Confirmed Exoplanet Discovered 2023

TOI-4860 b

A neptune-like orbiting the m-type red dwarf TOI-4860, located approximately 261.4 light-years from Earth.

Key parameters at a glance

  • A radius of 8.70 Earth radii
  • A mass of 86.70 Earth masses
  • Surface gravity around 1.15 g
  • An orbital period of 1.523 days
  • Semi-major axis 0.0181 AU
  • Equilibrium temperature 694 K (421 °C)
  • Distance from Earth 261.39 light-years
  • Earth Similarity Index 0.228
  • Travel time at Voyager 1 speed 4,609,593 years
  • Almost certainly tidally locked to its host star given the close orbit

TOI-4860 b Planet Profile

Physical Specs

Radius
8.70 R⊕
Radius (Jupiter)
0.770 R♃
Mass
86.70 M⊕
Mass (Jupiter)
0.273 M♃
Density
0.75 g/cm³
Surface Gravity
1.15 g (Earth)

Classification

Planet Type

Neptune-like

ESI Score 0.228
HZ Position Inner
Controversial No

Discovery

Year 2023
Method Transit
Facility Transiting Exoplanet Survey Satellite (TESS)
Telescope 0.1 m TESS Telescope

Size rank in cohort

Rank by radius

#105of 574

top 18.1%

This planet

8.70R⊕

Neptune-like median

6.39R⊕

Nearest-size peers

Metric Earth TOI-4860 b Jupiter
Radius (R⊕)1.008.7011.21
Mass (M⊕)1.0086.70317.83
Density (g/cm³)5.510.751.33
Surface Gravity (g)1.001.152.53
Insolation (S⊕)1.0042.500.037

Alternative Mass Estimates

Method Value Interpretation
Best measured mass 86.700 M⊕ Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 335590096

Gaia DR2

Gaia DR2 3571038605366263424

Gaia DR3

Gaia DR3 3571038605366263424

System

TOI-4860

Percentile among Neptune-like cohort

Radius 8.700 R⊕ · percentile 82 / cohort 574
Mass 86.700 M⊕ · percentile 89 / cohort 574
Orbital period 1.52 d · percentile 1 / cohort 524
Distance 80.14 pc · percentile 22 / cohort 572
ESI 0.228 · percentile 34 / cohort 574

Orbit & Habitability

Orbital Dynamics

Period
1.523 days
Semi-major axis
0.0181 AU
Eccentricity
0.008
Inclination
88.50 °

Year Length

A year here lasts approximately 1.52 Earth days (0.4% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0181 AU.

Transit Fingerprint

Depth

5.806 %

Duration

1.231 h

Impact parameter b

0.290

Rp / R★

0.222800

Transit midpoint (BJD)

2,460,036.6912

Photometric dip

Transit produces a flux drop of 58,060 ppm lasting ≈ 1.23 h.

Extended Orbital Architecture

Planet / star radius ratio

0.222800

Semi-major axis / stellar radius

11.000

Impact parameter (b)

0.290

RV semi-amplitude (K)

98.900 m/s

Transit mid-time (BJD)

2,460,036.6912

Long. of periastron (ω)

240.00°

Angular separation (arcsec)

0.22600

Eq. Temperature

694K

(421 °C)

Insolation (S⊕)

42.50

Earth = 1.00

Earth Similarity (ESI)

0.228

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

Triaud et al. 2023

Instrument

TESS CCD Array

Publication

2023-10

Observation locale

Space

Host System: TOI-4860

Spectral Class

M-type red dwarf

Effective Temperature

3,260 K — cooler than the Sun (5,778 K)

Estimated Age

4.50 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

0.358 R☉

Stellar Mass

0.340 M☉

Metallicity [Fe/H]

0.27

Extended Stellar Properties

Surface gravity (log g)

4.860 dex

Stellar density

11.700 g/cm³

Activity index (log R'HK)

-5.650

Metallicity ratio

[Fe/H]

Distance
80.14 parsec
Light-years 261.39 ly
V-band magnitude
16.47 mag
Voyager-speed travel 4,609,593 yr

Multi-band Host Photometry — 10 bands

8.416.516.47V15.11Gaia13.77TESS12.06J11.43H11.18K11.02W110.89W210.96W38.38W4

Astrometric Data

Parallax

12.450 mas

Total Proper Motion

177.330 mas/yr

PM Right Ascension

-177.24 mas/yr

PM Declination

-5.52 mas/yr

Galactic Cartesian (pc)

x = -0.972 · y = -0.061 · z = -0.228

Equatorial (J2000)

RA 183.56396° · Dec -13.17484°

Galactic ℓ, b

289.146° · 48.699°

Ecliptic λ, β

188.551° · -10.663°

HTM-20 index

-1350582321

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