Key parameters at a glance
- A radius of 2.93 Earth radii
- A mass of 13.60 Earth masses
- Surface gravity around 1.58 g
- An orbital period of 19.980 days
- Semi-major axis 0.1370 AU
- Equilibrium temperature 638 K (365 °C)
- Distance from Earth 362.23 light-years
- Earth Similarity Index 0.393
- Travel time at Voyager 1 speed 6,387,848 years
- Almost certainly tidally locked to its host star given the close orbit
2 siblings around TOI-125
TOI-125 d shares its host star with 2 other confirmed planets. Side-by-side measurements below.
TOI-125 d Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#585of 1978
top 29.5%
This planet
2.93R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | TOI-125 d | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 2.93 | 11.21 |
| Mass (M⊕) | 1.00 | 13.60 | 317.83 |
| Density (g/cm³) | 5.51 | 2.98 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.58 | 2.53 |
| Insolation (S⊕) | 1.00 | 26.70 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 13.600 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
TIC
TIC 52368076
Gaia DR2
Gaia DR2 4698692744355471616
Gaia DR3
Gaia DR3 4698692748651744128
System
TOI-125
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 19.98 Earth days (5.5% of a terrestrial year) on a mildly elliptical path at a mean orbital distance of 0.1370 AU.
Transit Fingerprint
Depth
0.100 %
Duration
3.113 h
Impact parameter b
0.652
Rp / R★
0.031700
Transit midpoint (BJD)
2,458,342.8516
Photometric dip
Transit produces a flux drop of 1,000 ppm lasting ≈ 3.11 h.
Extended Orbital Architecture
Planet / star radius ratio
0.031700
Semi-major axis / stellar radius
34.770
Impact parameter (b)
0.652
RV semi-amplitude (K)
3.610 m/s
Transit mid-time (BJD)
2,458,342.8516
Long. of periastron (ω)
46.00°
Angular separation (arcsec)
1.23000
Eq. Temperature
638K
(365 °C)
Insolation (S⊕)
26.70
Earth = 1.00
Earth Similarity (ESI)
0.393
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
Nielsen et al. 2020Instrument
TESS CCD Array
Publication
2020-03
Observation locale
Space
Discovery cohort
Planets confirmed in 2020 at Transiting Exoplanet Survey Satellite (TESS) (12 shown).
Host System: TOI-125
Spectral Class
K-type orange
Effective Temperature
5,320 K — cooler than the Sun (5,778 K)
Estimated Age
6.80 Gyr — older than the Sun (4.6 Gyr)
Stellar Radius
0.848 R☉
Stellar Mass
0.859 M☉
Metallicity [Fe/H]
-0.02
Extended Stellar Properties
Surface gravity (log g)
4.516 dex
Stellar density
1.990 g/cm³
Systemic radial velocity
11.06 km/s
Rotational v·sin i
1.00 km/s
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 14 bands
Astrometric Data
Parallax
8.975 mas
Total Proper Motion
171.667 mas/yr
PM Right Ascension
-119.80 mas/yr
PM Declination
-122.95 mas/yr
Galactic Cartesian (pc)
x = 0.363 · y = 0.158 · z = -0.918
Equatorial (J2000)
RA 23.59343° · Dec -66.67635°
Galactic ℓ, b
296.358° · -49.900°
Ecliptic λ, β
328.779° · -64.896°
HTM-20 index
-852704894
Similar Worlds
K2-266 d
Sub-Neptune · K-type orange
Radius 2.93 R⊕ · 253.0 ly
HD 15906 c
Sub-Neptune · K-type orange
Radius 2.93 R⊕ · 148.6 ly
Kepler-1731 b
Sub-Neptune · K-type orange
Radius 2.93 R⊕ · 554.3 ly
TOI-824 b
Sub-Neptune · K-type orange
Radius 2.93 R⊕ · 208.5 ly
TOI-178 g
Sub-Neptune · K-type orange
Radius 2.94 R⊕ · 204.5 ly
TOI-815 b
Sub-Neptune · K-type orange
Radius 2.94 R⊕ · 194.8 ly