Key parameters at a glance

A radius of 16.59 Earth radii
A mass of 756.44 Earth masses
Surface gravity around 2.75 g
An orbital period of 1.675 days
Semi-major axis 0.0230 AU
Equilibrium temperature 1,434 K (1161 °C)
Distance from Earth 2,426.51 light-years
Earth Similarity Index 0.069
Travel time at Voyager 1 speed 42,791,489 years

NGTS-3 A b Planet Profile

Physical Specs

Radius

16.59 R⊕

Radius (Jupiter)

1.480 R♃

Mass

756.44 M⊕

Mass (Jupiter)

2.380 M♃

Density

0.31 g/cm³

Surface Gravity

2.75 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.069

HZ Position Inner

Controversial No

Discovery

Year 2018

Method Transit

Facility Next-Generation Transit Survey (NGTS)

Telescope 20 cm NGTS telescope

Size rank in cohort

Rank by radius

#129of 1771

top 7.2%

This planet

16.59R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

HAT-P-6 b 16.59 R⊕ TOI-5322 b 16.61 R⊕ Kepler-718 b 16.56 R⊕

Metric	Earth	NGTS-3 A b	Jupiter
Radius (R⊕)	1.00	16.59	11.21
Mass (M⊕)	1.00	756.44	317.83
Density (g/cm³)	5.51	0.31	1.33
Surface Gravity (g)	1.00	2.75	2.53
Insolation (S⊕)	1.00	1,000.57	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	756.435 M⊕	Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 124778445

Gaia DR2

Gaia DR2 2885350546895266432

Gaia DR3

Gaia DR3 2885350546895266432

System

NGTS-3

Percentile among Gas Giant cohort

Radius 16.589 R⊕ · percentile 93 / cohort 1771

Mass 756.435 M⊕ · percentile 60 / cohort 1747

Orbital period 1.68 d · percentile 4 / cohort 1533

Distance 743.97 pc · percentile 82 / cohort 1759

ESI 0.069 · percentile 13 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period

1.675 days

Semi-major axis

0.0230 AU

Eccentricity

—

Inclination

89.56 °

Year Length

A year here lasts approximately 1.68 Earth days (0.5% of a terrestrial year) at a mean orbital distance of 0.0230 AU.

Transit Fingerprint

Depth

2.680 %

Duration

2.300 h

Impact parameter b

0.050

Rp / R★

0.163800

Transit midpoint (BJD)

2,457,620.1679

Photometric dip

Transit produces a flux drop of 26,800 ppm lasting ≈ 2.30 h.

Extended Orbital Architecture

Planet / star radius ratio

0.163800

Semi-major axis / stellar radius

6.494

Impact parameter (b)

0.050

RV semi-amplitude (K)

-404.000 m/s

Transit mid-time (BJD)

2,457,620.1679

Angular separation (arcsec)

0.03090

Eq. Temperature

1,434K

(1161 °C)

Insolation (S⊕)

1,000.57

Earth = 1.00

Earth Similarity (ESI)

0.069

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

G Uuml Nther et al. 2018

Instrument

NGTS CCD array

Publication

2018-08

Observation locale

Ground

Host System: NGTS-3 A

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,600 K — cooler than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

0.930 R☉

Stellar Mass

1.017 M☉

Metallicity [Fe/H]

0.12

Extended Stellar Properties

Surface gravity (log g)

4.448 dex

Stellar density

1.090 g/cm³

Systemic radial velocity

8.57 km/s

Rotational v·sin i

1.00 km/s

Metallicity ratio

[Fe/H]

Distance

743.97 parsec

Light-years 2,426.51 ly

V-band magnitude

14.67 mag

Voyager-speed travel 42,791,489 yr

Multi-band Host Photometry — 14 bands

Astrometric Data

Parallax

1.315 mas

Total Proper Motion

12.452 mas/yr

PM Right Ascension

-8.84 mas/yr

PM Declination

8.77 mas/yr

Galactic Cartesian (pc)

x = -0.063 · y = 0.810 · z = -0.584

Equatorial (J2000)

RA 94.44476° · Dec -35.70636°

Galactic ℓ, b

243.010° · -21.832°

Ecliptic λ, β

97.022° · -59.037°

HTM-20 index

-1314350905