Confirmed Exoplanet Discovered 2024

NGTS-27 b

A gas giant orbiting the g-type yellow (sun-like) NGTS-27, located approximately 3,072.8 light-years from Earth.

Key parameters at a glance

  • A radius of 15.65 Earth radii
  • A mass of 188.47 Earth masses
  • Surface gravity around 0.77 g
  • An orbital period of 3.370 days
  • Semi-major axis 0.0446 AU
  • Equilibrium temperature 1,783 K (1510 °C)
  • Distance from Earth 3,072.79 light-years
  • Earth Similarity Index 0.057
  • Travel time at Voyager 1 speed 54,188,603 years

NGTS-27 b Planet Profile

Physical Specs

Radius
15.65 R⊕
Radius (Jupiter)
1.396 R♃
Mass
188.47 M⊕
Mass (Jupiter)
0.593 M♃
Density
0.27 g/cm³
Surface Gravity
0.77 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.057
HZ Position Inner
Controversial No

Discovery

Year 2024
Method Transit
Facility Transiting Exoplanet Survey Satellite (TESS)
Telescope 0.1 m TESS Telescope

Size rank in cohort

Rank by radius

#189of 1771

top 10.6%

This planet

15.65R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

Metric Earth NGTS-27 b Jupiter
Radius (R⊕)1.0015.6511.21
Mass (M⊕)1.00188.47317.83
Density (g/cm³)5.510.271.33
Surface Gravity (g)1.000.772.53
Insolation (S⊕)1.001,680.000.037

Alternative Mass Estimates

Method Value Interpretation
Best measured mass 188.472 M⊕ Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 305739565

Gaia DR2

Gaia DR2 6171451912217279872

Gaia DR3

Gaia DR3 6171451912217279872

System

NGTS-27

Percentile among Gas Giant cohort

Radius 15.648 R⊕ · percentile 89 / cohort 1771
Mass 188.472 M⊕ · percentile 18 / cohort 1747
Orbital period 3.37 d · percentile 21 / cohort 1533
Distance 942.12 pc · percentile 86 / cohort 1759
ESI 0.057 · percentile 7 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period
3.370 days
Semi-major axis
0.0446 AU
Eccentricity
0.000
Inclination
86.20 °

Year Length

A year here lasts approximately 3.37 Earth days (0.9% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0446 AU.

Transit Fingerprint

Depth

0.561 %

Duration

4.888 h

Rp / R★

0.081000

Transit midpoint (BJD)

2,458,540.6573

Photometric dip

Transit produces a flux drop of 5,610 ppm lasting ≈ 4.89 h.

Extended Orbital Architecture

Planet / star radius ratio

0.081000

Semi-major axis / stellar radius

5.430

RV semi-amplitude (K)

76.500 m/s

Transit mid-time (BJD)

2,458,540.6573

Angular separation (arcsec)

0.04730

Eq. Temperature

1,783K

(1510 °C)

Insolation (S⊕)

1,680.00

Earth = 1.00

Earth Similarity (ESI)

0.057

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

Bouchy et al. 2024

Instrument

TESS CCD Array

Publication

2024-04

Observation locale

Space

Host System: NGTS-27

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,700 K — cooler than the Sun (5,778 K)

Estimated Age

7.90 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

1.770 R☉

Stellar Mass

1.070 M☉

Metallicity [Fe/H]

0.00

Extended Stellar Properties

Surface gravity (log g)

4.050 dex

Stellar density

0.230 g/cm³

Systemic radial velocity

-22.90 km/s

Rotational v·sin i

1.60 km/s

Metallicity ratio

[Fe/H]

Distance
942.12 parsec
Light-years 3,072.79 ly
V-band magnitude
13.52 mag
Voyager-speed travel 54,188,603 yr

Multi-band Host Photometry — 11 bands

9.314.214.21B13.52V13.35Gaia12.89TESS12.25J11.86H11.86K11.82W111.86W211.75W39.26W4

Astrometric Data

Parallax

1.033 mas

Total Proper Motion

20.503 mas/yr

PM Right Ascension

-20.44 mas/yr

PM Declination

1.60 mas/yr

Galactic Cartesian (pc)

x = -0.758 · y = -0.370 · z = -0.538

Equatorial (J2000)

RA 206.02653° · Dec -32.52297°

Galactic ℓ, b

315.623° · 29.047°

Ecliptic λ, β

216.136° · -20.249°

HTM-20 index

-935182415

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