearest-size peers

Kepler-252 b 1.23 R⊕ Kepler-271 b 1.23 R⊕ Kepler-197 c 1.23 R⊕

Metric	Earth	Kepler-1987 b	Jupiter
Radius (R⊕)	1.00	1.23	11.21
Mass (M⊕)	1.00	2.04	317.83
Density (g/cm³)	5.51	6.02	1.33
Surface Gravity (g)	1.00	1.35	2.53
Insolation (S⊕)	1.00	233.38	0.037

Star Catalogue Identifiers

TIC

TIC 271958892

Gaia DR2

Gaia DR2 2078000289864478976

Gaia DR3

Gaia DR3 2078000289864478976

System

Kepler-1987

Percentile among Rocky Terrestrial cohort

Radius 1.230 R⊕ · percentile 94 / cohort 570

Mass 2.040 M⊕ · percentile 86 / cohort 570

Orbital period 2.35 d · percentile 26 / cohort 567

Distance 595.68 pc · percentile 73 / cohort 566

ESI 0.310 · percentile 42 / cohort 570

Orbit & Habitability

Orbital Dynamics

Period

2.346 days

Semi-major axis

0.0318 AU

Eccentricity

0.000

Inclination

89.81 °

Year Length

A year here lasts approximately 2.35 Earth days (0.6% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0318 AU.

Transit Fingerprint

Depth

0.032 %

Duration

1.680 h

Impact parameter b

0.035

Rp / R★

0.015717

Transit midpoint (BJD)

2,455,187.1119

Photometric dip

Transit produces a flux drop of 317 ppm lasting ≈ 1.68 h.

Extended Orbital Architecture

Planet / star radius ratio

0.015717

Semi-major axis / stellar radius

10.850

Impact parameter (b)

0.035

Transit mid-time (BJD)

2,455,187.1119

Angular separation (arcsec)

0.05340

Eq. Temperature

997K

(724 °C)

Insolation (S⊕)

233.38

Earth = 1.00

Earth Similarity (ESI)

0.310

0 = alien, 1 = Earth-identical

Inside the inner HZ boundary (too hot for liquid water) — the surface is too hot to retain surface water. Close-orbiting tidally-locked around a cool host.

Discovery Paper

Primary reference

Valizadegan et al. 2023

Instrument

Kepler CCD Array

Publication

2023-05

Observation locale

Space

Discovery cohort

Planets confirmed in 2023 at Kepler (12 shown).

Kepler-1126 c · Super-Earth Kepler-2000 c · Super-Earth Kepler-1052 c · Sub-Neptune Kepler-311 d · Sub-Neptune Kepler-1996 c · Sub-Neptune Kepler-1162 c · Super-Earth Kepler-1996 b · Sub-Neptune Kepler-1610 c · Sub-Neptune Kepler-1801 c · Sub-Neptune Kepler-1995 b · Neptune-like Kepler-1992 b · Rocky Terrestrial Kepler-1986 b · Super-Earth

Host System: Kepler-1987

Spectral Class

K-type orange

Effective Temperature

4,769 K — cooler than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

0.714 R☉

Stellar Mass

0.799 M☉

Metallicity [Fe/H]

0.12

Extended Stellar Properties

Surface gravity (log g)

4.622 dex

Stellar density

4.388 g/cm³

Metallicity ratio

[Fe/H]

Distance

595.68 parsec

Light-years 1,942.86 ly

V-band magnitude

15.48 mag

Voyager-speed travel 34,262,261 yr

Multi-band Host Photometry — 11 bands

Astrometric Data

Parallax

1.651 mas

Total Proper Motion

8.700 mas/yr

PM Right Ascension

-7.71 mas/yr

PM Declination

-4.04 mas/yr

Galactic Cartesian (pc)

x = 0.319 · y = -0.659 · z = 0.681

Equatorial (J2000)

RA 295.82547° · Dec 42.94337°

Galactic ℓ, b

76.612° · 9.467°

Ecliptic λ, β

313.709° · 62.518°

HTM-20 index

-1587338097