Key parameters at a glance
- A radius of 4.94 Earth radii
- A mass of 40.40 Earth masses
- Surface gravity around 1.66 g
- An orbital period of 5.704 days
- Semi-major axis 0.0638 AU
- Equilibrium temperature 1,213 K (940 °C)
- Distance from Earth 927.55 light-years
- Earth Similarity Index 0.167
- Travel time at Voyager 1 speed 16,357,317 years
TOI-329 b Planet Profile
Physical Specs
Classification
Planet Type
Neptune-like
Discovery
Size rank in cohort
Rank by radius
#389of 574
top 67.6%
This planet
4.94R⊕
Neptune-like median
6.39R⊕
Nearest-size peers
| Metric | Earth | TOI-329 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 4.94 | 11.21 |
| Mass (M⊕) | 1.00 | 40.40 | 317.83 |
| Density (g/cm³) | 5.51 | 1.84 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.66 | 2.53 |
| Insolation (S⊕) | 1.00 | 576.87 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 40.400 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
TIC
TIC 169765334
Gaia DR2
Gaia DR2 2407507535105410944
Gaia DR3
Gaia DR3 2407507535105410944
System
TOI-329
Percentile among Neptune-like cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 5.70 Earth days (1.6% of a terrestrial year) on a highly eccentric trajectory at a mean orbital distance of 0.0638 AU.
Transit Fingerprint
Depth
0.094 %
Duration
4.208 h
Impact parameter b
0.465
Rp / R★
0.029554
Transit midpoint (BJD)
2,459,090.7955
Photometric dip
Transit produces a flux drop of 941 ppm lasting ≈ 4.21 h.
Extended Orbital Architecture
Planet / star radius ratio
0.029554
Impact parameter (b)
0.465
RV semi-amplitude (K)
15.100 m/s
Transit mid-time (BJD)
2,459,090.7955
Long. of periastron (ω)
170.00°
Angular separation (arcsec)
0.22400
Eq. Temperature
1,213K
(940 °C)
Insolation (S⊕)
576.87
Earth = 1.00
Earth Similarity (ESI)
0.167
0 = alien, 1 = Earth-identical
Inside the inner HZ boundary (too hot for liquid water) — the dayside is scorched.
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-329
Spectral Class
G-type yellow (Sun-like)
Effective Temperature
5,614 K — cooler than the Sun (5,778 K)
Estimated Age
8.70 Gyr — older than the Sun (4.6 Gyr)
Stellar Radius
1.533 R☉
Stellar Mass
1.068 M☉
Metallicity [Fe/H]
0.21
Extended Stellar Properties
Surface gravity (log g)
4.092 dex
Stellar density
0.413 g/cm³
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 11 bands
Astrometric Data
Parallax
3.488 mas
Total Proper Motion
52.372 mas/yr
PM Right Ascension
52.13 mas/yr
PM Declination
5.00 mas/yr
Galactic Cartesian (pc)
x = 0.952 · y = -0.145 · z = -0.270
Equatorial (J2000)
RA 351.32110° · Dec -15.63463°
Galactic ℓ, b
58.427° · -66.941°
Ecliptic λ, β
345.817° · -10.921°
HTM-20 index
-1751129463
Similar Worlds
rho CrB d
Neptune-like · G-type yellow (Sun-like)
Radius 4.94 R⊕ · 57.0 ly
TOI-1288 b
Neptune-like · G-type yellow (Sun-like)
Radius 4.97 R⊕ · 374.6 ly
TOI-5678 b
Neptune-like · G-type yellow (Sun-like)
Radius 4.91 R⊕ · 539.4 ly
Kepler-27 c
Neptune-like · G-type yellow (Sun-like)
Radius 4.90 R⊕ · 3,406.2 ly
HD 219666 b
Neptune-like · G-type yellow (Sun-like)
Radius 4.90 R⊕ · 307.1 ly
HD 16417 b
Neptune-like · G-type yellow (Sun-like)
Radius 5.00 R⊕ · 82.8 ly