Key parameters at a glance
- A radius of 3.29 Earth radii
- A mass of 10.80 Earth masses
- Surface gravity around 1.00 g
- An orbital period of 8.740 days
- Semi-major axis 0.0713 AU
- Equilibrium temperature 577 K (304 °C)
- Distance from Earth 2,287.19 light-years
- Earth Similarity Index 0.390
- Travel time at Voyager 1 speed 40,334,510 years
- Almost certainly tidally locked to its host star given the close orbit
Kepler-1999 b Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#287of 1978
top 14.5%
This planet
3.29R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | Kepler-1999 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 3.29 | 11.21 |
| Mass (M⊕) | 1.00 | 10.80 | 317.83 |
| Density (g/cm³) | 5.51 | 1.67 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.00 | 2.53 |
| Insolation (S⊕) | 1.00 | 26.17 | 0.037 |
Star Catalogue Identifiers
TIC
TIC 48131702
Gaia DR2
Gaia DR2 2119710538336363904
Gaia DR3
Gaia DR3 2119710538336363904
System
Kepler-1999
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 8.74 Earth days (2.4% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0713 AU.
Transit Fingerprint
Depth
0.143 %
Duration
3.866 h
Impact parameter b
0.957
Rp / R★
0.047917
Transit midpoint (BJD)
2,454,969.5829
Photometric dip
Transit produces a flux drop of 1,431 ppm lasting ≈ 3.87 h.
Extended Orbital Architecture
Planet / star radius ratio
0.047917
Semi-major axis / stellar radius
7.430
Impact parameter (b)
0.957
Transit mid-time (BJD)
2,454,969.5829
Angular separation (arcsec)
0.10200
Eq. Temperature
577K
(304 °C)
Insolation (S⊕)
26.17
Earth = 1.00
Earth Similarity (ESI)
0.390
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.
Discovery Paper
Primary reference
Valizadegan et al. 2023Instrument
Kepler CCD Array
Publication
2023-05
Observation locale
Space
Discovery cohort
Planets confirmed in 2023 at Kepler (12 shown).
Host System: Kepler-1999
Spectral Class
K-type orange
Effective Temperature
4,406 K — cooler than the Sun (5,778 K)
Estimated Age
—
Stellar Radius
0.628 R☉
Stellar Mass
0.632 M☉
Metallicity [Fe/H]
-0.24
Extended Stellar Properties
Surface gravity (log g)
4.643 dex
Stellar density
0.101 g/cm³
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 16 bands
Astrometric Data
Parallax
1.398 mas
Total Proper Motion
12.495 mas/yr
PM Right Ascension
10.09 mas/yr
PM Declination
-7.36 mas/yr
Galactic Cartesian (pc)
x = 0.143 · y = -0.650 · z = 0.746
Equatorial (J2000)
RA 282.37057° · Dec 48.25923°
Galactic ℓ, b
77.748° · 20.200°
Ecliptic λ, β
295.436° · 70.608°
HTM-20 index
2037188122
Similar Worlds
TOI-431 d
Sub-Neptune · K-type orange
Radius 3.29 R⊕ · 106.2 ly
K2-266 b
Sub-Neptune · K-type orange
Radius 3.30 R⊕ · 253.0 ly
Kepler-411 e
Sub-Neptune · K-type orange
Radius 3.28 R⊕ · 501.2 ly
Kepler-305 c
Sub-Neptune · K-type orange
Radius 3.30 R⊕ · 2,832.6 ly
HD 18143 b
Sub-Neptune · K-type orange
Radius 3.28 R⊕ · 73.5 ly
Kepler-1663 b
Sub-Neptune · K-type orange
Radius 3.30 R⊕ · 1,102.2 ly