Key parameters at a glance
- A radius of 1.56 Earth radii
- A mass of 3.37 Earth masses
- Surface gravity around 1.39 g
- An orbital period of 1.273 days
- Semi-major axis 0.0212 AU
- Equilibrium temperature 1,378 K (1105 °C)
- Distance from Earth 262.69 light-years
- Earth Similarity Index 0.205
- Travel time at Voyager 1 speed 4,632,508 years
- Almost certainly tidally locked to its host star given the close orbit
1 sibling around TOI-238
TOI-238 b shares its host star with 1 other confirmed planet. Side-by-side measurements below.
| Planet | Type | Radius (R⊕) | Mass (M⊕) | Period (d) | Eq. T (K) | Year |
|---|---|---|---|---|---|---|
| TOI-238 b this | Super-Earth | 1.56 | 3.37 | 1.273 | 1,378 | 2024 |
| TOI-238 c | Sub-Neptune | 2.18 | 6.70 | 8.466 | 696 | 2024 |
TOI-238 b Planet Profile
Physical Specs
Classification
Planet Type
Super-Earth
Discovery
Size rank in cohort
Rank by radius
#648of 1176
top 55.0%
This planet
1.56R⊕
Super-Earth median
1.60R⊕
Nearest-size peers
| Metric | Earth | TOI-238 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 1.56 | 11.21 |
| Mass (M⊕) | 1.00 | 3.37 | 317.83 |
| Density (g/cm³) | 5.51 | 6.80 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.39 | 2.53 |
| Insolation (S⊕) | 1.00 | 753.10 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 3.370 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
TIC
TIC 9006668
Gaia DR2
Gaia DR2 2405081733281425280
Gaia DR3
Gaia DR3 2405081733281425280
System
TOI-238
Percentile among Super-Earth cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 1.27 Earth days (0.3% of a terrestrial year) on a mildly elliptical path at a mean orbital distance of 0.0212 AU.
Transit Fingerprint
Depth
0.041 %
Duration
1.587 h
Impact parameter b
0.230
Rp / R★
0.018910
Transit midpoint (BJD)
2,460,205.7524
Photometric dip
Transit produces a flux drop of 414 ppm lasting ≈ 1.59 h.
Extended Orbital Architecture
Planet / star radius ratio
0.018910
Semi-major axis / stellar radius
6.030
Impact parameter (b)
0.230
RV semi-amplitude (K)
2.360 m/s
Transit mid-time (BJD)
2,460,205.7524
Angular separation (arcsec)
0.26300
Eq. Temperature
1,378K
(1105 °C)
Insolation (S⊕)
753.10
Earth = 1.00
Earth Similarity (ESI)
0.205
0 = alien, 1 = Earth-identical
Inside the inner HZ boundary (too hot for liquid water) — the dayside is scorched. 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
Su Aacute Rez Mascare Ntilde O et al. 2024Instrument
TESS CCD Array
Publication
2024-02
Observation locale
Space
Discovery cohort
Planets confirmed in 2024 at Transiting Exoplanet Survey Satellite (TESS) (12 shown).
Host System: TOI-238
Spectral Class
K-type orange
Effective Temperature
5,059 K — cooler than the Sun (5,778 K)
Estimated Age
7.90 Gyr — older than the Sun (4.6 Gyr)
Stellar Radius
0.756 R☉
Stellar Mass
0.781 M☉
Metallicity [Fe/H]
-0.11
Extended Stellar Properties
Surface gravity (log g)
4.580 dex
Stellar density
2.640 g/cm³
Rotational v·sin i
2.30 km/s
Rotation period
26.00 days
Activity index (log R'HK)
-4.740
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 11 bands
Astrometric Data
Parallax
12.387 mas
Total Proper Motion
53.238 mas/yr
PM Right Ascension
-53.24 mas/yr
PM Declination
-0.20 mas/yr
Galactic Cartesian (pc)
x = 0.931 · y = -0.177 · z = -0.319
Equatorial (J2000)
RA 349.23108° · Dec -18.60665°
Galactic ℓ, b
49.354° · -66.671°
Ecliptic λ, β
342.730° · -12.844°
HTM-20 index
986030315
Similar Worlds
TOI-5736 b
Super-Earth · K-type orange
Radius 1.56 R⊕ · 301.2 ly
Kepler-1317 b
Super-Earth · K-type orange
Radius 1.56 R⊕ · 2,375.4 ly
Kepler-190 b
Super-Earth · K-type orange
Radius 1.56 R⊕ · 1,413.5 ly
K2-165 c
Super-Earth · K-type orange
Radius 1.55 R⊕ · 439.0 ly
K2-383 b
Super-Earth · K-type orange
Radius 1.56 R⊕ · 664.7 ly
K2-136 d
Super-Earth · K-type orange
Radius 1.57 R⊕ · 193.2 ly