Key parameters at a glance

A radius of 1.12 Earth radii
A mass of 1.46 Earth masses
Surface gravity around 1.16 g
An orbital period of 4.425 days
Semi-major axis 0.0417 AU
Equilibrium temperature 544 K (271 °C)
Distance from Earth 10.72 light-years
Earth Similarity Index 0.584
Travel time at Voyager 1 speed 189,048 years
Almost certainly tidally locked to its host star given the close orbit

3 siblings around GJ 887

GJ 887 e 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
GJ 887 e this	Rocky Terrestrial	1.12	1.46	4.425	544	2026
GJ 887 b	Super-Earth	1.80	3.90	9.262	426	2020
GJ 887 c	Sub-Neptune	2.43	6.50	21.784	320	2020
GJ 887 d	Sub-Neptune	2.34	6.10	50.770	241	2026

GJ 887 e Planet Profile

Physical Specs

Radius

1.12 R⊕

Radius (Jupiter)

0.100 R♃

Mass

1.46 M⊕

Mass (Jupiter)

0.005 M♃

Density

5.71 g/cm³

Surface Gravity

1.16 g (Earth)

Classification

Planet Type

Rocky Terrestrial

ESI Score 0.584

HZ Position Inner

Controversial No

Discovery

Year 2026

Method Radial Velocity

Facility Multiple Observatories

Telescope Multiple Telescopes

Size rank in cohort

Rank by radius

#193of 570

top 33.7%

This planet

1.12R⊕

Rocky Terrestrial median

1.01R⊕

Nearest-size peers

Kepler-381 c 1.12 R⊕ Kepler-1082 b 1.12 R⊕ Kepler-1288 b 1.12 R⊕

Metric	Earth	GJ 887 e	Jupiter
Radius (R⊕)	1.00	1.12	11.21
Mass (M⊕)	1.00	1.46	317.83
Density (g/cm³)	5.51	5.71	1.33
Surface Gravity (g)	1.00	1.16	2.53
Insolation (S⊕)	1.00	20.90	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Minimum mass (M sin i)	1.460 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HD 217987

HIP

HIP 114046

TIC

TIC 155315739

Gaia DR2

Gaia DR2 6553614253923452800

Gaia DR3

Gaia DR3 6553614253923452800

System

GJ 887

Percentile among Rocky Terrestrial cohort

Radius 1.120 R⊕ · percentile 64 / cohort 570

Mass 1.460 M⊕ · percentile 59 / cohort 570

Orbital period 4.42 d · percentile 49 / cohort 567

Distance 3.29 pc · percentile 1 / cohort 566

ESI 0.584 · percentile 76 / cohort 570

Orbit & Habitability

Orbital Dynamics

Period

4.425 days

Semi-major axis

0.0417 AU

Eccentricity

—

Inclination

— °

Year Length

A year here lasts approximately 4.42 Earth days (1.2% of a terrestrial year) at a mean orbital distance of 0.0417 AU.

Eq. Temperature

544K

(271 °C)

Insolation (S⊕)

20.90

Earth = 1.00

Earth Similarity (ESI)

0.584

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

Hartogh et al. 2026

Instrument

Multiple Instruments

Publication

2026-02

Observation locale

Ground

Discovery cohort

Planets confirmed in 2026 at Multiple Observatories (12 shown).

DMPP-6 b · Sub-Neptune TOI-4336 A c · Super-Earth GJ 887 d · Sub-Neptune HD 176986 d · Sub-Neptune DMPP-6 c · Sub-Neptune DMPP-9 b · Sub-Neptune TOI-5789 d · Super-Earth TOI-5789 e · Sub-Neptune HD 85426 c · Sub-Neptune DMPP-2 c · Neptune-like DMPP-7 b · Neptune-like TOI-375 d · Gas Giant

Host System: GJ 887

Spectral Class

M-type red dwarf

Effective Temperature

3,688 K — cooler than the Sun (5,778 K)

Estimated Age

2.90 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

0.468 R☉

Stellar Mass

0.495 M☉

Metallicity [Fe/H]

-0.06

Extended Stellar Properties

Surface gravity (log g)

4.156 dex

Stellar density

6.056 g/cm³

Systemic radial velocity

8.17 km/s

Rotational v·sin i

2.50 km/s

Rotation period

38.70 days

Metallicity ratio

[Fe/H]

Distance

3.29 parsec

Light-years 10.72 ly

V-band magnitude

7.56 mag

Voyager-speed travel 189,048 yr

Multi-band Host Photometry — 8 bands

Astrometric Data

Parallax

304.219 mas

Total Proper Motion

6,895.546 mas/yr

PM Right Ascension

6,765.99 mas/yr

PM Declination

1,330.39 mas/yr

Galactic Cartesian (pc)

x = 0.788 · y = -0.189 · z = -0.586

Equatorial (J2000)

RA 346.50276° · Dec -35.84735°

Galactic ℓ, b

5.097° · -65.987°

Ecliptic λ, β

332.713° · -27.519°

HTM-20 index

215838338