Key parameters at a glance
- A radius of 3.05 Earth radii
- A mass of 9.53 Earth masses
- Surface gravity around 1.02 g
- An orbital period of 11.720 days
- Semi-major axis 0.0729 AU
- Equilibrium temperature 849 K (576 °C)
- Distance from Earth 1,004.90 light-years
- Earth Similarity Index 0.275
- Travel time at Voyager 1 speed 17,721,462 years
- Almost certainly tidally locked to its host star given the close orbit
K2-273 b Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#472of 1978
top 23.8%
This planet
3.05R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | K2-273 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 3.05 | 11.21 |
| Mass (M⊕) | 1.00 | 9.53 | 317.83 |
| Density (g/cm³) | 5.51 | 1.85 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.02 | 2.53 |
| Insolation (S⊕) | 1.00 | — | 0.037 |
Star Catalogue Identifiers
TIC
TIC 175233369
Gaia DR2
Gaia DR2 659701895721176192
Gaia DR3
Gaia DR3 659701895721176192
System
K2-273
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 11.72 Earth days (3.2% of a terrestrial year) at a mean orbital distance of 0.0729 AU.
Transit Fingerprint
Depth
0.143 %
Duration
4.872 h
Impact parameter b
0.370
Rp / R★
0.032700
Transit midpoint (BJD)
2,457,149.0962
Photometric dip
Transit produces a flux drop of 1,434 ppm lasting ≈ 4.87 h.
Extended Orbital Architecture
Planet / star radius ratio
0.032700
Semi-major axis / stellar radius
18.490
Impact parameter (b)
0.370
Transit mid-time (BJD)
2,457,149.0962
Angular separation (arcsec)
0.23700
Eq. Temperature
849K
(576 °C)
Insolation (S⊕)
—
Earth = 1.00
Earth Similarity (ESI)
0.275
0 = alien, 1 = Earth-identical
Insufficient insolation data — the surface is too hot to retain surface water. Close-orbiting tidally-locked around a cool host.
Discovery Paper
Primary reference
Livingston et al. 2018Instrument
Kepler CCD Array
Publication
2018-12
Observation locale
Space
Discovery cohort
Planets confirmed in 2018 at K2 (12 shown).
Host System: K2-273
Spectral Class
K-type orange
Effective Temperature
5,161 K — cooler than the Sun (5,778 K)
Estimated Age
—
Stellar Radius
0.850 R☉
Stellar Mass
0.890 M☉
Metallicity [Fe/H]
0.20
Extended Stellar Properties
Surface gravity (log g)
4.530 dex
Stellar density
0.037 g/cm³
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 17 bands
Astrometric Data
Parallax
3.217 mas
Total Proper Motion
32.861 mas/yr
PM Right Ascension
-32.42 mas/yr
PM Declination
-5.37 mas/yr
Galactic Cartesian (pc)
x = -0.605 · y = 0.727 · z = 0.326
Equatorial (J2000)
RA 129.77689° · Dec 19.01000°
Galactic ℓ, b
206.521° · 31.969°
Ecliptic λ, β
127.220° · 0.563°
HTM-20 index
51798791
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