Key parameters at a glance

A radius of 1.07 Earth radii
A mass of 1.25 Earth masses
Surface gravity around 1.09 g
An orbital period of 37.424 days
Semi-major axis 0.1633 AU
Equilibrium temperature 269 K (-4 °C)
Distance from Earth 101.52 light-years
Earth Similarity Index 0.940
Travel time at Voyager 1 speed 1,790,322 years
Almost certainly tidally locked to its host star given the close orbit

Context from the literature

TOI-700 d is a dense, rocky, near-Earth-sized exoplanet orbiting within the habitable zone of the red dwarf TOI-700. It is located roughly 101.4 light-years (31.1 pc) away from Earth in the constellation of Dorado and is the outermost of four confirmed exoplanets around its star. The exoplanet is the first Earth-sized exoplanet in the habitable zone discovered by the Transiting Exoplanet Survey Satellite (TESS).

Excerpted from Wikipedia · full article

3 siblings around TOI-700

TOI-700 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-700 b	Rocky Terrestrial	0.91	0.70	9.977	417	2020
TOI-700 c	Sub-Neptune	2.60	7.27	16.051	356	2020
TOI-700 e	Rocky Terrestrial	0.95	0.82	27.810	273	2023
TOI-700 d this	Rocky Terrestrial	1.07	1.25	37.424	269	2020

TOI-700 d Planet Profile

Physical Specs

Radius

1.07 R⊕

Radius (Jupiter)

0.096 R♃

Mass

1.25 M⊕

Mass (Jupiter)

0.004 M♃

Density

5.56 g/cm³

Surface Gravity

1.09 g (Earth)

Classification

Planet Type

Rocky Terrestrial

ESI Score 0.940

HZ Position Habitable

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

#260of 570

top 45.4%

This planet

1.07R⊕

Rocky Terrestrial median

1.01R⊕

Nearest-size peers

HD 63433 d 1.07 R⊕ Kepler-1698 b 1.07 R⊕ K2-381 b 1.08 R⊕

Metric	Earth	TOI-700 d	Jupiter
Radius (R⊕)	1.00	1.07	11.21
Mass (M⊕)	1.00	1.25	317.83
Density (g/cm³)	5.51	5.56	1.33
Surface Gravity (g)	1.00	1.09	2.53
Insolation (S⊕)	1.00	0.85	0.037

Star Catalogue Identifiers

TIC

TIC 150428135

Gaia DR2

Gaia DR2 5284517766615492736

Gaia DR3

Gaia DR3 5284517766615850752

System

TOI-700

Percentile among Rocky Terrestrial cohort

Radius 1.073 R⊕ · percentile 54 / cohort 570

Mass 1.250 M⊕ · percentile 49 / cohort 570

Orbital period 37.42 d · percentile 98 / cohort 567

Distance 31.13 pc · percentile 14 / cohort 566

ESI 0.940 · percentile 93 / cohort 570

Orbit & Habitability

Orbital Dynamics

Period

37.424 days

Semi-major axis

0.1633 AU

Eccentricity

0.042

Inclination

89.80 °

Year Length

A year here lasts approximately 37.42 Earth days (10.2% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1633 AU.

Transit Fingerprint

Depth

0.061 %

Duration

3.314 h

Impact parameter b

0.290

Rp / R★

0.023390

Transit midpoint (BJD)

2,458,816.9952

Photometric dip

Transit produces a flux drop of 613 ppm lasting ≈ 3.31 h.

Extended Orbital Architecture

Planet / star radius ratio

0.023390

Semi-major axis / stellar radius

82.900

Impact parameter (b)

0.290

Transit mid-time (BJD)

2,458,816.9952

Long. of periastron (ω)

10.00°

Angular separation (arcsec)

5.25000

Eq. Temperature

269K

(-4 °C)

Insolation (S⊕)

0.85

Earth = 1.00

Earth Similarity (ESI)

0.940

0 = alien, 1 = Earth-identical

Within the conservative habitable zone — surface water would be frozen. Close-orbiting tidally-locked around a cool host.

Discovery Paper

Primary reference

Gilbert et al. 2020

Instrument

TESS CCD Array

Publication

2020-09

Observation locale

Space

Discovery cohort

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

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 TOI-540 b · Rocky Terrestrial LHS 1815 b · Rocky Terrestrial TOI-122 b · Sub-Neptune

Host System: TOI-700

Spectral Class

M-type red dwarf

Effective Temperature

3,459 K — cooler than the Sun (5,778 K)

Estimated Age

1.50 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

0.421 R☉

Stellar Mass

0.415 M☉

Metallicity [Fe/H]

-0.07

Extended Stellar Properties

Surface gravity (log g)

4.809 dex

Stellar density

7.860 g/cm³

Systemic radial velocity

-4.40 km/s

Rotation period

54.00 days

Metallicity ratio

[Fe/H]

Distance

31.13 parsec

Light-years 101.52 ly

V-band magnitude

13.15 mag

Voyager-speed travel 1,790,322 yr

Multi-band Host Photometry — 15 bands

Astrometric Data

Parallax

32.098 mas

Total Proper Motion

191.673 mas/yr

PM Right Ascension

-102.75 mas/yr

PM Declination

161.81 mas/yr

Galactic Cartesian (pc)

x = -0.051 · y = 0.410 · z = -0.911

Equatorial (J2000)

RA 97.09572° · Dec -65.57861°

Galactic ℓ, b

275.468° · -26.881°

Ecliptic λ, β

164.422° · -86.961°

HTM-20 index

-455754236

Wikipedia → Image: Wikimedia Commons · NASA's Goddard Space Flight Center · Public domain