Key parameters at a glance
- A radius of 7.54 Earth radii
- A mass of 67.40 Earth masses
- Surface gravity around 1.19 g
- An orbital period of 38.800 days
- Semi-major axis 0.2120 AU
- Equilibrium temperature 424 K (150 °C)
- Distance from Earth 233.68 light-years
- Earth Similarity Index 0.378
- Travel time at Voyager 1 speed 4,120,883 years
- Almost certainly tidally locked to its host star given the close orbit
TOI-1823 b Planet Profile
Physical Specs
Classification
Planet Type
Neptune-like
Discovery
Size rank in cohort
Rank by radius
#177of 574
top 30.7%
This planet
7.54R⊕
Neptune-like median
6.39R⊕
Nearest-size peers
| Metric | Earth | TOI-1823 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 7.54 | 11.21 |
| Mass (M⊕) | 1.00 | 67.40 | 317.83 |
| Density (g/cm³) | 5.51 | 0.86 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.19 | 2.53 |
| Insolation (S⊕) | 1.00 | 9.30 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 67.400 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
TIC
TIC 142381532
Gaia DR2
Gaia DR2 1676299557803904000
Gaia DR3
Gaia DR3 1676299557803904000
System
TOI-1823
Percentile among Neptune-like cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 38.80 Earth days (10.6% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.2120 AU.
Transit Fingerprint
Depth
0.959 %
Duration
5.923 h
Impact parameter b
0.186
Rp / R★
0.085892
Transit midpoint (BJD)
2,459,645.7050
Photometric dip
Transit produces a flux drop of 9,593 ppm lasting ≈ 5.92 h.
Extended Orbital Architecture
Planet / star radius ratio
0.085892
Impact parameter (b)
0.186
RV semi-amplitude (K)
14.400 m/s
Transit mid-time (BJD)
2,459,645.7050
Long. of periastron (ω)
74.00°
Angular separation (arcsec)
2.96000
Eq. Temperature
424K
(150 °C)
Insolation (S⊕)
9.30
Earth = 1.00
Earth Similarity (ESI)
0.378
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
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-1823
Spectral Class
K-type orange
Effective Temperature
4,927 K — cooler than the Sun (5,778 K)
Estimated Age
6.30 Gyr — older than the Sun (4.6 Gyr)
Stellar Radius
0.805 R☉
Stellar Mass
0.841 M☉
Metallicity [Fe/H]
0.24
Extended Stellar Properties
Surface gravity (log g)
4.548 dex
Stellar density
2.241 g/cm³
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 16 bands
Astrometric Data
Parallax
13.929 mas
Total Proper Motion
139.343 mas/yr
PM Right Ascension
-65.33 mas/yr
PM Declination
-123.08 mas/yr
Galactic Cartesian (pc)
x = -0.425 · y = -0.124 · z = 0.897
Equatorial (J2000)
RA 196.21972° · Dec 63.75326°
Galactic ℓ, b
120.445° · 53.310°
Ecliptic λ, β
150.172° · 60.695°
HTM-20 index
1467215312
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