Key parameters at a glance
- A radius of 19.50 Earth radii
- A mass of 448.14 Earth masses
- Surface gravity around 1.18 g
- An orbital period of 2.465 days
- Semi-major axis 0.0406 AU
- Equilibrium temperature 2,200 K (1927 °C)
- Distance from Earth 912.78 light-years
- Earth Similarity Index 0.043
- Travel time at Voyager 1 speed 16,096,878 years
HAT-P-57 b Planet Profile
Physical Specs
Classification
Planet Type
Gas Giant
Discovery
Size rank in cohort
Rank by radius
#39of 1771
top 2.1%
This planet
19.50R⊕
Gas Giant median
13.52R⊕
Nearest-size peers
| Metric | Earth | HAT-P-57 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 19.50 | 11.21 |
| Mass (M⊕) | 1.00 | 448.14 | 317.83 |
| Density (g/cm³) | 5.51 | 0.33 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.18 | 2.53 |
| Insolation (S⊕) | 1.00 | 2,726.63 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 448.140 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
TIC
TIC 317520667
Gaia DR2
Gaia DR2 4483640815570090368
Gaia DR3
Gaia DR3 4483640815570090368
System
HAT-P-57
Percentile among Gas Giant cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 2.47 Earth days (0.7% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0406 AU.
Transit Fingerprint
Depth
0.940 %
Duration
3.499 h
Impact parameter b
0.177
Rp / R★
0.096800
Transit midpoint (BJD)
2,457,598.4993
Photometric dip
Transit produces a flux drop of 9,400 ppm lasting ≈ 3.50 h.
Extended Orbital Architecture
Planet / star radius ratio
0.096800
Semi-major axis / stellar radius
5.820
Impact parameter (b)
0.177
RV semi-amplitude (K)
215.200 m/s
Transit mid-time (BJD)
2,457,598.4993
Angular separation (arcsec)
0.14500
Eq. Temperature
2,200K
(1927 °C)
Insolation (S⊕)
2,726.63
Earth = 1.00
Earth Similarity (ESI)
0.043
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
Hartman et al. 2015Instrument
Multiple Instruments
Publication
2015-12
Observation locale
Ground
Discovery cohort
Planets confirmed in 2015 at HATNet (7 shown).
Host System: HAT-P-57
Spectral Class
A-type white
Effective Temperature
6,330 K — hotter than the Sun (5,778 K)
Estimated Age
1.00 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
1.850 R☉
Stellar Mass
2.770 M☉
Metallicity [Fe/H]
-0.25
Extended Stellar Properties
Surface gravity (log g)
4.250 dex
Stellar density
0.620 g/cm³
Systemic radial velocity
-5.99 km/s
Rotational v·sin i
102.10 km/s
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 15 bands
Astrometric Data
Parallax
3.545 mas
Total Proper Motion
14.875 mas/yr
PM Right Ascension
-4.60 mas/yr
PM Declination
-14.15 mas/yr
Galactic Cartesian (pc)
x = 0.081 · y = -0.980 · z = 0.184
Equatorial (J2000)
RA 274.74342° · Dec 10.59720°
Galactic ℓ, b
38.822° · 11.968°
Ecliptic λ, β
275.619° · 33.944°
HTM-20 index
-1081619763
Similar Worlds
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Gas Giant · A-type white
Radius 19.51 R⊕ · 445.0 ly
WASP-178 b
Gas Giant · A-type white
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bet Pic b
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WASP-189 b
Gas Giant · A-type white
Radius 18.15 R⊕ · 325.3 ly
HAT-P-70 b
Gas Giant · A-type white
Radius 20.96 R⊕ · 1,078.7 ly
MASCARA-1 b
Gas Giant · A-type white
Radius 17.90 R⊕ · 594.5 ly