Key parameters at a glance
- A radius of 15.40 Earth radii
- A mass of 878.00 Earth masses
- Surface gravity around 3.70 g
- An orbital period of 4.634 days
- Semi-major axis 0.0600 AU
- Equilibrium temperature 1,561 K (1288 °C)
- Distance from Earth 527.53 light-years
- Earth Similarity Index 0.087
- Travel time at Voyager 1 speed 9,303,070 years
TOI-778 b Planet Profile
Physical Specs
Classification
Planet Type
Gas Giant
Discovery
Size rank in cohort
Rank by radius
#205of 1771
top 11.5%
This planet
15.40R⊕
Gas Giant median
13.52R⊕
Nearest-size peers
| Metric | Earth | TOI-778 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 15.40 | 11.21 |
| Mass (M⊕) | 1.00 | 878.00 | 317.83 |
| Density (g/cm³) | 5.51 | 1.30 | 1.33 |
| Surface Gravity (g) | 1.00 | 3.70 | 2.53 |
| Insolation (S⊕) | 1.00 | 734.67 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 878.000 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
HD
HD 115447
TIC
TIC 335630746
Gaia DR2
Gaia DR2 3607877948613218304
Gaia DR3
Gaia DR3 3607877948613218304
System
TOI-778
Percentile among Gas Giant cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 4.63 Earth days (1.3% of a terrestrial year) on a mildly elliptical path at a mean orbital distance of 0.0600 AU.
Transit Fingerprint
Depth
0.766 %
Duration
3.760 h
Impact parameter b
0.610
Rp / R★
0.082500
Transit midpoint (BJD)
2,458,578.7161
Photometric dip
Transit produces a flux drop of 7,660 ppm lasting ≈ 3.76 h.
Extended Orbital Architecture
Planet / star radius ratio
0.082500
Semi-major axis / stellar radius
7.600
Impact parameter (b)
0.610
RV semi-amplitude (K)
271.000 m/s
Transit mid-time (BJD)
2,458,578.7161
Long. of periastron (ω)
28.00°
Sky-projected obliquity (λ)
18.00°
Angular separation (arcsec)
0.37100
Eq. Temperature
1,561K
(1288 °C)
Insolation (S⊕)
734.67
Earth = 1.00
Earth Similarity (ESI)
0.087
0 = alien, 1 = Earth-identical
Inside the inner HZ boundary (too hot for liquid water) — the dayside is scorched.
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
Clark et al. 2023Instrument
TESS CCD Array
Publication
2023-05
Observation locale
Space
Discovery cohort
Planets confirmed in 2023 at Transiting Exoplanet Survey Satellite (TESS) (12 shown).
Host System: TOI-778
Spectral Class
F-type yellow-white
Effective Temperature
6,643 K — hotter than the Sun (5,778 K)
Estimated Age
1.95 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
1.710 R☉
Stellar Mass
1.400 M☉
Metallicity [Fe/H]
0.00
Extended Stellar Properties
Surface gravity (log g)
4.050 dex
Stellar density
0.380 g/cm³
Rotational v·sin i
39.90 km/s
Rotation period
2.58 days
Metallicity ratio
[M/H]
Multi-band Host Photometry — 11 bands
Astrometric Data
Parallax
6.154 mas
Total Proper Motion
65.947 mas/yr
PM Right Ascension
-60.60 mas/yr
PM Declination
-26.01 mas/yr
Galactic Cartesian (pc)
x = -0.910 · y = -0.319 · z = -0.263
Equatorial (J2000)
RA 199.33385° · Dec -15.27370°
Galactic ℓ, b
312.133° · 47.135°
Ecliptic λ, β
203.602° · -6.584°
HTM-20 index
-1380114223
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