Key parameters at a glance
- A radius of 2.46 Earth radii
- A mass of 8.90 Earth masses
- Surface gravity around 1.47 g
- An orbital period of 2.228 days
- Semi-major axis 0.0330 AU
- Equilibrium temperature 1,538 K (1265 °C)
- Distance from Earth 546.63 light-years
- Earth Similarity Index 0.160
- Travel time at Voyager 1 speed 9,639,836 years
2 siblings around TOI-1117
TOI-1117 b shares its host star with 2 other confirmed planets. Side-by-side measurements below.
| Planet | Type | Radius (R⊕) | Mass (M⊕) | Period (d) | Eq. T (K) | Year |
|---|---|---|---|---|---|---|
| TOI-1117 b this | Sub-Neptune | 2.46 | 8.90 | 2.228 | 1,538 | 2025 |
| TOI-1117 c | Sub-Neptune | 2.91 | 8.78 | 4.579 | 1,210 | 2025 |
| TOI-1117 d | Sub-Neptune | 3.27 | 10.71 | 8.665 | 978 | 2025 |
TOI-1117 b Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#1245of 1978
top 62.9%
This planet
2.46R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | TOI-1117 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 2.46 | 11.21 |
| Mass (M⊕) | 1.00 | 8.90 | 317.83 |
| Density (g/cm³) | 5.51 | 3.30 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.47 | 2.53 |
| Insolation (S⊕) | 1.00 | 928.00 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 8.900 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
TIC
TIC 295541511
Gaia DR2
Gaia DR2 6436995652638923392
Gaia DR3
Gaia DR3 6436995652638923392
System
TOI-1117
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 2.23 Earth days (0.6% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0330 AU.
Transit Fingerprint
Depth
0.063 %
Duration
2.015 h
Impact parameter b
0.170
Transit midpoint (BJD)
2,459,386.9640
Photometric dip
Transit produces a flux drop of 630 ppm lasting ≈ 2.02 h.
Extended Orbital Architecture
Impact parameter (b)
0.170
RV semi-amplitude (K)
4.450 m/s
Transit mid-time (BJD)
2,459,386.9640
Angular separation (arcsec)
0.19700
Eq. Temperature
1,538K
(1265 °C)
Insolation (S⊕)
928.00
Earth = 1.00
Earth Similarity (ESI)
0.160
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
Lockley et al. 2025Instrument
TESS CCD Array
Publication
2025-06
Observation locale
Space
Discovery cohort
Planets confirmed in 2025 at Transiting Exoplanet Survey Satellite (TESS) (12 shown).
Host System: TOI-1117
Spectral Class
G-type yellow (Sun-like)
Effective Temperature
5,635 K — cooler than the Sun (5,778 K)
Estimated Age
4.42 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
1.050 R☉
Stellar Mass
0.970 M☉
Metallicity [Fe/H]
0.14
Extended Stellar Properties
Surface gravity (log g)
4.410 dex
Stellar density
1.280 g/cm³
Rotational v·sin i
1.32 km/s
Rotation period
40.00 days
Activity index (log R'HK)
-5.030
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 11 bands
Astrometric Data
Parallax
5.938 mas
Total Proper Motion
41.569 mas/yr
PM Right Ascension
-15.32 mas/yr
PM Declination
-38.64 mas/yr
Galactic Cartesian (pc)
x = 0.025 · y = -0.399 · z = -0.917
Equatorial (J2000)
RA 273.60206° · Dec -66.41997°
Galactic ℓ, b
327.975° · -21.139°
Ecliptic λ, β
271.966° · -43.005°
HTM-20 index
842352940
Similar Worlds
Kepler-751 b
Sub-Neptune · G-type yellow (Sun-like)
Radius 2.46 R⊕ · 2,480.2 ly
Kepler-397 b
Sub-Neptune · G-type yellow (Sun-like)
Radius 2.46 R⊕ · 3,160.5 ly
Kepler-282 d
Sub-Neptune · G-type yellow (Sun-like)
Radius 2.46 R⊕ · 4,362.7 ly
Kepler-933 b
Sub-Neptune · G-type yellow (Sun-like)
Radius 2.46 R⊕ · 3,317.7 ly
Kepler-263 c
Sub-Neptune · G-type yellow (Sun-like)
Radius 2.47 R⊕ · 2,461.7 ly
Kepler-1101 b
Sub-Neptune · G-type yellow (Sun-like)
Radius 2.47 R⊕ · 2,421.6 ly