Key parameters at a glance
- A radius of 3.88 Earth radii
- A mass of 11.12 Earth masses
- Surface gravity around 0.74 g
- An orbital period of 11.898 days
- Semi-major axis 0.0982 AU
- Equilibrium temperature 749 K (476 °C)
- Distance from Earth 945.29 light-years
- Earth Similarity Index 0.271
- Travel time at Voyager 1 speed 16,670,156 years
2 siblings around K2-19
K2-19 c shares its host star with 2 other confirmed planets. Side-by-side measurements below.
K2-19 c Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#34of 1978
top 1.7%
This planet
3.88R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | K2-19 c | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 3.88 | 11.21 |
| Mass (M⊕) | 1.00 | 11.12 | 317.83 |
| Density (g/cm³) | 5.51 | 1.05 | 1.33 |
| Surface Gravity (g) | 1.00 | 0.74 | 2.53 |
| Insolation (S⊕) | 1.00 | 51.00 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 11.120 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
TIC
TIC 281885301
Gaia DR2
Gaia DR2 3798833775141351552
Gaia DR3
Gaia DR3 3798833775141351552
System
K2-19
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 11.90 Earth days (3.3% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0982 AU.
Transit Fingerprint
Depth
0.233 %
Duration
3.823 h
Impact parameter b
0.299
Rp / R★
0.043210
Transit midpoint (BJD)
2,456,829.1849
Photometric dip
Transit produces a flux drop of 2,325 ppm lasting ≈ 3.82 h.
Extended Orbital Architecture
Planet / star radius ratio
0.043210
Semi-major axis / stellar radius
25.610
Impact parameter (b)
0.299
RV semi-amplitude (K)
3.368 m/s
Transit mid-time (BJD)
2,456,829.1849
Long. of periastron (ω)
252.00°
Angular separation (arcsec)
0.33900
Eq. Temperature
749K
(476 °C)
Insolation (S⊕)
51.00
Earth = 1.00
Earth Similarity (ESI)
0.271
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.
Transit timing variations
Gravitational interactions from neighbours have been detected.
Discovery Paper
Primary reference
Dai et al. 2016Instrument
Kepler CCD Array
Publication
2016-06
Observation locale
Space
Discovery cohort
Planets confirmed in 2015 at K2 (12 shown).
Host System: K2-19
Spectral Class
G-type yellow (Sun-like)
Effective Temperature
5,350 K — cooler than the Sun (5,778 K)
Estimated Age
1.70 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
0.824 R☉
Stellar Mass
0.892 M☉
Metallicity [Fe/H]
0.03
Extended Stellar Properties
Surface gravity (log g)
4.556 dex
Stellar density
1.590 g/cm³
Systemic radial velocity
7.31 km/s
Rotational v·sin i
3.00 km/s
Rotation period
18.36 days
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 17 bands
Astrometric Data
Parallax
3.423 mas
Total Proper Motion
19.300 mas/yr
PM Right Ascension
-18.79 mas/yr
PM Declination
4.42 mas/yr
Galactic Cartesian (pc)
x = -0.996 · y = 0.088 · z = 0.011
Equatorial (J2000)
RA 174.96025° · Dec 0.60360°
Galactic ℓ, b
267.029° · 58.394°
Ecliptic λ, β
175.131° · -1.448°
HTM-20 index
1093139326
Similar Worlds
Kepler-368 c
Sub-Neptune · G-type yellow (Sun-like)
Radius 3.88 R⊕ · 2,514.6 ly
K2-100 b
Sub-Neptune · G-type yellow (Sun-like)
Radius 3.88 R⊕ · 616.3 ly
HD 20003 c
Sub-Neptune · G-type yellow (Sun-like)
Radius 3.89 R⊕ · 136.4 ly
Kepler-266 c
Sub-Neptune · G-type yellow (Sun-like)
Radius 3.89 R⊕ · 4,470.9 ly
HD 51608 c
Sub-Neptune · G-type yellow (Sun-like)
Radius 3.87 R⊕ · 114.3 ly
HD 42618 b
Sub-Neptune · G-type yellow (Sun-like)
Radius 3.89 R⊕ · 79.4 ly