Key parameters at a glance

A radius of 1.33 Earth radii
A mass of 2.46 Earth masses
Surface gravity around 1.40 g
An orbital period of 0.768 days
Semi-major axis 0.0120 AU
Equilibrium temperature 903 K (630 °C)
Distance from Earth 71.69 light-years
Earth Similarity Index 0.343
Travel time at Voyager 1 speed 1,264,318 years
Almost certainly tidally locked to its host star given the close orbit

1 sibling around LTT 3780

LTT 3780 b shares its host star with 1 other confirmed planet. Side-by-side measurements below.

Planet	Type	Radius (R⊕)	Mass (M⊕)	Period (d)	Eq. T (K)	Year
LTT 3780 b this	Super-Earth	1.33	2.46	0.768	903	2020
LTT 3780 c	Sub-Neptune	2.39	8.04	12.252	359	2020

LTT 3780 b Planet Profile

Physical Specs

Radius

1.33 R⊕

Radius (Jupiter)

0.118 R♃

Mass

2.46 M⊕

Mass (Jupiter)

0.008 M♃

Density

5.80 g/cm³

Surface Gravity

1.40 g (Earth)

Classification

Planet Type

Super-Earth

ESI Score 0.343

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

#1048of 1176

top 89.0%

This planet

1.33R⊕

Super-Earth median

1.60R⊕

Nearest-size peers

Kepler-1671 b 1.33 R⊕ Kepler-1888 b 1.33 R⊕ L 98-59 c 1.33 R⊕

Metric	Earth	LTT 3780 b	Jupiter
Radius (R⊕)	1.00	1.33	11.21
Mass (M⊕)	1.00	2.46	317.83
Density (g/cm³)	5.51	5.80	1.33
Surface Gravity (g)	1.00	1.40	2.53
Insolation (S⊕)	1.00	111.00	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	2.460 M⊕	Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 36724087

Gaia DR2

Gaia DR2 3767281845873242112

Gaia DR3

Gaia DR3 3767281845873242112

System

LTT 3780

Percentile among Super-Earth cohort

Radius 1.325 R⊕ · percentile 11 / cohort 1176

Mass 2.460 M⊕ · percentile 18 / cohort 1176

Orbital period 0.77 d · percentile 3 / cohort 1164

Distance 21.98 pc · percentile 4 / cohort 1171

ESI 0.343 · percentile 49 / cohort 1176

Orbit & Habitability

Orbital Dynamics

Period

0.768 days

Semi-major axis

0.0120 AU

Eccentricity

0.000

Inclination

86.10 °

Year Length

A year here lasts roughly 18.4 hours long on a nearly circular orbit at a mean orbital distance of 0.0120 AU.

Transit Fingerprint

Depth

0.103 %

Duration

0.788 h

Impact parameter b

0.462

Rp / R★

0.032120

Transit midpoint (BJD)

2,459,606.5810

Photometric dip

Transit produces a flux drop of 1,032 ppm lasting ≈ 0.79 h.

Extended Orbital Architecture

Planet / star radius ratio

0.032120

Semi-major axis / stellar radius

6.790

Impact parameter (b)

0.462

RV semi-amplitude (K)

3.240 m/s

Transit mid-time (BJD)

2,459,606.5810

Long. of periastron (ω)

90.00°

Angular separation (arcsec)

0.54400

Eq. Temperature

903K

(630 °C)

Insolation (S⊕)

111.00

Earth = 1.00

Earth Similarity (ESI)

0.343

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

Cloutier et al. 2020

Instrument

TESS CCD Array

Publication

2020-07

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 TOI-540 b · Rocky Terrestrial LHS 1815 b · Rocky Terrestrial

Host System: LTT 3780

Spectral Class

M-type red dwarf

Effective Temperature

3,358 K — cooler than the Sun (5,778 K)

Estimated Age

3.10 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

0.380 R☉

Stellar Mass

0.381 M☉

Metallicity [Fe/H]

0.06

Extended Stellar Properties

Surface gravity (log g)

4.850 dex

Stellar density

9.784 g/cm³

Systemic radial velocity

0.27 km/s

Rotational v·sin i

1.30 km/s

Rotation period

104.00 days

Metallicity ratio

[Fe/H]

Distance

21.98 parsec

Light-years 71.69 ly

V-band magnitude

13.14 mag

Voyager-speed travel 1,264,318 yr

Multi-band Host Photometry — 11 bands

Astrometric Data

Parallax

45.464 mas

Total Proper Motion

421.900 mas/yr

PM Right Ascension

-341.41 mas/yr

PM Declination

-247.87 mas/yr

Galactic Cartesian (pc)

x = -0.885 · y = 0.419 · z = -0.203

Equatorial (J2000)

RA 154.64490° · Dec -11.71780°

Galactic ℓ, b

254.201° · 36.305°

Ecliptic λ, β

161.040° · -20.678°

HTM-20 index

229112000