Key parameters at a glance

A radius of 1.80 Earth radii
A mass of 5.00 Earth masses
Surface gravity around 1.55 g
An orbital period of 8.247 days
Semi-major axis 0.0653 AU
Equilibrium temperature 520 K (247 °C)
Distance from Earth 88.62 light-years
Earth Similarity Index 0.555
Travel time at Voyager 1 speed 1,562,759 years
Almost certainly tidally locked to its host star given the close orbit

1 sibling around TOI-776

TOI-776 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
TOI-776 b this	Super-Earth	1.80	5.00	8.247	520	2020
TOI-776 c	Sub-Neptune	2.05	6.90	15.665	420	2020

TOI-776 b Planet Profile

Physical Specs

Radius

1.80 R⊕

Radius (Jupiter)

0.160 R♃

Mass

5.00 M⊕

Mass (Jupiter)

0.016 M♃

Density

4.80 g/cm³

Surface Gravity

1.55 g (Earth)

Classification

Planet Type

Super-Earth

ESI Score 0.555

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

#266of 1176

top 22.5%

This planet

1.80R⊕

Super-Earth median

1.60R⊕

Nearest-size peers

Kepler-11 b 1.80 R⊕ Kepler-148 b 1.80 R⊕ PSR B1257+12 d 1.80 R⊕

Metric	Earth	TOI-776 b	Jupiter
Radius (R⊕)	1.00	1.80	11.21
Mass (M⊕)	1.00	5.00	317.83
Density (g/cm³)	5.51	4.80	1.33
Surface Gravity (g)	1.00	1.55	2.53
Insolation (S⊕)	1.00	11.50	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	5.000 M⊕	Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 306996324

Gaia DR2

Gaia DR2 3460438662009633408

Gaia DR3

Gaia DR3 3460438662009633408

System

TOI-776

Percentile among Super-Earth cohort

Radius 1.798 R⊕ · percentile 77 / cohort 1176

Mass 5.000 M⊕ · percentile 92 / cohort 1176

Orbital period 8.25 d · percentile 59 / cohort 1164

Distance 27.17 pc · percentile 6 / cohort 1171

ESI 0.555 · percentile 77 / cohort 1176

Orbit & Habitability

Orbital Dynamics

Period

8.247 days

Semi-major axis

0.0653 AU

Eccentricity

0.052

Inclination

89.41 °

Year Length

A year here lasts approximately 8.25 Earth days (2.3% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0653 AU.

Transit Fingerprint

Depth

0.091 %

Duration

2.382 h

Impact parameter b

0.260

Rp / R★

0.031600

Transit midpoint (BJD)

2,459,288.8713

Photometric dip

Transit produces a flux drop of 909 ppm lasting ≈ 2.38 h.

Extended Orbital Architecture

Planet / star radius ratio

0.031600

Semi-major axis / stellar radius

27.870

Impact parameter (b)

0.260

RV semi-amplitude (K)

2.400 m/s

Transit mid-time (BJD)

2,459,288.8713

Long. of periastron (ω)

45.00°

Angular separation (arcsec)

2.40000

Eq. Temperature

520K

(247 °C)

Insolation (S⊕)

11.50

Earth = 1.00

Earth Similarity (ESI)

0.555

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

Luque 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-1266 b · Sub-Neptune TOI-540 b · Rocky Terrestrial LHS 1815 b · Rocky Terrestrial TOI-122 b · Sub-Neptune

Host System: TOI-776

Spectral Class

M-type red dwarf

Effective Temperature

3,725 K — cooler than the Sun (5,778 K)

Estimated Age

6.10 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

0.547 R☉

Stellar Mass

0.542 M☉

Metallicity [Fe/H]

-0.21

Extended Stellar Properties

Surface gravity (log g)

4.800 dex

Stellar density

6.024 g/cm³

Systemic radial velocity

49.34 km/s

Rotational v·sin i

2.20 km/s

Rotation period

21.13 days

Metallicity ratio

[Fe/H]

Distance

27.17 parsec

Light-years 88.62 ly

V-band magnitude

11.54 mag

Voyager-speed travel 1,562,759 yr

Multi-band Host Photometry — 14 bands

Astrometric Data

Parallax

36.776 mas

Total Proper Motion

289.999 mas/yr

PM Right Ascension

251.11 mas/yr

PM Declination

-145.06 mas/yr

Galactic Cartesian (pc)

x = -0.793 · y = 0.020 · z = -0.609

Equatorial (J2000)

RA 178.57800° · Dec -37.55336°

Galactic ℓ, b

290.576° · 23.944°

Ecliptic λ, β

195.805° · -34.543°

HTM-20 index

-1090054726