Key parameters at a glance
- A radius of 5.07 Earth radii
- A mass of 34.01 Earth masses
- Surface gravity around 1.32 g
- An orbital period of 10.137 days
- Semi-major axis 0.0986 AU
- Equilibrium temperature 1,185 K (912 °C)
- Distance from Earth 1,691.53 light-years
- Earth Similarity Index 0.163
- Travel time at Voyager 1 speed 29,830,069 years
K2-98 b Planet Profile
Physical Specs
Classification
Planet Type
Neptune-like
Discovery
Size rank in cohort
Rank by radius
#375of 574
top 65.2%
This planet
5.07R⊕
Neptune-like median
6.39R⊕
Nearest-size peers
| Metric | Earth | K2-98 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 5.07 | 11.21 |
| Mass (M⊕) | 1.00 | 34.01 | 317.83 |
| Density (g/cm³) | 5.51 | 1.40 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.32 | 2.53 |
| Insolation (S⊕) | 1.00 | 339.00 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 34.008 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
TIC
TIC 366410512
Gaia DR2
Gaia DR2 601199802584914816
Gaia DR3
Gaia DR3 601199802584914816
System
K2-98
Percentile among Neptune-like cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 10.14 Earth days (2.8% of a terrestrial year) on a mildly elliptical path at a mean orbital distance of 0.0986 AU.
Transit Fingerprint
Depth
0.093 %
Duration
5.122 h
Impact parameter b
0.370
Rp / R★
0.030490
Transit midpoint (BJD)
2,457,662.9532
Photometric dip
Transit produces a flux drop of 930 ppm lasting ≈ 5.12 h.
Extended Orbital Architecture
Planet / star radius ratio
0.030490
Semi-major axis / stellar radius
13.940
Impact parameter (b)
0.370
RV semi-amplitude (K)
8.800 m/s
Transit mid-time (BJD)
2,457,662.9532
Long. of periastron (ω)
14.00°
Angular separation (arcsec)
0.19000
Eq. Temperature
1,185K
(912 °C)
Insolation (S⊕)
339.00
Earth = 1.00
Earth Similarity (ESI)
0.163
0 = alien, 1 = Earth-identical
Inside the inner HZ boundary (too hot for liquid water) — the dayside is scorched.
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
Barrag Aacute N et al. 2016Instrument
Kepler CCD Array
Publication
2016-12
Observation locale
Space
Discovery cohort
Planets confirmed in 2016 at K2 (12 shown).
Host System: K2-98
Spectral Class
F-type yellow-white
Effective Temperature
6,260 K — hotter than the Sun (5,778 K)
Estimated Age
3.40 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
1.518 R☉
Stellar Mass
1.246 M☉
Metallicity [Fe/H]
-0.04
Extended Stellar Properties
Surface gravity (log g)
4.169 dex
Stellar density
0.499 g/cm³
Systemic radial velocity
76.75 km/s
Rotational v·sin i
6.10 km/s
Activity index (log R'HK)
-5.189
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 17 bands
Astrometric Data
Parallax
1.900 mas
Total Proper Motion
18.593 mas/yr
PM Right Ascension
-15.97 mas/yr
PM Declination
-9.52 mas/yr
Galactic Cartesian (pc)
x = -0.583 · y = 0.788 · z = 0.200
Equatorial (J2000)
RA 126.48821° · Dec 11.51109°
Galactic ℓ, b
213.027° · 26.138°
Ecliptic λ, β
125.990° · -7.486°
HTM-20 index
46073757
Similar Worlds
HIP 41378 e
Neptune-like · F-type yellow-white
Radius 4.92 R⊕ · 346.7 ly
Kepler-25 c
Neptune-like · F-type yellow-white
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Kepler-31 c
Neptune-like · F-type yellow-white
Radius 5.30 R⊕ · 5,429.3 ly
Kepler-669 b
Neptune-like · F-type yellow-white
Radius 4.83 R⊕ · 6,729.9 ly
Kepler-1640 b
Neptune-like · F-type yellow-white
Radius 4.82 R⊕ · 6,065.8 ly
Kepler-1527 b
Neptune-like · F-type yellow-white
Radius 4.77 R⊕ · 6,008.2 ly