Key parameters at a glance
- A radius of 3.29 Earth radii
- A mass of 9.90 Earth masses
- Surface gravity around 0.91 g
- An orbital period of 12.461 days
- Semi-major axis 0.0980 AU
- Equilibrium temperature 633 K (360 °C)
- Distance from Earth 106.22 light-years
- Earth Similarity Index 0.344
- Travel time at Voyager 1 speed 1,873,268 years
- Almost certainly tidally locked to its host star given the close orbit
2 siblings around TOI-431
TOI-431 d shares its host star with 2 other confirmed planets. Side-by-side measurements below.
TOI-431 d Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#287of 1978
top 14.5%
This planet
3.29R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | TOI-431 d | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 3.29 | 11.21 |
| Mass (M⊕) | 1.00 | 9.90 | 317.83 |
| Density (g/cm³) | 5.51 | 1.36 | 1.33 |
| Surface Gravity (g) | 1.00 | 0.91 | 2.53 |
| Insolation (S⊕) | 1.00 | 28.36 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 9.900 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
HIP
HIP 26013
TIC
TIC 31374837
Gaia DR2
Gaia DR2 2908664557091200768
Gaia DR3
Gaia DR3 2908664557091200768
System
TOI-431
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 12.46 Earth days (3.4% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0980 AU.
Transit Fingerprint
Depth
0.208 %
Duration
3.320 h
Impact parameter b
0.150
Rp / R★
0.041000
Transit midpoint (BJD)
2,458,627.5453
Photometric dip
Transit produces a flux drop of 2,078 ppm lasting ≈ 3.32 h.
Extended Orbital Architecture
Planet / star radius ratio
0.041000
Semi-major axis / stellar radius
28.650
Impact parameter (b)
0.150
RV semi-amplitude (K)
3.160 m/s
Transit mid-time (BJD)
2,458,627.5453
Long. of periastron (ω)
0.00°
Angular separation (arcsec)
3.01000
Eq. Temperature
633K
(360 °C)
Insolation (S⊕)
28.36
Earth = 1.00
Earth Similarity (ESI)
0.344
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
Osborn et al. 2021Instrument
TESS CCD Array
Publication
2021-10
Observation locale
Space
Discovery cohort
Planets confirmed in 2021 at Transiting Exoplanet Survey Satellite (TESS) (12 shown).
Host System: TOI-431
Spectral Class
K-type orange
Effective Temperature
4,850 K — cooler than the Sun (5,778 K)
Estimated Age
—
Stellar Radius
0.731 R☉
Stellar Mass
0.780 M☉
Metallicity [Fe/H]
0.20
Extended Stellar Properties
Surface gravity (log g)
4.600 dex
Stellar density
2.940 g/cm³
Rotational v·sin i
2.50 km/s
Rotation period
30.50 days
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 11 bands
Astrometric Data
Parallax
30.675 mas
Total Proper Motion
151.700 mas/yr
PM Right Ascension
16.80 mas/yr
PM Declination
150.77 mas/yr
Galactic Cartesian (pc)
x = 0.105 · y = 0.887 · z = -0.450
Equatorial (J2000)
RA 83.26925° · Dec -26.72387°
Galactic ℓ, b
230.329° · -28.137°
Ecliptic λ, β
80.634° · -49.945°
HTM-20 index
556649667
Similar Worlds
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K2-266 b
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Kepler-411 e
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HD 18143 b
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Radius 3.30 R⊕ · 1,102.2 ly