Key parameters at a glance
- A radius of 2.46 Earth radii
- A mass of 6.60 Earth masses
- Surface gravity around 1.09 g
- An orbital period of 11.071 days
- Equilibrium temperature 561 K (288 °C)
- Distance from Earth 138.31 light-years
- Earth Similarity Index 0.450
- Travel time at Voyager 1 speed 2,439,097 years
- Almost certainly tidally locked to its host star given the close orbit
TOI-139 b Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#1256of 1978
top 63.4%
This planet
2.46R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | TOI-139 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 2.46 | 11.21 |
| Mass (M⊕) | 1.00 | 6.60 | 317.83 |
| Density (g/cm³) | 5.51 | 2.45 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.09 | 2.53 |
| Insolation (S⊕) | 1.00 | 22.42 | 0.037 |
Star Catalogue Identifiers
TIC
TIC 62483237
Gaia DR2
Gaia DR2 6598814657249555328
Gaia DR3
Gaia DR3 6598814657249555328
System
TOI-139
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 11.07 Earth days (3.0% of a terrestrial year).
Transit Fingerprint
Depth
0.115 %
Duration
2.194 h
Impact parameter b
0.395
Rp / R★
0.032100
Transit midpoint (BJD)
2,458,334.8906
Photometric dip
Transit produces a flux drop of 1,150 ppm lasting ≈ 2.19 h.
Extended Orbital Architecture
Planet / star radius ratio
0.032100
Semi-major axis / stellar radius
33.159
Impact parameter (b)
0.395
Transit mid-time (BJD)
2,458,334.8906
Eq. Temperature
561K
(288 °C)
Insolation (S⊕)
22.42
Earth = 1.00
Earth Similarity (ESI)
0.450
0 = alien, 1 = Earth-identical
Inside the inner HZ boundary (too hot for liquid water) — the surface is too hot to retain surface water. Close-orbiting tidally-locked around a cool host.
Discovery Paper
Primary reference
Mistry et al. 2023Instrument
TESS CCD Array
Publication
2023-01
Observation locale
Space
Discovery cohort
Planets confirmed in 2023 at Transiting Exoplanet Survey Satellite (TESS) (12 shown).
Host System: TOI-139
Spectral Class
K-type orange
Effective Temperature
4,570 K — cooler than the Sun (5,778 K)
Estimated Age
—
Stellar Radius
0.701 R☉
Stellar Mass
0.690 M☉
Metallicity [Fe/H]
-0.24
Extended Stellar Properties
Surface gravity (log g)
4.705 dex
Stellar density
2.827 g/cm³
Metallicity ratio
[M/H]
Multi-band Host Photometry — 11 bands
Astrometric Data
Parallax
23.553 mas
Total Proper Motion
40.174 mas/yr
PM Right Ascension
26.43 mas/yr
PM Declination
-30.26 mas/yr
Galactic Cartesian (pc)
x = 0.751 · y = -0.328 · z = -0.572
Equatorial (J2000)
RA 336.40241° · Dec -34.90971°
Galactic ℓ, b
9.760° · -57.991°
Ecliptic λ, β
324.861° · -23.234°
HTM-20 index
475741139
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