Key parameters at a glance
- A radius of 2.93 Earth radii
- A mass of 8.91 Earth masses
- Surface gravity around 1.04 g
- An orbital period of 21.583 days
- Semi-major axis 0.1410 AU
- Equilibrium temperature 532 K (259 °C)
- Distance from Earth 148.60 light-years
- Earth Similarity Index 0.441
- Travel time at Voyager 1 speed 2,620,623 years
- Almost certainly tidally locked to its host star given the close orbit
1 sibling around HD 15906
HD 15906 c shares its host star with 1 other confirmed planet. Side-by-side measurements below.
| Planet | Type | Radius (R⊕) | Mass (M⊕) | Period (d) | Eq. T (K) | Year |
|---|---|---|---|---|---|---|
| HD 15906 b | Sub-Neptune | 2.24 | 5.65 | 10.925 | 668 | 2023 |
| HD 15906 c this | Sub-Neptune | 2.93 | 8.91 | 21.583 | 532 | 2023 |
HD 15906 c Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#585of 1978
top 29.5%
This planet
2.93R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | HD 15906 c | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 2.93 | 11.21 |
| Mass (M⊕) | 1.00 | 8.91 | 317.83 |
| Density (g/cm³) | 5.51 | 1.95 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.04 | 2.53 |
| Insolation (S⊕) | 1.00 | 13.37 | 0.037 |
Star Catalogue Identifiers
HD
HD 15906
TIC
TIC 4646810
Gaia DR2
Gaia DR2 5175239363214344960
Gaia DR3
Gaia DR3 5175239363214344960
System
HD 15906
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 21.58 Earth days (5.9% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1410 AU.
Transit Fingerprint
Depth
0.124 %
Duration
2.190 h
Impact parameter b
0.900
Rp / R★
0.035000
Transit midpoint (BJD)
2,457,430.8296
Photometric dip
Transit produces a flux drop of 1,243 ppm lasting ≈ 2.19 h.
Extended Orbital Architecture
Planet / star radius ratio
0.035000
Semi-major axis / stellar radius
39.920
Impact parameter (b)
0.900
Transit mid-time (BJD)
2,457,430.8296
Long. of periastron (ω)
247.90°
Angular separation (arcsec)
3.09000
Eq. Temperature
532K
(259 °C)
Insolation (S⊕)
13.37
Earth = 1.00
Earth Similarity (ESI)
0.441
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
Tuson et al. 2023Instrument
TESS CCD Array
Publication
2023-08
Observation locale
Space
Discovery cohort
Planets confirmed in 2023 at Transiting Exoplanet Survey Satellite (TESS) (12 shown).
Host System: HD 15906
Spectral Class
K-type orange
Effective Temperature
4,757 K — cooler than the Sun (5,778 K)
Estimated Age
—
Stellar Radius
0.762 R☉
Stellar Mass
0.790 M☉
Metallicity [Fe/H]
0.02
Extended Stellar Properties
Surface gravity (log g)
4.490 dex
Stellar density
2.583 g/cm³
Systemic radial velocity
-3.64 km/s
Rotational v·sin i
2.70 km/s
Activity index (log R'HK)
-4.694
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 11 bands
Astrometric Data
Parallax
21.919 mas
Total Proper Motion
196.028 mas/yr
PM Right Ascension
-173.03 mas/yr
PM Declination
-92.13 mas/yr
Galactic Cartesian (pc)
x = 0.772 · y = 0.609 · z = -0.180
Equatorial (J2000)
RA 38.27125° · Dec -10.35218°
Galactic ℓ, b
182.778° · -60.778°
Ecliptic λ, β
32.260° · -24.031°
HTM-20 index
747272008
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