Key parameters at a glance
- A radius of 2.48 Earth radii
- A mass of 19.10 Earth masses
- Surface gravity around 3.11 g
- An orbital period of 10.289 days
- Semi-major axis 0.0910 AU
- Equilibrium temperature 702 K (429 °C)
- Distance from Earth 215.10 light-years
- Earth Similarity Index 0.377
- Travel time at Voyager 1 speed 3,793,292 years
- Almost certainly tidally locked to its host star given the close orbit
1 sibling around HIP 97166
HIP 97166 b 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 |
|---|---|---|---|---|---|---|
| HIP 97166 b this | Sub-Neptune | 2.48 | 19.10 | 10.289 | 702 | 2021 |
| HIP 97166 c | Sub-Neptune | 2.75 | 8.00 | 16.432 | 642 | 2021 |
HIP 97166 b Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#1211of 1978
top 61.2%
This planet
2.48R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | HIP 97166 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 2.48 | 11.21 |
| Mass (M⊕) | 1.00 | 19.10 | 317.83 |
| Density (g/cm³) | 5.51 | 6.86 | 1.33 |
| Surface Gravity (g) | 1.00 | 3.11 | 2.53 |
| Insolation (S⊕) | 1.00 | 9.07 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 19.100 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
HIP
HIP 97166
TIC
TIC 237222864
Gaia DR2
Gaia DR2 2288221003213039488
Gaia DR3
Gaia DR3 2288221003213039488
System
HIP 97166
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 10.29 Earth days (2.8% of a terrestrial year) on a mildly elliptical path at a mean orbital distance of 0.0910 AU.
Transit Fingerprint
Depth
0.085 %
Duration
1.533 h
Impact parameter b
0.328
Rp / R★
0.027010
Transit midpoint (BJD)
2,458,691.6544
Photometric dip
Transit produces a flux drop of 854 ppm lasting ≈ 1.53 h.
Extended Orbital Architecture
Planet / star radius ratio
0.027010
Impact parameter (b)
0.328
RV semi-amplitude (K)
6.180 m/s
Transit mid-time (BJD)
2,458,691.6544
Long. of periastron (ω)
98.00°
Angular separation (arcsec)
1.38000
Eq. Temperature
702K
(429 °C)
Insolation (S⊕)
9.07
Earth = 1.00
Earth Similarity (ESI)
0.377
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.
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
Macdougall et al. 2021Instrument
TESS CCD Array
Publication
2021-12
Observation locale
Space
Discovery cohort
Planets confirmed in 2021 at Transiting Exoplanet Survey Satellite (TESS) (12 shown).
Host System: HIP 97166
Spectral Class
K-type orange
Effective Temperature
5,216 K — cooler than the Sun (5,778 K)
Estimated Age
1.20 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
0.842 R☉
Stellar Mass
0.934 M☉
Metallicity [Fe/H]
0.25
Extended Stellar Properties
Surface gravity (log g)
4.557 dex
Stellar density
2.193 g/cm³
Activity index (log R'HK)
-5.010
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 11 bands
Astrometric Data
Parallax
15.134 mas
Total Proper Motion
33.636 mas/yr
PM Right Ascension
18.62 mas/yr
PM Declination
28.01 mas/yr
Galactic Cartesian (pc)
x = 0.121 · y = -0.246 · z = 0.962
Equatorial (J2000)
RA 296.24462° · Dec 74.06286°
Galactic ℓ, b
106.132° · 22.451°
Ecliptic λ, β
52.196° · 78.574°
HTM-20 index
-997005122
Similar Worlds
K2-285 d
Sub-Neptune · K-type orange
Radius 2.48 R⊕ · 505.4 ly
Kepler-1030 b
Sub-Neptune · K-type orange
Radius 2.48 R⊕ · 2,474.6 ly
TOI-1301.01
Sub-Neptune · K-type orange
Radius 2.48 R⊕ · 296.4 ly
TOI-712 d
Sub-Neptune · K-type orange
Radius 2.47 R⊕ · 191.2 ly
Kepler-475 b
Sub-Neptune · K-type orange
Radius 2.49 R⊕ · 913.5 ly
HD 176986 d
Sub-Neptune · K-type orange
Radius 2.49 R⊕ · 90.6 ly