Key parameters at a glance
- A radius of 2.38 Earth radii
- A mass of 8.71 Earth masses
- Surface gravity around 1.54 g
- An orbital period of 1.528 days
- Semi-major axis 0.0194 AU
- Equilibrium temperature 794 K (521 °C)
- Distance from Earth 188.37 light-years
- Earth Similarity Index 0.338
- Travel time at Voyager 1 speed 3,321,947 years
- Almost certainly tidally locked to its host star given the close orbit
TOI-654.01 Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#1374of 1978
top 69.4%
This planet
2.38R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | TOI-654.01 | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 2.38 | 11.21 |
| Mass (M⊕) | 1.00 | 8.71 | 317.83 |
| Density (g/cm³) | 5.51 | 3.59 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.54 | 2.53 |
| Insolation (S⊕) | 1.00 | 65.00 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 8.710 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
TIC
TIC 35009898
Gaia DR2
Gaia DR2 3788670679927991296
Gaia DR3
Gaia DR3 3788670679927991296
System
TOI-654
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 1.53 Earth days (0.4% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0194 AU.
Transit Fingerprint
Depth
0.289 %
Duration
1.200 h
Impact parameter b
0.290
Rp / R★
0.051000
Transit midpoint (BJD)
2,459,243.0584
Photometric dip
Transit produces a flux drop of 2,892 ppm lasting ≈ 1.20 h.
Extended Orbital Architecture
Planet / star radius ratio
0.051000
Semi-major axis / stellar radius
10.517
Impact parameter (b)
0.290
RV semi-amplitude (K)
8.620 m/s
Transit mid-time (BJD)
2,459,243.0584
Long. of periastron (ω)
0.00°
Angular separation (arcsec)
0.33700
Eq. Temperature
794K
(521 °C)
Insolation (S⊕)
65.00
Earth = 1.00
Earth Similarity (ESI)
0.338
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
Hord et al. 2024Instrument
TESS CCD Array
Publication
2024-05
Observation locale
Space
Discovery cohort
Planets confirmed in 2024 at Transiting Exoplanet Survey Satellite (TESS) (12 shown).
Host System: TOI-654
Spectral Class
M-type red dwarf
Effective Temperature
3,521 K — cooler than the Sun (5,778 K)
Estimated Age
—
Stellar Radius
0.430 R☉
Stellar Mass
0.419 M☉
Metallicity [Fe/H]
0.12
Extended Stellar Properties
Surface gravity (log g)
4.793 dex
Stellar density
7.430 g/cm³
Rotational v·sin i
3.00 km/s
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 6 bands
Astrometric Data
Parallax
17.286 mas
Total Proper Motion
283.987 mas/yr
PM Right Ascension
99.17 mas/yr
PM Declination
-266.11 mas/yr
Galactic Cartesian (pc)
x = -0.960 · y = 0.262 · z = -0.097
Equatorial (J2000)
RA 164.72455° · Dec -5.54754°
Galactic ℓ, b
258.946° · 47.482°
Ecliptic λ, β
168.108° · -11.128°
HTM-20 index
-1721084924
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