Key parameters at a glance
- A radius of 9.19 Earth radii
- A mass of 27.40 Earth masses
- Surface gravity around 0.32 g
- An orbital period of 7.065 days
- Semi-major axis 0.0696 AU
- Equilibrium temperature 868 K (595 °C)
- Distance from Earth 431.68 light-years
- Earth Similarity Index 0.139
- Travel time at Voyager 1 speed 7,612,628 years
TOI-1173 b Planet Profile
Physical Specs
Classification
Planet Type
Neptune-like
Discovery
Size rank in cohort
Rank by radius
#70of 574
top 12.0%
This planet
9.19R⊕
Neptune-like median
6.39R⊕
Nearest-size peers
| Metric | Earth | TOI-1173 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 9.19 | 11.21 |
| Mass (M⊕) | 1.00 | 27.40 | 317.83 |
| Density (g/cm³) | 5.51 | 0.20 | 1.33 |
| Surface Gravity (g) | 1.00 | 0.32 | 2.53 |
| Insolation (S⊕) | 1.00 | 132.00 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 27.400 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
TIC
TIC 232967440
Gaia DR2
Gaia DR2 1686171213716517504
Gaia DR3
Gaia DR3 1686171213716517504
System
TOI-1173
Percentile among Neptune-like cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 7.06 Earth days (1.9% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0696 AU.
Transit Fingerprint
Depth
0.827 %
Duration
2.586 h
Impact parameter b
0.771
Rp / R★
0.090000
Transit midpoint (BJD)
2,458,702.8444
Photometric dip
Transit produces a flux drop of 8,268 ppm lasting ≈ 2.59 h.
Extended Orbital Architecture
Planet / star radius ratio
0.090000
Semi-major axis / stellar radius
16.020
Impact parameter (b)
0.771
RV semi-amplitude (K)
9.670 m/s
Transit mid-time (BJD)
2,458,702.8444
Long. of periastron (ω)
90.00°
Angular separation (arcsec)
0.52600
Eq. Temperature
868K
(595 °C)
Insolation (S⊕)
132.00
Earth = 1.00
Earth Similarity (ESI)
0.139
0 = alien, 1 = Earth-identical
Inside the inner HZ boundary (too hot for liquid water) — the surface is too hot to retain surface water.
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-1173
Spectral Class
G-type yellow (Sun-like)
Effective Temperature
5,350 K — cooler than the Sun (5,778 K)
Estimated Age
8.70 Gyr — older than the Sun (4.6 Gyr)
Stellar Radius
0.934 R☉
Stellar Mass
0.911 M☉
Metallicity [Fe/H]
0.14
Extended Stellar Properties
Surface gravity (log g)
4.450 dex
Stellar density
1.613 g/cm³
Rotational v·sin i
2.00 km/s
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 11 bands
Astrometric Data
Parallax
7.527 mas
Total Proper Motion
109.041 mas/yr
PM Right Ascension
57.65 mas/yr
PM Declination
-92.55 mas/yr
Galactic Cartesian (pc)
x = -0.314 · y = -0.100 · z = 0.944
Equatorial (J2000)
RA 197.68310° · Dec 70.76801°
Galactic ℓ, b
120.635° · 46.274°
Ecliptic λ, β
137.875° · 64.969°
HTM-20 index
-1953814187
Similar Worlds
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