Key parameters at a glance
- A radius of 2.26 Earth radii
- A mass of 5.73 Earth masses
- Surface gravity around 1.12 g
- An orbital period of 48.431 days
- Semi-major axis 0.2390 AU
- Equilibrium temperature 396 K (123 °C)
- Distance from Earth 2,427.56 light-years
- Earth Similarity Index 0.628
- Travel time at Voyager 1 speed 42,810,010 years
- Almost certainly tidally locked to its host star given the close orbit
Kepler-1261 b Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#1572of 1978
top 79.4%
This planet
2.26R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | Kepler-1261 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 2.26 | 11.21 |
| Mass (M⊕) | 1.00 | 5.73 | 317.83 |
| Density (g/cm³) | 5.51 | 2.73 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.12 | 2.53 |
| Insolation (S⊕) | 1.00 | 4.74 | 0.037 |
Star Catalogue Identifiers
TIC
TIC 48506742
Gaia DR2
Gaia DR2 2131968890395913344
Gaia DR3
Gaia DR3 2131968890395913344
System
Kepler-1261
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 48.43 Earth days (13.3% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.2390 AU.
Transit Fingerprint
Depth
0.089 %
Duration
3.755 h
Impact parameter b
0.308
Rp / R★
0.027217
Transit midpoint (BJD)
2,454,974.4603
Photometric dip
Transit produces a flux drop of 886 ppm lasting ≈ 3.76 h.
Extended Orbital Architecture
Planet / star radius ratio
0.027217
Semi-major axis / stellar radius
54.200
Impact parameter (b)
0.308
Transit mid-time (BJD)
2,454,974.4603
Angular separation (arcsec)
0.32100
Eq. Temperature
396K
(123 °C)
Insolation (S⊕)
4.74
Earth = 1.00
Earth Similarity (ESI)
0.628
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
Morton et al. 2016Instrument
Kepler CCD Array
Publication
2016-05
Observation locale
Space
Discovery cohort
Planets confirmed in 2016 at Kepler (12 shown).
Host System: Kepler-1261
Spectral Class
K-type orange
Effective Temperature
5,006 K — cooler than the Sun (5,778 K)
Estimated Age
4.47 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
0.770 R☉
Stellar Mass
0.820 M☉
Metallicity [Fe/H]
0.03
Extended Stellar Properties
Surface gravity (log g)
4.580 dex
Stellar density
7.265 g/cm³
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 16 bands
Astrometric Data
Parallax
1.315 mas
Total Proper Motion
5.569 mas/yr
PM Right Ascension
0.21 mas/yr
PM Declination
-5.56 mas/yr
Galactic Cartesian (pc)
x = 0.173 · y = -0.635 · z = 0.752
Equatorial (J2000)
RA 285.23248° · Dec 48.80670°
Galactic ℓ, b
78.962° · 18.594°
Ecliptic λ, β
301.376° · 70.591°
HTM-20 index
-167007589
Similar Worlds
Kepler-1996 b
Sub-Neptune · K-type orange
Radius 2.26 R⊕ · 1,436.9 ly
K2-346 b
Sub-Neptune · K-type orange
Radius 2.26 R⊕ · 344.4 ly
Kepler-568 b
Sub-Neptune · K-type orange
Radius 2.26 R⊕ · 426.1 ly
Kepler-1242 b
Sub-Neptune · K-type orange
Radius 2.26 R⊕ · 2,242.7 ly
Kepler-1388 c
Sub-Neptune · K-type orange
Radius 2.26 R⊕ · 1,480.1 ly
K2-5 c
Sub-Neptune · K-type orange
Radius 2.26 R⊕ · 661.9 ly