Key parameters at a glance

A radius of 1.32 Earth radii
A mass of 13.20 Earth masses
Surface gravity around 7.58 g
An orbital period of 2.730 days
Semi-major axis 0.0188 AU
Equilibrium temperature 396 K (123 °C)
Distance from Earth 105.77 light-years
Earth Similarity Index 0.595
Travel time at Voyager 1 speed 1,865,285 years
Almost certainly tidally locked to its host star given the close orbit

Context from the literature

LP 890-9, also known as SPECULOOS-2 or TOI-4306, is a high proper motion red dwarf star located 105 light-years (32 pc) away from the Solar System in the constellation of Eridanus. The star has 12% the mass and 15% the radius of the Sun, and a temperature of 2,871 K. It is extremely faint and, with an apparent magnitude of 18, is the faintest star with exoplanets discovered by the Transiting Exoplanet Survey Satellite.

Excerpted from Wikipedia · full article

1 sibling around LP 890-9

LP 890-9 b shares its host star with 1 other confirmed planet. Side-by-side measurements below.

Planet	Type	Radius (R⊕)	Mass (M⊕)	Period (d)	Eq. T (K)	Year
LP 890-9 b this	Super-Earth	1.32	13.20	2.730	396	2022
LP 890-9 c	Super-Earth	1.37	25.30	8.457	272	2022

LP 890-9 b Planet Profile

Physical Specs

Radius

1.32 R⊕

Radius (Jupiter)

0.118 R♃

Mass

13.20 M⊕

Mass (Jupiter)

0.042 M♃

Density

— g/cm³

Surface Gravity

7.58 g (Earth)

Classification

Planet Type

Super-Earth

ESI Score 0.595

HZ Position Inner

Controversial No

Discovery

Year 2022

Method Transit

Facility Transiting Exoplanet Survey Satellite (TESS)

Telescope 0.1 m TESS Telescope

Size rank in cohort

Rank by radius

#1049of 1176

top 89.1%

This planet

1.32R⊕

Super-Earth median

1.60R⊕

Nearest-size peers

Kepler-1506 b 1.32 R⊕ Kepler-383 b 1.32 R⊕ Kepler-157 b 1.32 R⊕

Metric	Earth	LP 890-9 b	Jupiter
Radius (R⊕)	1.00	1.32	11.21
Mass (M⊕)	1.00	13.20	317.83
Density (g/cm³)	5.51	—	1.33
Surface Gravity (g)	1.00	7.58	2.53
Insolation (S⊕)	1.00	4.09	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	13.200 M⊕	Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 44898913

Gaia DR2

Gaia DR2 4886243456388510720

Gaia DR3

Gaia DR3 4886243456388510720

System

LP 890-9

Percentile among Super-Earth cohort

Radius 1.320 R⊕ · percentile 9 / cohort 1176

Mass 13.200 M⊕ · percentile 97 / cohort 1176

Orbital period 2.73 d · percentile 19 / cohort 1164

Distance 32.43 pc · percentile 7 / cohort 1171

ESI 0.595 · percentile 80 / cohort 1176

Orbit & Habitability

Orbital Dynamics

Period

2.730 days

Semi-major axis

0.0188 AU

Eccentricity

—

Inclination

89.67 °

Year Length

A year here lasts approximately 2.73 Earth days (0.7% of a terrestrial year) at a mean orbital distance of 0.0187 AU.

Transit Fingerprint

Depth

0.624 %

Duration

0.846 h

Impact parameter b

0.150

Transit midpoint (BJD)

2,459,447.8264

Photometric dip

Transit produces a flux drop of 6,238 ppm lasting ≈ 0.85 h.

Extended Orbital Architecture

Semi-major axis / stellar radius

26.320

Impact parameter (b)

0.150

RV semi-amplitude (K)

25.100 m/s

Transit mid-time (BJD)

2,459,447.8264

Angular separation (arcsec)

0.57800

Eq. Temperature

396K

(123 °C)

Insolation (S⊕)

4.09

Earth = 1.00

Earth Similarity (ESI)

0.595

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

Delrez et al. 2022

Instrument

TESS CCD Array

Publication

2022-09

Observation locale

Space

Discovery cohort

Planets confirmed in 2022 at Transiting Exoplanet Survey Satellite (TESS) (12 shown).

TOI-1452 b · Super-Earth TOI-712 d · Sub-Neptune TOI-1468 c · Sub-Neptune TOI-2136 b · Sub-Neptune LTT 1445 A c · Rocky Terrestrial TOI-712 c · Sub-Neptune TOI-2081 b · Sub-Neptune GJ 3929 b · Rocky Terrestrial HD 260655 c · Super-Earth HD 73583 c · Sub-Neptune TOI-1759 b · Sub-Neptune TOI-1246 e · Sub-Neptune

Host System: LP 890-9

Spectral Class

M-type red dwarf

Effective Temperature

2,850 K — cooler than the Sun (5,778 K)

Estimated Age

7.20 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

0.156 R☉

Stellar Mass

0.118 M☉

Metallicity [Fe/H]

-0.03

Extended Stellar Properties

Surface gravity (log g)

5.126 dex

Stellar density

44.200 g/cm³

Systemic radial velocity

27.94 km/s

Metallicity ratio

[Fe/H]

Distance

32.43 parsec

Light-years 105.77 ly

V-band magnitude

18.00 mag

Voyager-speed travel 1,865,285 yr

Multi-band Host Photometry — 6 bands

Astrometric Data

Parallax

30.807 mas

Total Proper Motion

332.902 mas/yr

PM Right Ascension

218.53 mas/yr

PM Declination

-251.13 mas/yr

Galactic Cartesian (pc)

x = 0.384 · y = 0.792 · z = -0.474

Equatorial (J2000)

RA 64.13091° · Dec -28.31579°

Galactic ℓ, b

226.914° · -44.948°

Ecliptic λ, β

54.475° · -48.615°

HTM-20 index

-217062951

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