Key parameters at a glance

A radius of 3.43 Earth radii
A mass of 5.40 Earth masses
Surface gravity around 0.46 g
An orbital period of 18.655 days
Semi-major axis 0.1320 AU
Equilibrium temperature 588 K (315 °C)
Distance from Earth 552.58 light-years
Earth Similarity Index 0.330
Travel time at Voyager 1 speed 9,744,748 years
Almost certainly tidally locked to its host star given the close orbit

3 siblings around TOI-1246

TOI-1246 d 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
TOI-1246 b	Sub-Neptune	3.01	8.10	4.307	955	2022
TOI-1246 c	Sub-Neptune	2.45	9.10	5.904	862	2022
TOI-1246 d this	Sub-Neptune	3.43	5.40	18.655	588	2022
TOI-1246 e	Sub-Neptune	3.51	14.50	37.925	464	2022

TOI-1246 d Planet Profile

Physical Specs

Radius

3.43 R⊕

Radius (Jupiter)

0.306 R♃

Mass

5.40 M⊕

Mass (Jupiter)

0.017 M♃

Density

0.73 g/cm³

Surface Gravity

0.46 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.330

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

#204of 1978

top 10.3%

This planet

3.43R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

HD 20003 b 3.43 R⊕ TOI-5789 e 3.43 R⊕ Kepler-182 c 3.43 R⊕

Metric	Earth	TOI-1246 d	Jupiter
Radius (R⊕)	1.00	3.43	11.21
Mass (M⊕)	1.00	5.40	317.83
Density (g/cm³)	5.51	0.73	1.33
Surface Gravity (g)	1.00	0.46	2.53
Insolation (S⊕)	1.00	28.00	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	5.400 M⊕	Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 230127302

Gaia DR2

Gaia DR2 1650110904522335744

Gaia DR3

Gaia DR3 1650110904522335744

System

TOI-1246

Percentile among Sub-Neptune cohort

Radius 3.431 R⊕ · percentile 90 / cohort 1978

Mass 5.400 M⊕ · percentile 14 / cohort 1978

Orbital period 18.65 d · percentile 59 / cohort 1946

Distance 169.42 pc · percentile 27 / cohort 1975

ESI 0.330 · percentile 35 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

18.655 days

Semi-major axis

0.1320 AU

Eccentricity

0.000

Inclination

89.50 °

Year Length

A year here lasts approximately 18.65 Earth days (5.1% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1320 AU.

Transit Fingerprint

Depth

0.150 %

Duration

3.948 h

Impact parameter b

0.425

Rp / R★

0.036375

Transit midpoint (BJD)

2,458,688.9750

Photometric dip

Transit produces a flux drop of 1,495 ppm lasting ≈ 3.95 h.

Extended Orbital Architecture

Planet / star radius ratio

0.036375

Semi-major axis / stellar radius

35.700

Impact parameter (b)

0.425

RV semi-amplitude (K)

1.410 m/s

Transit mid-time (BJD)

2,458,688.9750

Long. of periastron (ω)

90.00°

Angular separation (arcsec)

0.77900

Eq. Temperature

588K

(315 °C)

Insolation (S⊕)

28.00

Earth = 1.00

Earth Similarity (ESI)

0.330

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.

Transit timing variations

Gravitational interactions from neighbours have been detected.

Discovery Paper

Primary reference

Turtelboom et al. 2022

Instrument

TESS CCD Array

Publication

2022-04

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 LP 890-9 b · Super-Earth 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

Host System: TOI-1246

Spectral Class

K-type orange

Effective Temperature

5,213 K — cooler than the Sun (5,778 K)

Estimated Age

6.30 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

0.865 R☉

Stellar Mass

0.889 M☉

Metallicity [Fe/H]

0.17

Extended Stellar Properties

Surface gravity (log g)

4.510 dex

Stellar density

1.918 g/cm³

Rotational v·sin i

1.00 km/s

Rotation period

38.00 days

Metallicity ratio

[Fe/H]

Distance

169.42 parsec

Light-years 552.58 ly

V-band magnitude

11.63 mag

Voyager-speed travel 9,744,748 yr

Multi-band Host Photometry — 11 bands

Astrometric Data

Parallax

5.874 mas

Total Proper Motion

94.966 mas/yr

PM Right Ascension

-48.02 mas/yr

PM Declination

81.93 mas/yr

Galactic Cartesian (pc)

x = -0.108 · y = -0.317 · z = 0.942

Equatorial (J2000)

RA 251.11587° · Dec 70.42999°

Galactic ℓ, b

102.341° · 35.908°

Ecliptic λ, β

142.219° · 82.117°

HTM-20 index

-1212117917

Similar Worlds

Kepler-357 d

Sub-Neptune · K-type orange

Radius 3.43 R⊕ · 2,245.8 ly

TOI-5789 e

Sub-Neptune · K-type orange

Radius 3.43 R⊕ · 66.7 ly

Kepler-712 b

Sub-Neptune · K-type orange

Radius 3.41 R⊕ · 2,845.7 ly

HD 69830 c

Sub-Neptune · K-type orange

Radius 3.46 R⊕ · 41.0 ly

TOI-1853 b

Sub-Neptune · K-type orange

Radius 3.46 R⊕ · 538.5 ly

K2-105 b

Sub-Neptune · K-type orange

Radius 3.40 R⊕ · 645.8 ly

Explore Related Categories

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