Key parameters at a glance
- A radius of 1.28 Earth radii
- A mass of 2.22 Earth masses
- Surface gravity around 1.35 g
- An orbital period of 2.178 days
- Equilibrium temperature 1,462 K (1189 °C)
- Distance from Earth 88.22 light-years
- Earth Similarity Index 0.200
- Travel time at Voyager 1 speed 1,555,840 years
4 siblings around HD 158259
HD 158259 b shares its host star with 4 other confirmed planets. Side-by-side measurements below.
| Planet | Type | Radius (R⊕) | Mass (M⊕) | Period (d) | Eq. T (K) | Year |
|---|---|---|---|---|---|---|
| HD 158259 b this | Super-Earth | 1.28 | 2.22 | 2.178 | 1,462 | 2020 |
| HD 158259 c | Sub-Neptune | 2.23 | 5.60 | 3.432 | — | 2020 |
| HD 158259 d | Sub-Neptune | 2.18 | 5.41 | 5.198 | — | 2020 |
| HD 158259 e | Sub-Neptune | 2.34 | 6.08 | 7.951 | — | 2020 |
| HD 158259 f | Sub-Neptune | 2.35 | 6.14 | 12.028 | — | 2020 |
HD 158259 b Planet Profile
Physical Specs
Classification
Planet Type
Super-Earth
Discovery
Size rank in cohort
Rank by radius
#1116of 1176
top 94.8%
This planet
1.28R⊕
Super-Earth median
1.60R⊕
Nearest-size peers
| Metric | Earth | HD 158259 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 1.28 | 11.21 |
| Mass (M⊕) | 1.00 | 2.22 | 317.83 |
| Density (g/cm³) | 5.51 | 6.12 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.35 | 2.53 |
| Insolation (S⊕) | 1.00 | 759.18 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Minimum mass (M sin i) | 2.220 M⊕ | Lower bound from radial-velocity fitting. |
Star Catalogue Identifiers
HD
HD 158259
HIP
HIP 85268
TIC
TIC 188768068
Gaia DR2
Gaia DR2 1416050859226670848
Gaia DR3
Gaia DR3 1416050859226670848
System
HD 158259
Percentile among Super-Earth cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 2.18 Earth days (0.6% of a terrestrial year).
Transit Fingerprint
Depth
0.011 %
Duration
2.098 h
Transit midpoint (BJD)
2,460,338.5231
Photometric dip
Transit produces a flux drop of 110 ppm lasting ≈ 2.10 h.
Eq. Temperature
1,462K
(1189 °C)
Insolation (S⊕)
759.18
Earth = 1.00
Earth Similarity (ESI)
0.200
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
Hara et al. 2020Instrument
SOPHIE Spectrograph
Publication
2020-04
Observation locale
Ground
Discovery cohort
Planets confirmed in 2020 at Haute-Provence Observatory (6 shown).
Host System: HD 158259
Spectral Class
G-type yellow (Sun-like)
Effective Temperature
5,802 K — hotter than the Sun (5,778 K)
Estimated Age
—
Stellar Radius
1.210 R☉
Stellar Mass
1.080 M☉
Metallicity [Fe/H]
—
Extended Stellar Properties
Surface gravity (log g)
4.251 dex
Stellar density
0.725 g/cm³
Systemic radial velocity
13.30 km/s
Rotational v·sin i
2.90 km/s
Rotation period
20.00 days
Multi-band Host Photometry — 11 bands
Astrometric Data
Parallax
36.940 mas
Total Proper Motion
103.699 mas/yr
PM Right Ascension
-91.05 mas/yr
PM Declination
-49.64 mas/yr
Galactic Cartesian (pc)
x = -0.091 · y = -0.598 · z = 0.796
Equatorial (J2000)
RA 261.34958° · Dec 52.79047°
Galactic ℓ, b
80.138° · 34.090°
Ecliptic λ, β
248.565° · 75.586°
HTM-20 index
1025354342
Similar Worlds
K2-407 b
Super-Earth · G-type yellow (Sun-like)
Radius 1.28 R⊕ · 712.2 ly
K2-158 c
Super-Earth · G-type yellow (Sun-like)
Radius 1.28 R⊕ · 643.5 ly
Kepler-1357 b
Super-Earth · G-type yellow (Sun-like)
Radius 1.28 R⊕ · 3,312.7 ly
Kepler-1693 b
Super-Earth · G-type yellow (Sun-like)
Radius 1.29 R⊕ · 2,479.0 ly
Kepler-1415 b
Super-Earth · G-type yellow (Sun-like)
Radius 1.29 R⊕ · 3,403.6 ly
Kepler-1012 b
Super-Earth · G-type yellow (Sun-like)
Radius 1.29 R⊕ · 1,340.8 ly