Key parameters at a glance
- A radius of 11.43 Earth radii
- A mass of 197.05 Earth masses
- Surface gravity around 1.51 g
- An orbital period of 3.040 days
- Semi-major axis 0.0400 AU
- Equilibrium temperature 1,092 K (819 °C)
- Distance from Earth 649.61 light-years
- Earth Similarity Index 0.132
- Travel time at Voyager 1 speed 11,455,954 years
HAT-P-27 b Planet Profile
Physical Specs
Classification
Planet Type
Gas Giant
Discovery
Size rank in cohort
Rank by radius
#1600of 1771
top 90.3%
This planet
11.43R⊕
Gas Giant median
13.52R⊕
Nearest-size peers
| Metric | Earth | HAT-P-27 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 11.43 | 11.21 |
| Mass (M⊕) | 1.00 | 197.05 | 317.83 |
| Density (g/cm³) | 5.51 | 0.76 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.51 | 2.53 |
| Insolation (S⊕) | 1.00 | 336.04 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 197.050 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
TIC
TIC 461239485
Gaia DR2
Gaia DR2 1159336403336463872
Gaia DR3
Gaia DR3 1159336403336463872
System
HAT-P-27
Percentile among Gas Giant cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 3.04 Earth days (0.8% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0400 AU.
Transit Fingerprint
Depth
1.430 %
Duration
1.680 h
Impact parameter b
0.870
Rp / R★
0.120000
Transit midpoint (BJD)
2,455,407.9088
Photometric dip
Transit produces a flux drop of 14,300 ppm lasting ≈ 1.68 h.
Extended Orbital Architecture
Planet / star radius ratio
0.120000
Semi-major axis / stellar radius
9.804
Impact parameter (b)
0.870
RV semi-amplitude (K)
91.200 m/s
Transit mid-time (BJD)
2,455,407.9088
Long. of periastron (ω)
0.00°
Sky-projected obliquity (λ)
24.20°
Angular separation (arcsec)
0.20100
Eq. Temperature
1,092K
(819 °C)
Insolation (S⊕)
336.04
Earth = 1.00
Earth Similarity (ESI)
0.132
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
Beky et al. 2011Instrument
2K CCD Sensor
Publication
2011-06
Observation locale
Ground
Discovery cohort
Planets confirmed in 2011 at HATNet (10 shown).
Host System: HAT-P-27
Spectral Class
G-type yellow (Sun-like)
Effective Temperature
5,316 K — cooler than the Sun (5,778 K)
Estimated Age
4.40 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
0.865 R☉
Stellar Mass
0.916 M☉
Metallicity [Fe/H]
0.30
Extended Stellar Properties
Surface gravity (log g)
4.526 dex
Stellar density
1.998 g/cm³
Systemic radial velocity
-15.77 km/s
Rotational v·sin i
0.40 km/s
Metallicity ratio
[M/H]
Multi-band Host Photometry — 11 bands
Astrometric Data
Parallax
4.992 mas
Total Proper Motion
28.753 mas/yr
PM Right Ascension
-28.62 mas/yr
PM Declination
-2.76 mas/yr
Galactic Cartesian (pc)
x = -0.730 · y = -0.675 · z = 0.104
Equatorial (J2000)
RA 222.76732° · Dec 5.94736°
Galactic ℓ, b
1.683° · 54.544°
Ecliptic λ, β
218.382° · 21.328°
HTM-20 index
-1273614565
Similar Worlds
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Gas Giant · G-type yellow (Sun-like)
Radius 11.43 R⊕ · 3,836.0 ly
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TOI-564 b
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TOI-199 c
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