Key parameters at a glance
- A radius of 13.06 Earth radii
- A mass of 436.70 Earth masses
- Surface gravity around 2.56 g
- An orbital period of 3.088 days
- Semi-major axis 0.0361 AU
- Equilibrium temperature 828 K (555 °C)
- Distance from Earth 1,422.61 light-years
- Earth Similarity Index 0.180
- Travel time at Voyager 1 speed 25,087,800 years
- Almost certainly tidally locked to its host star given the close orbit
HATS-77 b Planet Profile
Physical Specs
Classification
Planet Type
Gas Giant
Discovery
Size rank in cohort
Rank by radius
#954of 1771
top 53.8%
This planet
13.06R⊕
Gas Giant median
13.52R⊕
Nearest-size peers
| Metric | Earth | HATS-77 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 13.06 | 11.21 |
| Mass (M⊕) | 1.00 | 436.70 | 317.83 |
| Density (g/cm³) | 5.51 | 1.08 | 1.33 |
| Surface Gravity (g) | 1.00 | 2.56 | 2.53 |
| Insolation (S⊕) | 1.00 | 78.37 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 436.696 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
TIC
TIC 11561667
Gaia DR2
Gaia DR2 5466556141521710592
Gaia DR3
Gaia DR3 5466556141521710592
System
HATS-77
Percentile among Gas Giant cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 3.09 Earth days (0.8% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0361 AU.
Transit Fingerprint
Depth
4.041 %
Duration
2.228 h
Impact parameter b
0.328
Rp / R★
0.186500
Transit midpoint (BJD)
2,459,136.6938
Photometric dip
Transit produces a flux drop of 40,412 ppm lasting ≈ 2.23 h.
Extended Orbital Architecture
Planet / star radius ratio
0.186500
Semi-major axis / stellar radius
12.060
Impact parameter (b)
0.328
RV semi-amplitude (K)
253.000 m/s
Transit mid-time (BJD)
2,459,136.6938
Angular separation (arcsec)
0.08270
Eq. Temperature
828K
(555 °C)
Insolation (S⊕)
78.37
Earth = 1.00
Earth Similarity (ESI)
0.180
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
Jord Aacute N et al. 2022Instrument
Apogee 4K CCD Sensor
Publication
2022-03
Observation locale
Ground
Discovery cohort
Planets confirmed in 2021 at HATSouth (3 shown).
Host System: HATS-77
Spectral Class
K-type orange
Effective Temperature
4,071 K — cooler than the Sun (5,778 K)
Estimated Age
12.10 Gyr — older than the Sun (4.6 Gyr)
Stellar Radius
0.643 R☉
Stellar Mass
0.655 M☉
Metallicity [Fe/H]
0.25
Extended Stellar Properties
Surface gravity (log g)
4.638 dex
Stellar density
3.480 g/cm³
Systemic radial velocity
-7.76 km/s
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 11 bands
Astrometric Data
Parallax
2.265 mas
Total Proper Motion
25.991 mas/yr
PM Right Ascension
-24.63 mas/yr
PM Declination
-8.29 mas/yr
Galactic Cartesian (pc)
x = -0.768 · y = 0.446 · z = -0.460
Equatorial (J2000)
RA 149.82367° · Dec -27.39282°
Galactic ℓ, b
262.269° · 21.579°
Ecliptic λ, β
163.558° · -36.845°
HTM-20 index
-113961388
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