Key parameters at a glance
- A radius of 15.33 Earth radii
- A mass of 664.24 Earth masses
- Surface gravity around 2.82 g
- An orbital period of 1.213 days
- Semi-major axis 0.0232 AU
- Equilibrium temperature 2,056 K (1783 °C)
- Distance from Earth 1,189.86 light-years
- Earth Similarity Index 0.061
- Travel time at Voyager 1 speed 20,983,171 years
HAT-P-23 b Planet Profile
Physical Specs
Classification
Planet Type
Gas Giant
Discovery
Size rank in cohort
Rank by radius
#207of 1771
top 11.6%
This planet
15.33R⊕
Gas Giant median
13.52R⊕
Nearest-size peers
| Metric | Earth | HAT-P-23 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 15.33 | 11.21 |
| Mass (M⊕) | 1.00 | 664.24 | 317.83 |
| Density (g/cm³) | 5.51 | 1.01 | 1.33 |
| Surface Gravity (g) | 1.00 | 2.82 | 2.53 |
| Insolation (S⊕) | 1.00 | 2,796.23 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 664.237 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
TIC
TIC 305243225
Gaia DR2
Gaia DR2 1808938730710633984
Gaia DR3
Gaia DR3 1808938730710633984
System
HAT-P-23
Percentile among Gas Giant cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 1.21 Earth days (0.3% of a terrestrial year) on a mildly elliptical path at a mean orbital distance of 0.0232 AU.
Transit Fingerprint
Depth
1.054 %
Duration
2.179 h
Impact parameter b
0.324
Rp / R★
0.116900
Transit midpoint (BJD)
2,454,852.2646
Photometric dip
Transit produces a flux drop of 10,536 ppm lasting ≈ 2.18 h.
Extended Orbital Architecture
Planet / star radius ratio
0.116900
Semi-major axis / stellar radius
4.140
Impact parameter (b)
0.324
RV semi-amplitude (K)
368.500 m/s
Transit mid-time (BJD)
2,454,852.2646
Long. of periastron (ω)
118.00°
Sky-projected obliquity (λ)
15.00°
Angular separation (arcsec)
0.06360
Eq. Temperature
2,056K
(1783 °C)
Insolation (S⊕)
2,796.23
Earth = 1.00
Earth Similarity (ESI)
0.061
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
Bakos et al. 2010Instrument
2K CCD Sensor
Publication
2011-12
Observation locale
Ground
Discovery cohort
Planets confirmed in 2010 at HATNet (12 shown).
Host System: HAT-P-23
Spectral Class
G-type yellow (Sun-like)
Effective Temperature
5,905 K — hotter than the Sun (5,778 K)
Estimated Age
4.00 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
1.203 R☉
Stellar Mass
1.130 M☉
Metallicity [Fe/H]
0.15
Extended Stellar Properties
Surface gravity (log g)
4.330 dex
Stellar density
1.204 g/cm³
Systemic radial velocity
-15.10 km/s
Rotational v·sin i
8.10 km/s
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 11 bands
Astrometric Data
Parallax
2.713 mas
Total Proper Motion
14.325 mas/yr
PM Right Ascension
13.26 mas/yr
PM Declination
-5.41 mas/yr
Galactic Cartesian (pc)
x = 0.564 · y = -0.773 · z = 0.288
Equatorial (J2000)
RA 306.12391° · Dec 16.76215°
Galactic ℓ, b
58.936° · -11.834°
Ecliptic λ, β
313.494° · 34.907°
HTM-20 index
-64879224
Observation Record
RV measurements
1
Transmission spectra
2
Emission spectra
6
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