Key parameters at a glance
- A radius of 2.93 Earth radii
- A mass of 18.47 Earth masses
- Surface gravity around 2.16 g
- An orbital period of 1.393 days
- Semi-major axis 0.0218 AU
- Equilibrium temperature 1,253 K (980 °C)
- Distance from Earth 208.50 light-years
- Earth Similarity Index 0.199
- Travel time at Voyager 1 speed 3,676,882 years
- Almost certainly tidally locked to its host star given the close orbit
TOI-824 b Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#597of 1978
top 30.1%
This planet
2.93R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | TOI-824 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 2.93 | 11.21 |
| Mass (M⊕) | 1.00 | 18.47 | 317.83 |
| Density (g/cm³) | 5.51 | 4.03 | 1.33 |
| Surface Gravity (g) | 1.00 | 2.16 | 2.53 |
| Insolation (S⊕) | 1.00 | 412.00 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 18.467 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
TIC
TIC 193641523
Gaia DR2
Gaia DR2 5880886001621564928
Gaia DR3
Gaia DR3 5880886001621564928
System
TOI-824
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 1.39 Earth days (0.4% of a terrestrial year) at a mean orbital distance of 0.0218 AU.
Transit Fingerprint
Depth
0.149 %
Duration
1.153 h
Impact parameter b
0.745
Rp / R★
0.038700
Transit midpoint (BJD)
2,458,639.6035
Photometric dip
Transit produces a flux drop of 1,490 ppm lasting ≈ 1.15 h.
Extended Orbital Architecture
Planet / star radius ratio
0.038700
Semi-major axis / stellar radius
6.730
Impact parameter (b)
0.745
RV semi-amplitude (K)
13.200 m/s
Transit mid-time (BJD)
2,458,639.6035
Angular separation (arcsec)
0.34100
Eq. Temperature
1,253K
(980 °C)
Insolation (S⊕)
412.00
Earth = 1.00
Earth Similarity (ESI)
0.199
0 = alien, 1 = Earth-identical
Inside the inner HZ boundary (too hot for liquid water) — the dayside is scorched. 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
Burt et al. 2020Instrument
TESS CCD Array
Publication
2020-10
Observation locale
Space
Discovery cohort
Planets confirmed in 2020 at Transiting Exoplanet Survey Satellite (TESS) (12 shown).
Host System: TOI-824
Spectral Class
K-type orange
Effective Temperature
4,600 K — cooler than the Sun (5,778 K)
Estimated Age
7.50 Gyr — older than the Sun (4.6 Gyr)
Stellar Radius
0.695 R☉
Stellar Mass
0.710 M☉
Metallicity [Fe/H]
-0.09
Extended Stellar Properties
Surface gravity (log g)
4.605 dex
Stellar density
2.980 g/cm³
Systemic radial velocity
29.33 km/s
Rotational v·sin i
2.17 km/s
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 13 bands
Astrometric Data
Parallax
15.614 mas
Total Proper Motion
160.892 mas/yr
PM Right Ascension
-51.60 mas/yr
PM Declination
-152.39 mas/yr
Galactic Cartesian (pc)
x = -0.397 · y = -0.360 · z = -0.844
Equatorial (J2000)
RA 222.16547° · Dec -57.58887°
Galactic ℓ, b
318.149° · 1.778°
Ecliptic λ, β
239.176° · -39.157°
HTM-20 index
1644207211
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