Key parameters at a glance

A radius of 2.76 Earth radii
A mass of 13.20 Earth masses
Surface gravity around 1.73 g
An orbital period of 7.493 days
Semi-major axis 0.0657 AU
Equilibrium temperature 651 K (378 °C)
Distance from Earth 240.04 light-years
Earth Similarity Index 0.397
Travel time at Voyager 1 speed 4,233,164 years
Almost certainly tidally locked to its host star given the close orbit

2 siblings around TOI-1260

TOI-1260 c shares its host star with 2 other confirmed planets. Side-by-side measurements below.

Planet	Type	Radius (R⊕)	Mass (M⊕)	Period (d)	Eq. T (K)	Year
TOI-1260 b	Sub-Neptune	2.41	8.56	3.127	871	2021
TOI-1260 c this	Sub-Neptune	2.76	13.20	7.493	651	2021
TOI-1260 d	Sub-Neptune	3.12	11.84	16.608	499	2022

TOI-1260 c Planet Profile

Physical Specs

Radius

2.76 R⊕

Radius (Jupiter)

0.246 R♃

Mass

13.20 M⊕

Mass (Jupiter)

0.042 M♃

Density

3.45 g/cm³

Surface Gravity

1.73 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.397

HZ Position Inner

Controversial No

Discovery

Year 2021

Method Transit

Facility Transiting Exoplanet Survey Satellite (TESS)

Telescope 0.1 m TESS Telescope

Size rank in cohort

Rank by radius

#794of 1978

top 40.1%

This planet

2.76R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-819 b 2.76 R⊕ Kepler-172 e 2.76 R⊕ Kepler-1458 b 2.76 R⊕

Metric	Earth	TOI-1260 c	Jupiter
Radius (R⊕)	1.00	2.76	11.21
Mass (M⊕)	1.00	13.20	317.83
Density (g/cm³)	5.51	3.45	1.33
Surface Gravity (g)	1.00	1.73	2.53
Insolation (S⊕)	1.00	29.81	0.037

Alternative Mass Estimates

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

Star Catalogue Identifiers

TIC

TIC 355867695

Gaia DR2

Gaia DR2 1053809778428567680

Gaia DR3

Gaia DR3 1053809778428567680

System

TOI-1260

Percentile among Sub-Neptune cohort

Radius 2.760 R⊕ · percentile 60 / cohort 1978

Mass 13.200 M⊕ · percentile 88 / cohort 1978

Orbital period 7.49 d · percentile 24 / cohort 1946

Distance 73.60 pc · percentile 16 / cohort 1975

ESI 0.397 · percentile 51 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

7.493 days

Semi-major axis

0.0657 AU

Eccentricity

0.000

Inclination

87.97 °

Year Length

A year here lasts approximately 7.49 Earth days (2.1% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0657 AU.

Transit Fingerprint

Depth

0.142 %

Duration

1.970 h

Impact parameter b

0.750

Rp / R★

0.037700

Transit midpoint (BJD)

2,459,068.2705

Photometric dip

Transit produces a flux drop of 1,421 ppm lasting ≈ 1.97 h.

Extended Orbital Architecture

Planet / star radius ratio

0.037700

Semi-major axis / stellar radius

20.990

Impact parameter (b)

0.750

RV semi-amplitude (K)

5.670 m/s

Transit mid-time (BJD)

2,459,068.2705

Long. of periastron (ω)

0.00°

Angular separation (arcsec)

0.89300

Eq. Temperature

651K

(378 °C)

Insolation (S⊕)

29.81

Earth = 1.00

Earth Similarity (ESI)

0.397

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

Georgieva et al. 2021

Instrument

TESS CCD Array

Publication

2021-08

Observation locale

Space

Discovery cohort

Planets confirmed in 2021 at Transiting Exoplanet Survey Satellite (TESS) (12 shown).

TOI-2257 b · Sub-Neptune TOI-2285 b · Super-Earth TOI-1231 b · Sub-Neptune AU Mic c · Sub-Neptune LHS 1678 c · Rocky Terrestrial LHS 1478 b · Rocky Terrestrial TOI-2406 b · Sub-Neptune HD 207897 b · Sub-Neptune TOI-269 b · Sub-Neptune TIC 172900988 b · Gas Giant TOI-178 g · Sub-Neptune TOI-2076 d · Sub-Neptune

Host System: TOI-1260

Spectral Class

K-type orange

Effective Temperature

4,227 K — cooler than the Sun (5,778 K)

Estimated Age

6.70 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

0.672 R☉

Stellar Mass

0.679 M☉

Metallicity [Fe/H]

-0.10

Extended Stellar Properties

Surface gravity (log g)

4.570 dex

Stellar density

3.430 g/cm³

Rotational v·sin i

1.50 km/s

Rotation period

30.63 days

Activity index (log R'HK)

-4.860

Metallicity ratio

[Fe/H]

Distance

73.60 parsec

Light-years 240.04 ly

V-band magnitude

11.92 mag

Voyager-speed travel 4,233,164 yr

Multi-band Host Photometry — 11 bands

Astrometric Data

Parallax

13.559 mas

Total Proper Motion

195.190 mas/yr

PM Right Ascension

-177.24 mas/yr

PM Declination

-81.77 mas/yr

Galactic Cartesian (pc)

x = -0.377 · y = 0.159 · z = 0.913

Equatorial (J2000)

RA 157.14407° · Dec 65.85420°

Galactic ℓ, b

142.804° · 45.372°

Ecliptic λ, β

126.532° · 50.715°

HTM-20 index

-454174731

Similar Worlds

K2-123 b

Sub-Neptune · K-type orange

Radius 2.76 R⊕ · 526.9 ly

Kepler-305 d

Sub-Neptune · K-type orange

Radius 2.76 R⊕ · 2,832.6 ly

TOI-125 c

Sub-Neptune · K-type orange

Radius 2.76 R⊕ · 362.2 ly

TOI-969 b

Sub-Neptune · K-type orange

Radius 2.77 R⊕ · 252.0 ly

TOI-444 b

Sub-Neptune · K-type orange

Radius 2.77 R⊕ · 187.2 ly

Kepler-304 d

Sub-Neptune · K-type orange

Radius 2.75 R⊕ · 1,417.7 ly

Explore Related Categories

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