Key parameters at a glance
- A radius of 3.03 Earth radii
- A mass of 13.80 Earth masses
- Surface gravity around 1.50 g
- An orbital period of 10.695 days
- Semi-major axis 0.0891 AU
- Equilibrium temperature 805 K (532 °C)
- Distance from Earth 295.95 light-years
- Earth Similarity Index 0.307
- Travel time at Voyager 1 speed 5,219,159 years
- Almost certainly tidally locked to its host star given the close orbit
TOI-220 b Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#491of 1978
top 24.8%
This planet
3.03R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | TOI-220 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 3.03 | 11.21 |
| Mass (M⊕) | 1.00 | 13.80 | 317.83 |
| Density (g/cm³) | 5.51 | 2.73 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.50 | 2.53 |
| Insolation (S⊕) | 1.00 | 137.73 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 13.800 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
TIC
TIC 150098860
Gaia DR2
Gaia DR2 5481210874877547904
Gaia DR3
Gaia DR3 5481210874877547904
System
TOI-220
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 10.70 Earth days (2.9% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0891 AU.
Transit Fingerprint
Depth
0.093 %
Duration
2.239 h
Impact parameter b
0.836
Rp / R★
0.032350
Transit midpoint (BJD)
2,458,335.9020
Photometric dip
Transit produces a flux drop of 928 ppm lasting ≈ 2.24 h.
Extended Orbital Architecture
Planet / star radius ratio
0.032350
Semi-major axis / stellar radius
22.330
Impact parameter (b)
0.836
RV semi-amplitude (K)
4.560 m/s
Transit mid-time (BJD)
2,458,335.9020
Long. of periastron (ω)
248.00°
Angular separation (arcsec)
0.98200
Eq. Temperature
805K
(532 °C)
Insolation (S⊕)
137.73
Earth = 1.00
Earth Similarity (ESI)
0.307
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
Hoyer et al. 2021Instrument
TESS CCD Array
Publication
2021-08
Observation locale
Space
Discovery cohort
Planets confirmed in 2021 at Transiting Exoplanet Survey Satellite (TESS) (12 shown).
Host System: TOI-220
Spectral Class
K-type orange
Effective Temperature
5,298 K — cooler than the Sun (5,778 K)
Estimated Age
10.10 Gyr — older than the Sun (4.6 Gyr)
Stellar Radius
0.858 R☉
Stellar Mass
0.825 M☉
Metallicity [Fe/H]
-0.22
Extended Stellar Properties
Surface gravity (log g)
4.370 dex
Stellar density
1.847 g/cm³
Systemic radial velocity
26.46 km/s
Rotational v·sin i
2.90 km/s
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 11 bands
Astrometric Data
Parallax
10.992 mas
Total Proper Motion
70.644 mas/yr
PM Right Ascension
-17.82 mas/yr
PM Declination
-68.36 mas/yr
Galactic Cartesian (pc)
x = -0.015 · y = 0.469 · z = -0.883
Equatorial (J2000)
RA 91.79970° · Dec -61.99721°
Galactic ℓ, b
271.185° · -28.866°
Ecliptic λ, β
100.523° · -85.371°
HTM-20 index
1299241049
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