Key parameters at a glance
- A radius of 2.19 Earth radii
- A mass of 6.37 Earth masses
- Surface gravity around 1.33 g
- An orbital period of 7.852 days
- Semi-major axis 0.0570 AU
- Equilibrium temperature 395 K (122 °C)
- Distance from Earth 108.82 light-years
- Earth Similarity Index 0.649
- Travel time at Voyager 1 speed 1,918,966 years
- Almost certainly tidally locked to its host star given the close orbit
TOI-2136 b Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#1691of 1978
top 85.4%
This planet
2.19R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | TOI-2136 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 2.19 | 11.21 |
| Mass (M⊕) | 1.00 | 6.37 | 317.83 |
| Density (g/cm³) | 5.51 | 3.34 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.33 | 2.53 |
| Insolation (S⊕) | 1.00 | 4.00 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 6.370 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
TIC
TIC 336128819
Gaia DR2
Gaia DR2 2096535783864546944
Gaia DR3
Gaia DR3 2096535783864546944
System
TOI-2136
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 7.85 Earth days (2.1% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0570 AU.
Transit Fingerprint
Depth
0.387 %
Duration
1.660 h
Impact parameter b
0.350
Rp / R★
0.059100
Transit midpoint (BJD)
2,459,017.7043
Photometric dip
Transit produces a flux drop of 3,874 ppm lasting ≈ 1.66 h.
Extended Orbital Architecture
Planet / star radius ratio
0.059100
Semi-major axis / stellar radius
35.750
Impact parameter (b)
0.350
RV semi-amplitude (K)
4.200 m/s
Transit mid-time (BJD)
2,459,017.7043
Long. of periastron (ω)
90.00°
Angular separation (arcsec)
1.71000
Eq. Temperature
395K
(122 °C)
Insolation (S⊕)
4.00
Earth = 1.00
Earth Similarity (ESI)
0.649
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.
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
Beard et al. 2022Instrument
TESS CCD Array
Publication
2022-04
Observation locale
Space
Discovery cohort
Planets confirmed in 2022 at Transiting Exoplanet Survey Satellite (TESS) (12 shown).
Host System: TOI-2136
Spectral Class
M-type red dwarf
Effective Temperature
3,342 K — cooler than the Sun (5,778 K)
Estimated Age
4.60 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
0.340 R☉
Stellar Mass
0.340 M☉
Metallicity [Fe/H]
0.03
Extended Stellar Properties
Surface gravity (log g)
4.910 dex
Stellar density
12.200 g/cm³
Systemic radial velocity
-28.80 km/s
Rotational v·sin i
2.00 km/s
Rotation period
75.00 days
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 10 bands
Astrometric Data
Parallax
29.945 mas
Total Proper Motion
180.550 mas/yr
PM Right Ascension
-33.80 mas/yr
PM Declination
177.36 mas/yr
Galactic Cartesian (pc)
x = 0.156 · y = -0.788 · z = 0.596
Equatorial (J2000)
RA 281.17634° · Dec 36.56313°
Galactic ℓ, b
65.833° · 17.015°
Ecliptic λ, β
287.759° · 59.315°
HTM-20 index
-252970442
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