Key parameters at a glance
- A radius of 13.60 Earth radii
- A mass of 171.63 Earth masses
- Surface gravity around 0.93 g
- An orbital period of 2.044 days
- Semi-major axis 0.0325 AU
- Equilibrium temperature 1,544 K (1271 °C)
- Distance from Earth 1,025.57 light-years
- Earth Similarity Index 0.075
- Travel time at Voyager 1 speed 18,086,009 years
TOI-3856 b Planet Profile
Physical Specs
Classification
Planet Type
Gas Giant
Discovery
Size rank in cohort
Rank by radius
#655of 1771
top 36.9%
This planet
13.60R⊕
Gas Giant median
13.52R⊕
Nearest-size peers
| Metric | Earth | TOI-3856 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 13.60 | 11.21 |
| Mass (M⊕) | 1.00 | 171.63 | 317.83 |
| Density (g/cm³) | 5.51 | 0.37 | 1.33 |
| Surface Gravity (g) | 1.00 | 0.93 | 2.53 |
| Insolation (S⊕) | 1.00 | 949.00 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 171.627 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
TIC
TIC 125552076
Gaia DR2
Gaia DR2 647864446160474624
Gaia DR3
Gaia DR3 647864446160474624
System
TOI-3856
Percentile among Gas Giant cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 2.04 Earth days (0.6% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0325 AU.
Transit Fingerprint
Depth
1.397 %
Duration
1.825 h
Impact parameter b
0.814
Transit midpoint (BJD)
2,459,574.6633
Photometric dip
Transit produces a flux drop of 13,970 ppm lasting ≈ 1.83 h.
Extended Orbital Architecture
Semi-major axis / stellar radius
6.622
Impact parameter (b)
0.814
RV semi-amplitude (K)
80.000 m/s
Transit mid-time (BJD)
2,459,574.6633
Angular separation (arcsec)
0.10300
Eq. Temperature
1,544K
(1271 °C)
Insolation (S⊕)
949.00
Earth = 1.00
Earth Similarity (ESI)
0.075
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
Yee et al. 2025Instrument
TESS CCD Array
Publication
2025-07
Observation locale
Space
Discovery cohort
Planets confirmed in 2025 at Transiting Exoplanet Survey Satellite (TESS) (12 shown).
Host System: TOI-3856
Spectral Class
G-type yellow (Sun-like)
Effective Temperature
5,622 K — cooler than the Sun (5,778 K)
Estimated Age
2.60 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
1.055 R☉
Stellar Mass
1.096 M☉
Metallicity [Fe/H]
0.45
Extended Stellar Properties
Surface gravity (log g)
4.431 dex
Stellar density
1.314 g/cm³
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 16 bands
Astrometric Data
Parallax
3.152 mas
Total Proper Motion
21.702 mas/yr
PM Right Ascension
-20.97 mas/yr
PM Declination
-5.58 mas/yr
Galactic Cartesian (pc)
x = -0.726 · y = 0.504 · z = 0.469
Equatorial (J2000)
RA 145.22292° · Dec 27.95016°
Galactic ℓ, b
200.346° · 48.028°
Ecliptic λ, β
138.197° · 13.274°
HTM-20 index
1441849054
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