Key parameters at a glance
- A radius of 2.55 Earth radii
- A mass of 7.04 Earth masses
- Surface gravity around 1.08 g
- An orbital period of 25.696 days
- Semi-major axis 0.1348 AU
- Equilibrium temperature 314 K (41 °C)
- Distance from Earth 1,709.86 light-years
- Earth Similarity Index 0.717
- Travel time at Voyager 1 speed 30,153,433 years
- Almost certainly tidally locked to its host star given the close orbit
Kepler-577 b Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#1105of 1978
top 55.8%
This planet
2.55R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | Kepler-577 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 2.55 | 11.21 |
| Mass (M⊕) | 1.00 | 7.04 | 317.83 |
| Density (g/cm³) | 5.51 | 2.33 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.08 | 2.53 |
| Insolation (S⊕) | 1.00 | 5.69 | 0.037 |
Star Catalogue Identifiers
TIC
TIC 378085037
Gaia DR2
Gaia DR2 2052212996988534656
Gaia DR3
Gaia DR3 2052212996988534656
System
Kepler-577
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 25.70 Earth days (7.0% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1348 AU.
Transit Fingerprint
Depth
0.113 %
Duration
3.929 h
Impact parameter b
0.513
Rp / R★
0.032058
Transit midpoint (BJD)
2,455,021.7896
Photometric dip
Transit produces a flux drop of 1,131 ppm lasting ≈ 3.93 h.
Extended Orbital Architecture
Planet / star radius ratio
0.032058
Semi-major axis / stellar radius
44.700
Impact parameter (b)
0.513
Transit mid-time (BJD)
2,455,021.7896
Angular separation (arcsec)
0.25700
Eq. Temperature
314K
(41 °C)
Insolation (S⊕)
5.69
Earth = 1.00
Earth Similarity (ESI)
0.717
0 = alien, 1 = Earth-identical
Inside the inner HZ boundary (too hot for liquid water) — liquid water is physically possible with adequate atmospheric pressure. 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-577
Spectral Class
K-type orange
Effective Temperature
4,984 K — cooler than the Sun (5,778 K)
Estimated Age
3.80 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
0.730 R☉
Stellar Mass
0.780 M☉
Metallicity [Fe/H]
-0.14
Extended Stellar Properties
Surface gravity (log g)
4.610 dex
Stellar density
2.566 g/cm³
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 16 bands
Astrometric Data
Parallax
1.879 mas
Total Proper Motion
10.018 mas/yr
PM Right Ascension
7.31 mas/yr
PM Declination
-6.85 mas/yr
Galactic Cartesian (pc)
x = 0.325 · y = -0.705 · z = 0.630
Equatorial (J2000)
RA 294.71199° · Dec 39.07373°
Galactic ℓ, b
72.761° · 8.366°
Ecliptic λ, β
309.311° · 59.186°
HTM-20 index
-1981079970
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K2-16 c
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