Key parameters at a glance
- A radius of 6.60 Earth radii
- A mass of 32.00 Earth masses
- Surface gravity around 0.73 g
- An orbital period of 6.754 days
- Semi-major axis 0.0730 AU
- Equilibrium temperature 1,180 K (907 °C)
- Distance from Earth 427.00 light-years
- Earth Similarity Index 0.134
- Travel time at Voyager 1 speed 7,530,148 years
TOI-5108 b Planet Profile
Physical Specs
Classification
Planet Type
Neptune-like
Discovery
Size rank in cohort
Rank by radius
#230of 574
top 39.9%
This planet
6.60R⊕
Neptune-like median
6.39R⊕
Nearest-size peers
| Metric | Earth | TOI-5108 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 6.60 | 11.21 |
| Mass (M⊕) | 1.00 | 32.00 | 317.83 |
| Density (g/cm³) | 5.51 | 0.60 | 1.33 |
| Surface Gravity (g) | 1.00 | 0.73 | 2.53 |
| Insolation (S⊕) | 1.00 | 122.79 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 32.000 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
HIP
HIP 54186
TIC
TIC 350348197
Gaia DR2
Gaia DR2 3868491612036282752
Gaia DR3
Gaia DR3 3868491612036282752
System
TOI-5108
Percentile among Neptune-like cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 6.75 Earth days (1.8% of a terrestrial year) at a mean orbital distance of 0.0730 AU.
Transit Fingerprint
Depth
0.174 %
Duration
2.200 h
Impact parameter b
0.871
Rp / R★
0.047200
Transit midpoint (BJD)
2,459,569.4778
Photometric dip
Transit produces a flux drop of 1,740 ppm lasting ≈ 2.20 h.
Extended Orbital Architecture
Planet / star radius ratio
0.047200
Semi-major axis / stellar radius
12.200
Impact parameter (b)
0.871
RV semi-amplitude (K)
9.900 m/s
Transit mid-time (BJD)
2,459,569.4778
Angular separation (arcsec)
0.55800
Eq. Temperature
1,180K
(907 °C)
Insolation (S⊕)
122.79
Earth = 1.00
Earth Similarity (ESI)
0.134
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
Thomas et al. 2025Instrument
TESS CCD Array
Publication
2025-01
Observation locale
Space
Discovery cohort
Planets confirmed in 2025 at Transiting Exoplanet Survey Satellite (TESS) (12 shown).
Host System: TOI-5108
Spectral Class
G-type yellow (Sun-like)
Effective Temperature
5,808 K — hotter than the Sun (5,778 K)
Estimated Age
5.80 Gyr — older than the Sun (4.6 Gyr)
Stellar Radius
1.290 R☉
Stellar Mass
1.100 M☉
Metallicity [Fe/H]
0.20
Extended Stellar Properties
Surface gravity (log g)
4.260 dex
Stellar density
0.745 g/cm³
Rotational v·sin i
3.30 km/s
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 16 bands
Astrometric Data
Parallax
7.611 mas
Total Proper Motion
82.056 mas/yr
PM Right Ascension
67.55 mas/yr
PM Declination
-46.58 mas/yr
Galactic Cartesian (pc)
x = -0.953 · y = 0.233 · z = 0.195
Equatorial (J2000)
RA 166.26950° · Dec 11.24641°
Galactic ℓ, b
240.208° · 60.401°
Ecliptic λ, β
163.003° · 4.953°
HTM-20 index
460813678
Similar Worlds
TOI-4940 b
Neptune-like · G-type yellow (Sun-like)
Radius 6.61 R⊕ · 1,127.4 ly
K2-19 b
Neptune-like · G-type yellow (Sun-like)
Radius 6.59 R⊕ · 945.3 ly
Kepler-767 b
Neptune-like · G-type yellow (Sun-like)
Radius 6.64 R⊕ · 7,341.9 ly
Kepler-673 b
Neptune-like · G-type yellow (Sun-like)
Radius 6.54 R⊕ · 2,994.8 ly
Kepler-297 c
Neptune-like · G-type yellow (Sun-like)
Radius 6.54 R⊕ · 2,257.5 ly
Kepler-139 f
Neptune-like · G-type yellow (Sun-like)
Radius 6.67 R⊕ · 1,275.4 ly