Key parameters at a glance
- A radius of 9.08 Earth radii
- A mass of 54.03 Earth masses
- Surface gravity around 0.66 g
- An orbital period of 104.854 days
- Semi-major axis 0.4254 AU
- Equilibrium temperature 476 K (203 °C)
- Distance from Earth 333.56 light-years
- Earth Similarity Index 0.285
- Travel time at Voyager 1 speed 5,882,326 years
1 sibling around TOI-199
TOI-199 b shares its host star with 1 other confirmed planet. Side-by-side measurements below.
| Planet | Type | Radius (R⊕) | Mass (M⊕) | Period (d) | Eq. T (K) | Year |
|---|---|---|---|---|---|---|
| TOI-199 b this | Neptune-like | 9.08 | 54.03 | 104.854 | 476 | 2023 |
| TOI-199 c | Gas Giant | 11.40 | 88.99 | 273.690 | — | 2023 |
TOI-199 b Planet Profile
Physical Specs
Classification
Planet Type
Neptune-like
Discovery
Size rank in cohort
Rank by radius
#82of 574
top 14.1%
This planet
9.08R⊕
Neptune-like median
6.39R⊕
Nearest-size peers
| Metric | Earth | TOI-199 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 9.08 | 11.21 |
| Mass (M⊕) | 1.00 | 54.03 | 317.83 |
| Density (g/cm³) | 5.51 | 0.40 | 1.33 |
| Surface Gravity (g) | 1.00 | 0.66 | 2.53 |
| Insolation (S⊕) | 1.00 | 8.54 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 54.031 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
TIC
TIC 309792357
Gaia DR2
Gaia DR2 4762582895440787712
Gaia DR3
Gaia DR3 4762582895440787712
System
TOI-199
Percentile among Neptune-like cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 104.85 Earth days (28.7% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.4254 AU.
Transit Fingerprint
Depth
1.185 %
Duration
6.689 h
Impact parameter b
0.450
Transit midpoint (BJD)
2,458,256.1286
Photometric dip
Transit produces a flux drop of 11,850 ppm lasting ≈ 6.69 h.
Extended Orbital Architecture
Impact parameter (b)
0.450
RV semi-amplitude (K)
7.700 m/s
Transit mid-time (BJD)
2,458,256.1286
Long. of periastron (ω)
350.00°
Angular separation (arcsec)
4.16000
Eq. Temperature
476K
(203 °C)
Insolation (S⊕)
8.54
Earth = 1.00
Earth Similarity (ESI)
0.285
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.
Transit timing variations
Gravitational interactions from neighbours have been detected.
Discovery Paper
Primary reference
Hobson et al. 2023Instrument
TESS CCD Array
Publication
2023-09
Observation locale
Space
Discovery cohort
Planets confirmed in 2023 at Transiting Exoplanet Survey Satellite (TESS) (12 shown).
Host System: TOI-199
Spectral Class
G-type yellow (Sun-like)
Effective Temperature
5,255 K — cooler than the Sun (5,778 K)
Estimated Age
0.80 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
0.820 R☉
Stellar Mass
0.936 M☉
Metallicity [Fe/H]
0.22
Extended Stellar Properties
Surface gravity (log g)
4.582 dex
Stellar density
2.390 g/cm³
Rotational v·sin i
0.50 km/s
Activity index (log R'HK)
-4.770
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 11 bands
Astrometric Data
Parallax
9.749 mas
Total Proper Motion
74.200 mas/yr
PM Right Ascension
45.70 mas/yr
PM Declination
58.45 mas/yr
Galactic Cartesian (pc)
x = 0.086 · y = 0.494 · z = -0.865
Equatorial (J2000)
RA 80.10587° · Dec -59.89543°
Galactic ℓ, b
268.766° · -34.550°
Ecliptic λ, β
51.720° · -82.002°
HTM-20 index
1232827602
Similar Worlds
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Kepler-950 b
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