Key parameters at a glance

A radius of 11.75 Earth radii
A mass of 66.11 Earth masses
Surface gravity around 0.48 g
An orbital period of 7.533 days
Semi-major axis 0.0757 AU
Equilibrium temperature 1,257 K (984 °C)
Distance from Earth 1,456.10 light-years
Earth Similarity Index 0.089
Travel time at Voyager 1 speed 25,678,276 years

NGTS-12 b Planet Profile

Physical Specs

Radius

11.75 R⊕

Radius (Jupiter)

1.048 R♃

Mass

66.11 M⊕

Mass (Jupiter)

0.208 M♃

Density

0.22 g/cm³

Surface Gravity

0.48 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.089

HZ Position Inner

Controversial No

Discovery

Year 2020

Method Transit

Facility Next-Generation Transit Survey (NGTS)

Telescope 20 cm NGTS telescope

Size rank in cohort

Rank by radius

#1566of 1771

top 88.4%

This planet

11.75R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

HAT-P-17 b 11.77 R⊕ WASP-57 b 11.77 R⊕ TOI-2379 b 11.72 R⊕

Metric	Earth	NGTS-12 b	Jupiter
Radius (R⊕)	1.00	11.75	11.21
Mass (M⊕)	1.00	66.11	317.83
Density (g/cm³)	5.51	0.22	1.33
Surface Gravity (g)	1.00	0.48	2.53
Insolation (S⊕)	1.00	416.00	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	66.109 M⊕	Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 157230659

Gaia DR2

Gaia DR2 3464620139089832960

Gaia DR3

Gaia DR3 3464620139089832960

System

NGTS-12

Percentile among Gas Giant cohort

Radius 11.747 R⊕ · percentile 12 / cohort 1771

Mass 66.109 M⊕ · percentile 1 / cohort 1747

Orbital period 7.53 d · percentile 42 / cohort 1533

Distance 446.44 pc · percentile 73 / cohort 1759

ESI 0.089 · percentile 22 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period

7.533 days

Semi-major axis

0.0757 AU

Eccentricity

0.000

Inclination

88.90 °

Year Length

A year here lasts approximately 7.53 Earth days (2.1% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0757 AU.

Transit Fingerprint

Depth

0.470 %

Duration

5.850 h

Impact parameter b

0.200

Rp / R★

0.067800

Transit midpoint (BJD)

2,458,572.8549

Photometric dip

Transit produces a flux drop of 4,697 ppm lasting ≈ 5.85 h.

Extended Orbital Architecture

Planet / star radius ratio

0.067800

Semi-major axis / stellar radius

10.280

Impact parameter (b)

0.200

RV semi-amplitude (K)

21.300 m/s

Transit mid-time (BJD)

2,458,572.8549

Angular separation (arcsec)

0.17000

Eq. Temperature

1,257K

(984 °C)

Insolation (S⊕)

416.00

Earth = 1.00

Earth Similarity (ESI)

0.089

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

Bryant et al. 2020

Instrument

NGTS CCD array

Publication

2020-09

Observation locale

Ground

Host System: NGTS-12

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,690 K — cooler than the Sun (5,778 K)

Estimated Age

9.40 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

1.589 R☉

Stellar Mass

1.021 M☉

Metallicity [Fe/H]

-0.03

Extended Stellar Properties

Surface gravity (log g)

4.045 dex

Stellar density

0.359 g/cm³

Systemic radial velocity

-12.60 km/s

Rotational v·sin i

0.50 km/s

Metallicity ratio

[Fe/H]

Distance

446.44 parsec

Light-years 1,456.10 ly

V-band magnitude

12.38 mag

Voyager-speed travel 25,678,276 yr

Multi-band Host Photometry — 11 bands

Astrometric Data

Parallax

2.212 mas

Total Proper Motion

19.749 mas/yr

PM Right Ascension

-18.41 mas/yr

PM Declination

7.14 mas/yr

Galactic Cartesian (pc)

x = -0.811 · y = 0.053 · z = -0.583

Equatorial (J2000)

RA 176.24994° · Dec -35.64056°

Galactic ℓ, b

288.042° · 25.303°

Ecliptic λ, β

192.714° · -33.763°

HTM-20 index

-469006290