Key parameters at a glance
- A radius of 4.91 Earth radii
- A mass of 20.00 Earth masses
- Surface gravity around 0.83 g
- An orbital period of 47.730 days
- Semi-major axis 0.2490 AU
- Equilibrium temperature 513 K (240 °C)
- Distance from Earth 539.44 light-years
- Earth Similarity Index 0.361
- Travel time at Voyager 1 speed 9,513,010 years
TOI-5678 b Planet Profile
Physical Specs
Classification
Planet Type
Neptune-like
Discovery
Size rank in cohort
Rank by radius
#397of 574
top 69.0%
This planet
4.91R⊕
Neptune-like median
6.39R⊕
Nearest-size peers
| Metric | Earth | TOI-5678 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 4.91 | 11.21 |
| Mass (M⊕) | 1.00 | 20.00 | 317.83 |
| Density (g/cm³) | 5.51 | 0.93 | 1.33 |
| Surface Gravity (g) | 1.00 | 0.83 | 2.53 |
| Insolation (S⊕) | 1.00 | 3.84 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 20.000 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
TIC
TIC 209464063
Gaia DR2
Gaia DR2 5048310370810634624
Gaia DR3
Gaia DR3 5048310370810634624
System
TOI-5678
Percentile among Neptune-like cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 47.73 Earth days (13.1% of a terrestrial year) on a mildly elliptical path at a mean orbital distance of 0.2490 AU.
Transit Fingerprint
Depth
0.240 %
Duration
6.960 h
Impact parameter b
0.170
Rp / R★
0.048000
Transit midpoint (BJD)
2,458,424.7059
Photometric dip
Transit produces a flux drop of 2,400 ppm lasting ≈ 6.96 h.
Extended Orbital Architecture
Planet / star radius ratio
0.048000
Impact parameter (b)
0.170
RV semi-amplitude (K)
3.800 m/s
Transit mid-time (BJD)
2,458,424.7059
Long. of periastron (ω)
208.00°
Angular separation (arcsec)
1.51000
Eq. Temperature
513K
(240 °C)
Insolation (S⊕)
3.84
Earth = 1.00
Earth Similarity (ESI)
0.361
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
Ulmer Moll et al. 2023Instrument
TESS CCD Array
Publication
2023-06
Observation locale
Space
Discovery cohort
Planets confirmed in 2023 at Transiting Exoplanet Survey Satellite (TESS) (12 shown).
Host System: TOI-5678
Spectral Class
G-type yellow (Sun-like)
Effective Temperature
5,485 K — cooler than the Sun (5,778 K)
Estimated Age
8.50 Gyr — older than the Sun (4.6 Gyr)
Stellar Radius
0.938 R☉
Stellar Mass
0.905 M☉
Metallicity [Fe/H]
0.00
Extended Stellar Properties
Surface gravity (log g)
4.340 dex
Stellar density
1.551 g/cm³
Rotational v·sin i
3.10 km/s
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 11 bands
Astrometric Data
Parallax
6.017 mas
Total Proper Motion
89.320 mas/yr
PM Right Ascension
-5.57 mas/yr
PM Declination
-89.15 mas/yr
Galactic Cartesian (pc)
x = 0.560 · y = 0.609 · z = -0.562
Equatorial (J2000)
RA 47.38419° · Dec -34.19848°
Galactic ℓ, b
234.944° · -59.627°
Ecliptic λ, β
30.874° · -49.270°
HTM-20 index
-1098475732
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