Key parameters at a glance
- A radius of 3.62 Earth radii
- A mass of 6.90 Earth masses
- Surface gravity around 0.53 g
- An orbital period of 20.705 days
- Semi-major axis 0.1414 AU
- Equilibrium temperature 551 K (278 °C)
- Distance from Earth 315.14 light-years
- Earth Similarity Index 0.356
- Travel time at Voyager 1 speed 5,557,438 years
- Almost certainly tidally locked to its host star given the close orbit
TOI-1758 b Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#128of 1978
top 6.4%
This planet
3.62R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | TOI-1758 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 3.62 | 11.21 |
| Mass (M⊕) | 1.00 | 6.90 | 317.83 |
| Density (g/cm³) | 5.51 | 0.83 | 1.33 |
| Surface Gravity (g) | 1.00 | 0.53 | 2.53 |
| Insolation (S⊕) | 1.00 | 21.05 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 6.900 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
TIC
TIC 367858035
Gaia DR2
Gaia DR2 2232494455384800768
Gaia DR3
Gaia DR3 2232494455385669760
System
TOI-1758
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 20.71 Earth days (5.7% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1414 AU.
Transit Fingerprint
Depth
0.182 %
Duration
3.673 h
Impact parameter b
0.515
Rp / R★
0.040600
Transit midpoint (BJD)
2,459,924.7718
Photometric dip
Transit produces a flux drop of 1,822 ppm lasting ≈ 3.67 h.
Extended Orbital Architecture
Planet / star radius ratio
0.040600
Impact parameter (b)
0.515
RV semi-amplitude (K)
1.800 m/s
Transit mid-time (BJD)
2,459,924.7718
Long. of periastron (ω)
90.00°
Angular separation (arcsec)
1.46000
Eq. Temperature
551K
(278 °C)
Insolation (S⊕)
21.05
Earth = 1.00
Earth Similarity (ESI)
0.356
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
Polanski et al. 2024Instrument
TESS CCD Array
Publication
2024-06
Observation locale
Space
Discovery cohort
Planets confirmed in 2024 at Transiting Exoplanet Survey Satellite (TESS) (12 shown).
Host System: TOI-1758
Spectral Class
K-type orange
Effective Temperature
5,169 K — cooler than the Sun (5,778 K)
Estimated Age
7.50 Gyr — older than the Sun (4.6 Gyr)
Stellar Radius
0.810 R☉
Stellar Mass
0.880 M☉
Metallicity [Fe/H]
-0.02
Extended Stellar Properties
Surface gravity (log g)
4.530 dex
Stellar density
2.127 g/cm³
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 11 bands
Astrometric Data
Parallax
10.321 mas
Total Proper Motion
86.387 mas/yr
PM Right Ascension
-82.64 mas/yr
PM Declination
25.16 mas/yr
Galactic Cartesian (pc)
x = 0.246 · y = -0.023 · z = 0.969
Equatorial (J2000)
RA 354.74158° · Dec 75.68523°
Galactic ℓ, b
118.398° · 13.455°
Ecliptic λ, β
55.968° · 63.898°
HTM-20 index
-1340006438
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