Key parameters at a glance

A radius of 1.28 Earth radii
A mass of 1.48 Earth masses
Surface gravity around 0.90 g
An orbital period of 3.360 days
Semi-major axis 0.0320 AU
Equilibrium temperature 600 K (327 °C)
Distance from Earth 73.32 light-years
Earth Similarity Index 0.507
Travel time at Voyager 1 speed 1,292,956 years
Almost certainly tidally locked to its host star given the close orbit

Context from the literature

TOI-270, also known as L 231-32, is a red dwarf star 73.3 light-years away in the constellation Pictor. It has about 39% the mass and 38% the radius of the Sun, and a temperature of about 3,506 K. TOI-270 hosts a system of three known exoplanets.

Excerpted from Wikipedia · full article

2 siblings around TOI-270

TOI-270 b 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-270 b this	Super-Earth	1.28	1.48	3.360	600	2019
TOI-270 c	Sub-Neptune	2.33	6.20	5.661	489	2019
TOI-270 d	Sub-Neptune	2.00	4.20	11.382	383	2019

TOI-270 b Planet Profile

Physical Specs

Radius

1.28 R⊕

Radius (Jupiter)

0.114 R♃

Mass

1.48 M⊕

Mass (Jupiter)

0.005 M♃

Density

3.89 g/cm³

Surface Gravity

0.90 g (Earth)

Classification

Planet Type

Super-Earth

ESI Score 0.507

HZ Position Inner

Controversial No

Discovery

Year 2019

Method Transit

Facility Transiting Exoplanet Survey Satellite (TESS)

Telescope 0.1 m TESS Telescope

Size rank in cohort

Rank by radius

#1117of 1176

top 94.9%

This planet

1.28R⊕

Super-Earth median

1.60R⊕

Nearest-size peers

Kepler-1420 b 1.28 R⊕ TOI-431 b 1.28 R⊕ Kepler-776 b 1.28 R⊕

Metric	Earth	TOI-270 b	Jupiter
Radius (R⊕)	1.00	1.28	11.21
Mass (M⊕)	1.00	1.48	317.83
Density (g/cm³)	5.51	3.89	1.33
Surface Gravity (g)	1.00	0.90	2.53
Insolation (S⊕)	1.00	131.79	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	1.480 M⊕	Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 259377017

Gaia DR2

Gaia DR2 4781196115469953024

Gaia DR3

Gaia DR3 4781196115469953024

System

TOI-270

Percentile among Super-Earth cohort

Radius 1.280 R⊕ · percentile 4 / cohort 1176

Mass 1.480 M⊕ · percentile 0 / cohort 1176

Orbital period 3.36 d · percentile 25 / cohort 1164

Distance 22.48 pc · percentile 4 / cohort 1171

ESI 0.507 · percentile 73 / cohort 1176

Orbit & Habitability

Orbital Dynamics

Period

3.360 days

Semi-major axis

0.0320 AU

Eccentricity

0.017

Inclination

89.39 °

Year Length

A year here lasts approximately 3.36 Earth days (0.9% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0320 AU.

Transit Fingerprint

Depth

0.098 %

Duration

1.294 h

Impact parameter b

0.480

Rp / R★

0.030700

Transit midpoint (BJD)

2,458,461.0146

Photometric dip

Transit produces a flux drop of 977 ppm lasting ≈ 1.29 h.

Extended Orbital Architecture

Planet / star radius ratio

0.030700

Semi-major axis / stellar radius

17.108

Impact parameter (b)

0.480

RV semi-amplitude (K)

1.270 m/s

Transit mid-time (BJD)

2,458,461.0146

Long. of periastron (ω)

0.00°

Angular separation (arcsec)

1.42000

Eq. Temperature

600K

(327 °C)

Insolation (S⊕)

131.79

Earth = 1.00

Earth Similarity (ESI)

0.507

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

G Uuml Nther et al. 2019

Instrument

TESS CCD Array

Publication

2019-07

Observation locale

Space

Discovery cohort

Planets confirmed in 2019 at Transiting Exoplanet Survey Satellite (TESS) (12 shown).

LP 791-18 c · Sub-Neptune LTT 1445 A b · Super-Earth TOI-270 d · Sub-Neptune L 98-59 d · Super-Earth GJ 357 b · Rocky Terrestrial GJ 143 b · Sub-Neptune HD 23472 c · Super-Earth L 98-59 c · Super-Earth LP 791-18 b · Rocky Terrestrial TOI-270 c · Sub-Neptune HD 23472 b · Sub-Neptune L 98-59 b · Rocky Terrestrial

Host System: TOI-270

Spectral Class

M-type red dwarf

Effective Temperature

3,506 K — cooler than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

0.380 R☉

Stellar Mass

0.386 M☉

Metallicity [Fe/H]

-0.17

Extended Stellar Properties

Surface gravity (log g)

4.872 dex

Stellar density

10.630 g/cm³

Metallicity ratio

[Fe/H]

Distance

22.48 parsec

Light-years 73.32 ly

V-band magnitude

12.60 mag

Voyager-speed travel 1,292,956 yr

Multi-band Host Photometry — 14 bands

Astrometric Data

Parallax

44.457 mas

Total Proper Motion

282.219 mas/yr

PM Right Ascension

82.94 mas/yr

PM Declination

-269.76 mas/yr

Galactic Cartesian (pc)

x = 0.227 · y = 0.573 · z = -0.788

Equatorial (J2000)

RA 68.41608° · Dec -51.95739°

Galactic ℓ, b

259.774° · -42.014°

Ecliptic λ, β

43.142° · -71.898°

HTM-20 index

224185686

Wikipedia →