Key parameters at a glance

A radius of 2.62 Earth radii
A mass of 23.50 Earth masses
Surface gravity around 3.42 g
An orbital period of 34.976 days
Semi-major axis 0.1930 AU
Equilibrium temperature 469 K (196 °C)
Distance from Earth 194.75 light-years
Earth Similarity Index 0.535
Travel time at Voyager 1 speed 3,434,474 years
Almost certainly tidally locked to its host star given the close orbit

1 sibling around TOI-815

TOI-815 c 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
TOI-815 b	Sub-Neptune	2.94	7.60	11.197	686	2024
TOI-815 c this	Sub-Neptune	2.62	23.50	34.976	469	2024

TOI-815 c Planet Profile

Physical Specs

Radius

2.62 R⊕

Radius (Jupiter)

0.234 R♃

Mass

23.50 M⊕

Mass (Jupiter)

0.074 M♃

Density

7.20 g/cm³

Surface Gravity

3.42 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.535

HZ Position Inner

Controversial No

Discovery

Year 2024

Method Transit

Facility Transiting Exoplanet Survey Satellite (TESS)

Telescope 0.1 m TESS Telescope

Size rank in cohort

Rank by radius

#989of 1978

top 49.9%

This planet

2.62R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-977 b 2.62 R⊕ K2-337 b 2.62 R⊕ Kepler-450 c 2.62 R⊕

Metric	Earth	TOI-815 c	Jupiter
Radius (R⊕)	1.00	2.62	11.21
Mass (M⊕)	1.00	23.50	317.83
Density (g/cm³)	5.51	7.20	1.33
Surface Gravity (g)	1.00	3.42	2.53
Insolation (S⊕)	1.00	8.03	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	23.500 M⊕	Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 102840239

Gaia DR2

Gaia DR2 5415648821879172096

Gaia DR3

Gaia DR3 5415648821879172096

System

TOI-815

Percentile among Sub-Neptune cohort

Radius 2.620 R⊕ · percentile 50 / cohort 1978

Mass 23.500 M⊕ · percentile 96 / cohort 1978

Orbital period 34.98 d · percentile 77 / cohort 1946

Distance 59.71 pc · percentile 13 / cohort 1975

ESI 0.535 · percentile 75 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

34.976 days

Semi-major axis

0.1930 AU

Eccentricity

0.220

Inclination

89.11 °

Year Length

A year here lasts approximately 34.98 Earth days (9.6% of a terrestrial year) on a mildly elliptical path at a mean orbital distance of 0.1930 AU.

Transit Fingerprint

Depth

0.100 %

Duration

2.970 h

Impact parameter b

0.839

Rp / R★

0.031200

Transit midpoint (BJD)

2,459,288.6331

Photometric dip

Transit produces a flux drop of 1,004 ppm lasting ≈ 2.97 h.

Extended Orbital Architecture

Planet / star radius ratio

0.031200

Semi-major axis / stellar radius

53.900

Impact parameter (b)

0.839

RV semi-amplitude (K)

5.500 m/s

Transit mid-time (BJD)

2,459,288.6331

Angular separation (arcsec)

3.23000

Eq. Temperature

469K

(196 °C)

Insolation (S⊕)

8.03

Earth = 1.00

Earth Similarity (ESI)

0.535

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.

Detection Signatures

Transit photometry

A transit dip has been observed from at least one telescope.

Radial velocity

Stellar wobble has been measured spectroscopically.

Discovery Paper

Primary reference

Psaridi et al. 2024

Instrument

TESS CCD Array

Publication

2024-05

Observation locale

Space

Discovery cohort

Planets confirmed in 2024 at Transiting Exoplanet Survey Satellite (TESS) (12 shown).

Gliese 12 b · Rocky Terrestrial TOI-6002 b · Super-Earth TOI-5713 b · Super-Earth TOI-4336 A b · Sub-Neptune TOI-406.01 · Sub-Neptune TOI-1224 c · Sub-Neptune LHS 1678 d · Rocky Terrestrial TOI-2088 b · Sub-Neptune TOI-2120 b · Sub-Neptune TOI-1806.01 · Sub-Neptune TOI-4633 c · Sub-Neptune TOI-260 b · Super-Earth

Host System: TOI-815

Spectral Class

K-type orange

Effective Temperature

4,869 K — cooler than the Sun (5,778 K)

Estimated Age

0.20 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

0.770 R☉

Stellar Mass

0.776 M☉

Metallicity [Fe/H]

-0.09

Extended Stellar Properties

Surface gravity (log g)

4.510 dex

Stellar density

2.431 g/cm³

Systemic radial velocity

-2.97 km/s

Rotational v·sin i

1.00 km/s

Rotation period

15.30 days

Metallicity ratio

[Fe/H]

Distance

59.71 parsec

Light-years 194.75 ly

V-band magnitude

10.22 mag

Voyager-speed travel 3,434,474 yr

Multi-band Host Photometry — 11 bands

Astrometric Data

Parallax

16.718 mas

Total Proper Motion

11.408 mas/yr

PM Right Ascension

8.93 mas/yr

PM Declination

7.10 mas/yr

Galactic Cartesian (pc)

x = -0.658 · y = 0.295 · z = -0.693

Equatorial (J2000)

RA 155.87194° · Dec -43.83492°

Galactic ℓ, b

276.658° · 11.361°

Ecliptic λ, β

180.428° · -48.827°

HTM-20 index

-1805516204

Similar Worlds

K2-54 b

Sub-Neptune · K-type orange

Radius 2.61 R⊕ · 570.6 ly

Kepler-257 b

Sub-Neptune · K-type orange

Radius 2.61 R⊕ · 2,544.9 ly

GJ 414 A b

Sub-Neptune · K-type orange

Radius 2.63 R⊕ · 38.8 ly

GJ 143 b

Sub-Neptune · K-type orange

Radius 2.61 R⊕ · 53.2 ly

Kepler-242 b

Sub-Neptune · K-type orange

Radius 2.61 R⊕ · 1,957.7 ly

Kepler-970 b

Sub-Neptune · K-type orange

Radius 2.61 R⊕ · 1,081.4 ly

Explore Related Categories

Sub-Neptune Planets Transit Discoveries Transiting Exoplanet Survey Satellite (TESS) Mission K-type orange Hosts