Key parameters at a glance
- A radius of 2.77 Earth radii
- A mass of 8.80 Earth masses
- Surface gravity around 1.15 g
- An orbital period of 3.698 days
- Semi-major axis 0.0345 AU
- Equilibrium temperature 531 K (258 °C)
- Distance from Earth 185.98 light-years
- Earth Similarity Index 0.457
- Travel time at Voyager 1 speed 3,279,798 years
- Almost certainly tidally locked to its host star given the close orbit
TOI-269 b Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#780of 1978
top 39.4%
This planet
2.77R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | TOI-269 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 2.77 | 11.21 |
| Mass (M⊕) | 1.00 | 8.80 | 317.83 |
| Density (g/cm³) | 5.51 | 2.28 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.15 | 2.53 |
| Insolation (S⊕) | 1.00 | 19.00 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 8.800 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
TIC
TIC 220479565
Gaia DR2
Gaia DR2 4770828304936109056
Gaia DR3
Gaia DR3 4770828304936109056
System
TOI-269
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 3.70 Earth days (1.0% of a terrestrial year) on a highly eccentric trajectory at a mean orbital distance of 0.0345 AU.
Transit Fingerprint
Depth
0.476 %
Duration
0.931 h
Impact parameter b
0.550
Rp / R★
0.063800
Transit midpoint (BJD)
2,458,381.8467
Photometric dip
Transit produces a flux drop of 4,756 ppm lasting ≈ 0.93 h.
Extended Orbital Architecture
Planet / star radius ratio
0.063800
Semi-major axis / stellar radius
18.530
Impact parameter (b)
0.550
RV semi-amplitude (K)
7.600 m/s
Transit mid-time (BJD)
2,458,381.8467
Long. of periastron (ω)
74.00°
Angular separation (arcsec)
0.60500
Eq. Temperature
531K
(258 °C)
Insolation (S⊕)
19.00
Earth = 1.00
Earth Similarity (ESI)
0.457
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
Cointepas et al. 2021Instrument
TESS CCD Array
Publication
2021-06
Observation locale
Space
Discovery cohort
Planets confirmed in 2021 at Transiting Exoplanet Survey Satellite (TESS) (12 shown).
Host System: TOI-269
Spectral Class
M-type red dwarf
Effective Temperature
3,514 K — cooler than the Sun (5,778 K)
Estimated Age
—
Stellar Radius
0.398 R☉
Stellar Mass
0.392 M☉
Metallicity [Fe/H]
-0.29
Extended Stellar Properties
Surface gravity (log g)
4.831 dex
Stellar density
8.980 g/cm³
Systemic radial velocity
37.23 km/s
Activity index (log R'HK)
-5.320
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 11 bands
Astrometric Data
Parallax
17.508 mas
Total Proper Motion
123.618 mas/yr
PM Right Ascension
26.47 mas/yr
PM Declination
-120.75 mas/yr
Galactic Cartesian (pc)
x = 0.143 · y = 0.568 · z = -0.811
Equatorial (J2000)
RA 75.84628° · Dec -54.17772°
Galactic ℓ, b
261.960° · -37.323°
Ecliptic λ, β
54.157° · -75.852°
HTM-20 index
-1698598065
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