Key parameters at a glance
- A radius of 11.60 Earth radii
- A mass of 3,651.85 Earth masses
- Surface gravity around 27.13 g
- An orbital period of 4.151 days
- Semi-major axis 0.0513 AU
- Equilibrium temperature 1,244 K (971 °C)
- Distance from Earth 1,229.78 light-years
- Earth Similarity Index 0.116
- Travel time at Voyager 1 speed 21,687,244 years
TOI-5261 b Planet Profile
Physical Specs
Classification
Planet Type
Gas Giant
Discovery
Size rank in cohort
Rank by radius
#1576of 1771
top 88.9%
This planet
11.60R⊕
Gas Giant median
13.52R⊕
Nearest-size peers
| Metric | Earth | TOI-5261 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 11.60 | 11.21 |
| Mass (M⊕) | 1.00 | 3,651.85 | 317.83 |
| Density (g/cm³) | 5.51 | 12.90 | 1.33 |
| Surface Gravity (g) | 1.00 | 27.13 | 2.53 |
| Insolation (S⊕) | 1.00 | 159.59 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 3,651.848 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
TIC
TIC 402828941
Gaia DR2
Gaia DR2 1816307618977868544
Gaia DR3
Gaia DR3 1816307623283205248
System
TOI-5261
Percentile among Gas Giant cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 4.15 Earth days (1.1% of a terrestrial year) on a mildly elliptical path at a mean orbital distance of 0.0513 AU.
Transit Fingerprint
Depth
1.153 %
Duration
2.359 h
Impact parameter b
0.666
Rp / R★
0.104100
Transit midpoint (BJD)
2,459,716.9310
Photometric dip
Transit produces a flux drop of 11,530 ppm lasting ≈ 2.36 h.
Extended Orbital Architecture
Planet / star radius ratio
0.104100
Semi-major axis / stellar radius
10.810
Impact parameter (b)
0.666
RV semi-amplitude (K)
1,424.000 m/s
Transit mid-time (BJD)
2,459,716.9310
Long. of periastron (ω)
32.40°
Angular separation (arcsec)
0.13600
Eq. Temperature
1,244K
(971 °C)
Insolation (S⊕)
159.59
Earth = 1.00
Earth Similarity (ESI)
0.116
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
Schulte et al. 2025Instrument
TESS CCD Array
Publication
2025-09
Observation locale
Space
Discovery cohort
Planets confirmed in 2025 at Transiting Exoplanet Survey Satellite (TESS) (12 shown).
Host System: TOI-5261
Spectral Class
G-type yellow (Sun-like)
Effective Temperature
5,790 K — hotter than the Sun (5,778 K)
Estimated Age
4.20 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
1.021 R☉
Stellar Mass
1.037 M☉
Metallicity [Fe/H]
0.25
Extended Stellar Properties
Surface gravity (log g)
4.436 dex
Stellar density
1.370 g/cm³
Rotational v·sin i
5.73 km/s
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 11 bands
Astrometric Data
Parallax
2.625 mas
Total Proper Motion
26.608 mas/yr
PM Right Ascension
-17.45 mas/yr
PM Declination
-20.09 mas/yr
Galactic Cartesian (pc)
x = 0.547 · y = -0.768 · z = 0.333
Equatorial (J2000)
RA 305.45855° · Dec 19.43585°
Galactic ℓ, b
60.854° · -9.834°
Ecliptic λ, β
313.700° · 37.650°
HTM-20 index
-652696636
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