Key parameters at a glance
- A radius of 2.22 Earth radii
- A mass of 5.57 Earth masses
- Surface gravity around 1.13 g
- An orbital period of 5.091 days
- Semi-major axis 0.0510 AU
- Equilibrium temperature 573 K (300 °C)
- Distance from Earth 44.34 light-years
- Earth Similarity Index 0.459
- Travel time at Voyager 1 speed 781,986 years
- Almost certainly tidally locked to its host star given the close orbit
Context from the literature
Gliese 146 is a star with an orbiting exoplanet in the constellation Horologium. Gliese 146 is also catalogued as HD 22496, HIP 16711, SAO-216392, and LHS 1563. With an apparent visual magnitude of 8.64, it is too faint to be visible to the naked eye. Gliese 146 is located at a distance of 44.4 light years based on parallax measurements, and is drifting further away with a heliocentric radial velocity of +21 km/s.
Excerpted from Wikipedia · full article
HD 22496 b Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#1642of 1978
top 83.0%
This planet
2.22R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | HD 22496 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 2.22 | 11.21 |
| Mass (M⊕) | 1.00 | 5.57 | 317.83 |
| Density (g/cm³) | 5.51 | 2.80 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.13 | 2.53 |
| Insolation (S⊕) | 1.00 | 26.00 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Minimum mass (M sin i) | 5.570 M⊕ | Lower bound from radial-velocity fitting. |
Star Catalogue Identifiers
HD
HD 22496
HIP
HIP 16711
TIC
TIC 200851505
Gaia DR2
Gaia DR2 4833654227548585856
Gaia DR3
Gaia DR3 4833654227548585856
System
HD 22496
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 5.09 Earth days (1.4% of a terrestrial year) at a mean orbital distance of 0.0510 AU.
Extended Orbital Architecture
Semi-major axis / stellar radius
24.300
RV semi-amplitude (K)
2.620 m/s
Transit mid-time (BJD)
2,458,602.5600
Angular separation (arcsec)
3.75000
Eq. Temperature
573K
(300 °C)
Insolation (S⊕)
26.00
Earth = 1.00
Earth Similarity (ESI)
0.459
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.
Discovery Paper
Primary reference
Lillo Box et al. 2021Instrument
ESPRESSO
Publication
2021-10
Observation locale
Ground
Discovery cohort
Planets confirmed in 2021 at Paranal Observatory (3 shown).
Host System: HD 22496
Spectral Class
K-type orange
Effective Temperature
4,385 K — cooler than the Sun (5,778 K)
Estimated Age
—
Stellar Radius
0.674 R☉
Stellar Mass
0.684 M☉
Metallicity [Fe/H]
-0.08
Extended Stellar Properties
Surface gravity (log g)
4.690 dex
Stellar density
2.380 g/cm³
Systemic radial velocity
21.44 km/s
Rotation period
30.00 days
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 8 bands
Astrometric Data
Parallax
73.524 mas
Total Proper Motion
507.994 mas/yr
PM Right Ascension
404.45 mas/yr
PM Declination
307.37 mas/yr
Galactic Cartesian (pc)
x = 0.392 · y = 0.535 · z = -0.748
Equatorial (J2000)
RA 53.75654° · Dec -48.41782°
Galactic ℓ, b
258.092° · -51.959°
Ecliptic λ, β
26.254° · -64.053°
HTM-20 index
2057264939
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