Key parameters at a glance

A radius of 0.90 Earth radii
A mass of 0.67 Earth masses
Surface gravity around 0.83 g
An orbital period of 1.239 days
Semi-major axis 0.0122 AU
Equilibrium temperature 611 K (338 °C)
Distance from Earth 45.67 light-years
Earth Similarity Index 0.520
Travel time at Voyager 1 speed 805,373 years
Almost certainly tidally locked to its host star given the close orbit

TOI-540 b Planet Profile

Physical Specs

Radius

0.90 R⊕

Radius (Jupiter)

0.081 R♃

Mass

0.67 M⊕

Mass (Jupiter)

0.002 M♃

Density

5.03 g/cm³

Surface Gravity

0.83 g (Earth)

Classification

Planet Type

Rocky Terrestrial

ESI Score 0.520

HZ Position Inner

Controversial No

Discovery

Year 2020

Method Transit

Facility Transiting Exoplanet Survey Satellite (TESS)

Telescope 0.1 m TESS Telescope

Size rank in cohort

Rank by radius

#414of 570

top 72.5%

This planet

0.90R⊕

Rocky Terrestrial median

1.01R⊕

Nearest-size peers

Kepler-1759 b 0.90 R⊕ Kepler-1398 b 0.90 R⊕ Kepler-1547 b 0.90 R⊕

Metric	Earth	TOI-540 b	Jupiter
Radius (R⊕)	1.00	0.90	11.21
Mass (M⊕)	1.00	0.67	317.83
Density (g/cm³)	5.51	5.03	1.33
Surface Gravity (g)	1.00	0.83	2.53
Insolation (S⊕)	1.00	23.40	0.037

Star Catalogue Identifiers

TIC

TIC 200322593

Gaia DR2

Gaia DR2 4785886941312921344

Gaia DR3

Gaia DR3 4785886941312921344

System

TOI-540

Percentile among Rocky Terrestrial cohort

Radius 0.903 R⊕ · percentile 27 / cohort 570

Mass 0.674 M⊕ · percentile 23 / cohort 570

Orbital period 1.24 d · percentile 14 / cohort 567

Distance 14.00 pc · percentile 8 / cohort 566

ESI 0.520 · percentile 72 / cohort 570

Orbit & Habitability

Orbital Dynamics

Period

1.239 days

Semi-major axis

0.0122 AU

Eccentricity

0.000

Inclination

86.80 °

Year Length

A year here lasts approximately 1.24 Earth days (0.3% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0122 AU.

Transit Fingerprint

Depth

0.232 %

Duration

0.489 h

Impact parameter b

0.772

Rp / R★

0.043600

Transit midpoint (BJD)

2,458,411.8260

Photometric dip

Transit produces a flux drop of 2,319 ppm lasting ≈ 0.49 h.

Extended Orbital Architecture

Planet / star radius ratio

0.043600

Semi-major axis / stellar radius

13.900

Impact parameter (b)

0.772

Transit mid-time (BJD)

2,458,411.8260

Angular separation (arcsec)

0.87300

Eq. Temperature

611K

(338 °C)

Insolation (S⊕)

23.40

Earth = 1.00

Earth Similarity (ESI)

0.520

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

Ment et al. 2021

Instrument

TESS CCD Array

Publication

2021-01

Observation locale

Space

Discovery cohort

Planets confirmed in 2020 at Transiting Exoplanet Survey Satellite (TESS) (12 shown).

TOI-700 d · Rocky Terrestrial TOI-237 b · Super-Earth TOI-700 b · Rocky Terrestrial TOI-1266 c · Super-Earth LTT 3780 c · Sub-Neptune TOI-700 c · Sub-Neptune TOI-776 c · Sub-Neptune TOI-942 c · Neptune-like TOI-776 b · Super-Earth TOI-1266 b · Sub-Neptune LHS 1815 b · Rocky Terrestrial TOI-122 b · Sub-Neptune

Host System: TOI-540

Spectral Class

M-type red dwarf

Effective Temperature

3,216 K — cooler than the Sun (5,778 K)

Estimated Age

1.10 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

0.190 R☉

Stellar Mass

0.159 M☉

Metallicity [Fe/H]

—

Extended Stellar Properties

Surface gravity (log g)

4.438 dex

Stellar density

30.586 g/cm³

Rotational v·sin i

13.50 km/s

Rotation period

0.73 days

Distance

14.00 parsec

Light-years 45.67 ly

V-band magnitude

14.82 mag

Voyager-speed travel 805,373 yr

Multi-band Host Photometry — 12 bands

Astrometric Data

Parallax

71.389 mas

Total Proper Motion

70.683 mas/yr

PM Right Ascension

-66.09 mas/yr

PM Declination

25.08 mas/yr

Galactic Cartesian (pc)

x = 0.159 · y = 0.651 · z = -0.742

Equatorial (J2000)

RA 76.30969° · Dec -47.93754°

Galactic ℓ, b

254.108° · -37.231°

Ecliptic λ, β

62.286° · -70.063°

HTM-20 index

1447300755