Key parameters at a glance
- A radius of 2.58 Earth radii
- A mass of 9.20 Earth masses
- Surface gravity around 1.38 g
- An orbital period of 7.496 days
- Semi-major axis 0.0762 AU
- Equilibrium temperature 968 K (695 °C)
- Distance from Earth 877.96 light-years
- Earth Similarity Index 0.262
- Travel time at Voyager 1 speed 15,482,762 years
1 sibling around K2-73
K2-73 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 |
|---|---|---|---|---|---|---|
| K2-73 b this | Sub-Neptune | 2.58 | 9.20 | 7.496 | 968 | 2016 |
| K2-73 c | Gas Giant | 13.00 | 1,142.00 | 1,000.000 | 186 | 2025 |
K2-73 b Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#1057of 1978
top 53.4%
This planet
2.58R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | K2-73 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 2.58 | 11.21 |
| Mass (M⊕) | 1.00 | 9.20 | 317.83 |
| Density (g/cm³) | 5.51 | 2.80 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.38 | 2.53 |
| Insolation (S⊕) | 1.00 | 209.00 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 9.200 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
TIC
TIC 38354061
Gaia DR2
Gaia DR2 2616071555020488960
Gaia DR3
Gaia DR3 2616071555020488960
System
K2-73
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 7.50 Earth days (2.1% of a terrestrial year) at a mean orbital distance of 0.0762 AU.
Transit Fingerprint
Depth
0.058 %
Duration
3.590 h
Impact parameter b
0.280
Rp / R★
0.022901
Transit midpoint (BJD)
2,456,987.6726
Photometric dip
Transit produces a flux drop of 580 ppm lasting ≈ 3.59 h.
Extended Orbital Architecture
Planet / star radius ratio
0.022901
Semi-major axis / stellar radius
15.108
Impact parameter (b)
0.280
Transit mid-time (BJD)
2,456,987.6726
Angular separation (arcsec)
0.28300
Eq. Temperature
968K
(695 °C)
Insolation (S⊕)
209.00
Earth = 1.00
Earth Similarity (ESI)
0.262
0 = alien, 1 = Earth-identical
Inside the inner HZ boundary (too hot for liquid water) — the surface is too hot to retain surface water.
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
Crossfield et al. 2016Instrument
Kepler CCD Array
Publication
2016-09
Observation locale
Space
Discovery cohort
Planets confirmed in 2016 at K2 (12 shown).
Host System: K2-73
Spectral Class
G-type yellow (Sun-like)
Effective Temperature
5,867 K — hotter than the Sun (5,778 K)
Estimated Age
—
Stellar Radius
1.058 R☉
Stellar Mass
1.020 M☉
Metallicity [Fe/H]
0.04
Extended Stellar Properties
Surface gravity (log g)
4.390 dex
Stellar density
1.266 g/cm³
Systemic radial velocity
-38.41 km/s
Rotational v·sin i
2.00 km/s
Activity index (log R'HK)
-4.999
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 17 bands
Astrometric Data
Parallax
3.686 mas
Total Proper Motion
50.201 mas/yr
PM Right Ascension
49.27 mas/yr
PM Declination
9.61 mas/yr
Galactic Cartesian (pc)
x = 0.895 · y = -0.417 · z = -0.157
Equatorial (J2000)
RA 335.02566° · Dec -9.05609°
Galactic ℓ, b
52.521° · -49.989°
Ecliptic λ, β
333.556° · 1.229°
HTM-20 index
374146318
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