Confirmed Exoplanet Discovered 2020

TOI-157 b

A gas giant orbiting the g-type yellow (sun-like) TOI-157, located approximately 1,160.1 light-years from Earth.

Key parameters at a glance

  • A radius of 14.41 Earth radii
  • A mass of 375.04 Earth masses
  • Surface gravity around 1.80 g
  • An orbital period of 2.085 days
  • Semi-major axis 0.0314 AU
  • Equilibrium temperature 1,588 K (1315 °C)
  • Distance from Earth 1,160.08 light-years
  • Earth Similarity Index 0.079
  • Travel time at Voyager 1 speed 20,458,035 years

TOI-157 b Planet Profile

Physical Specs

Radius
14.41 R⊕
Radius (Jupiter)
1.286 R♃
Mass
375.04 M⊕
Mass (Jupiter)
1.180 M♃
Density
0.69 g/cm³
Surface Gravity
1.80 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.079
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

#288of 1771

top 16.2%

This planet

14.41R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

Metric Earth TOI-157 b Jupiter
Radius (R⊕)1.0014.4111.21
Mass (M⊕)1.00375.04317.83
Density (g/cm³)5.510.691.33
Surface Gravity (g)1.001.802.53
Insolation (S⊕)1.001,062.000.037

Alternative Mass Estimates

Method Value Interpretation
Best measured mass 375.039 M⊕ Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 140691463

Gaia DR2

Gaia DR2 4624979393181971328

Gaia DR3

Gaia DR3 4624979393181971328

System

TOI-157

Percentile among Gas Giant cohort

Radius 14.415 R⊕ · percentile 84 / cohort 1771
Mass 375.039 M⊕ · percentile 40 / cohort 1747
Orbital period 2.08 d · percentile 7 / cohort 1533
Distance 355.68 pc · percentile 66 / cohort 1759
ESI 0.079 · percentile 18 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period
2.085 days
Semi-major axis
0.0314 AU
Eccentricity
0.000
Inclination
82.01 °

Year Length

A year here lasts approximately 2.08 Earth days (0.6% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0314 AU.

Transit Fingerprint

Depth

1.283 %

Duration

2.146 h

Impact parameter b

0.805

Rp / R★

0.113290

Transit midpoint (BJD)

2,458,326.5477

Photometric dip

Transit produces a flux drop of 12,830 ppm lasting ≈ 2.15 h.

Extended Orbital Architecture

Planet / star radius ratio

0.113290

Semi-major axis / stellar radius

5.785

Impact parameter (b)

0.805

RV semi-amplitude (K)

192.000 m/s

Transit mid-time (BJD)

2,458,326.5477

Angular separation (arcsec)

0.08820

Eq. Temperature

1,588K

(1315 °C)

Insolation (S⊕)

1,062.00

Earth = 1.00

Earth Similarity (ESI)

0.079

0 = alien, 1 = Earth-identical

Inside the inner HZ boundary (too hot for liquid water) — the dayside is scorched.

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

Nielsen et al. 2020

Instrument

TESS CCD Array

Publication

2020-07

Observation locale

Space

Host System: TOI-157

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,404 K — cooler than the Sun (5,778 K)

Estimated Age

12.82 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

1.167 R☉

Stellar Mass

0.948 M☉

Metallicity [Fe/H]

0.24

Extended Stellar Properties

Surface gravity (log g)

4.281 dex

Stellar density

0.842 g/cm³

Systemic radial velocity

-6.11 km/s

Rotational v·sin i

2.50 km/s

Metallicity ratio

[Fe/H]

Distance
355.68 parsec
Light-years 1,160.08 ly
V-band magnitude
12.73 mag
Voyager-speed travel 20,458,035 yr

Multi-band Host Photometry — 11 bands

9.513.513.45B12.73V12.51Gaia12.02TESS11.37J10.99H10.89K10.85W110.89W210.87W39.50W4

Astrometric Data

Parallax

2.783 mas

Total Proper Motion

22.254 mas/yr

PM Right Ascension

11.71 mas/yr

PM Declination

-18.92 mas/yr

Galactic Cartesian (pc)

x = 0.065 · y = 0.221 · z = -0.973

Equatorial (J2000)

RA 73.70144° · Dec -76.68061°

Galactic ℓ, b

289.063° · -32.930°

Ecliptic λ, β

289.337° · -78.742°

HTM-20 index

-1239837352

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