Key parameters at a glance
- A radius of 2.46 Earth radii
- A mass of 9.50 Earth masses
- Surface gravity around 1.57 g
- An orbital period of 2.628 days
- Semi-major axis 0.0344 AU
- Equilibrium temperature 1,108 K (835 °C)
- Distance from Earth 139.94 light-years
- Earth Similarity Index 0.234
- Travel time at Voyager 1 speed 2,467,804 years
- Almost certainly tidally locked to its host star given the close orbit
TOI-5800 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-5800 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 2.46 | 11.21 |
| Mass (M⊕) | 1.00 | 9.50 | 317.83 |
| Density (g/cm³) | 5.51 | 3.46 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.57 | 2.53 |
| Insolation (S⊕) | 1.00 | 274.16 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 9.500 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
TIC
TIC 151759246
Gaia DR2
Gaia DR2 4216059714460162944
Gaia DR3
Gaia DR3 4216059714460162944
System
TOI-5800
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 2.63 Earth days (0.7% of a terrestrial year) on a highly eccentric trajectory at a mean orbital distance of 0.0344 AU.
Transit Fingerprint
Depth
0.073 %
Duration
1.200 h
Impact parameter b
0.903
Rp / R★
0.029200
Transit midpoint (BJD)
2,459,771.7145
Photometric dip
Transit produces a flux drop of 731 ppm lasting ≈ 1.20 h.
Extended Orbital Architecture
Planet / star radius ratio
0.029200
Semi-major axis / stellar radius
9.580
Impact parameter (b)
0.903
RV semi-amplitude (K)
5.400 m/s
Transit mid-time (BJD)
2,459,771.7145
Long. of periastron (ω)
-36.00°
Angular separation (arcsec)
0.80200
Eq. Temperature
1,108K
(835 °C)
Insolation (S⊕)
274.16
Earth = 1.00
Earth Similarity (ESI)
0.234
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
Jenkins et al. 2025Instrument
TESS CCD Array
Publication
2025-05
Observation locale
Space
Discovery cohort
Planets confirmed in 2025 at Transiting Exoplanet Survey Satellite (TESS) (12 shown).
Host System: TOI-5800
Spectral Class
K-type orange
Effective Temperature
4,850 K — cooler than the Sun (5,778 K)
Estimated Age
8.10 Gyr — older than the Sun (4.6 Gyr)
Stellar Radius
0.773 R☉
Stellar Mass
0.778 M☉
Metallicity [Fe/H]
-0.04
Extended Stellar Properties
Surface gravity (log g)
4.560 dex
Stellar density
2.410 g/cm³
Rotational v·sin i
1.30 km/s
Activity index (log R'HK)
-4.885
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 11 bands
Astrometric Data
Parallax
23.278 mas
Total Proper Motion
73.788 mas/yr
PM Right Ascension
51.78 mas/yr
PM Declination
-52.57 mas/yr
Galactic Cartesian (pc)
x = 0.570 · y = -0.812 · z = -0.129
Equatorial (J2000)
RA 305.06555° · Dec -7.41192°
Galactic ℓ, b
36.428° · -23.102°
Ecliptic λ, β
305.588° · 11.800°
HTM-20 index
1269008671
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