Key parameters at a glance
- A radius of 8.73 Earth radii
- A mass of 14.70 Earth masses
- Surface gravity around 0.19 g
- An orbital period of 49.409 days
- Semi-major axis 0.2566 AU
- Equilibrium temperature 497 K (224 °C)
- Distance from Earth 4,681.77 light-years
- Earth Similarity Index 0.218
- Travel time at Voyager 1 speed 82,563,074 years
1 sibling around Kepler-177
Kepler-177 c shares its host star with 1 other confirmed planet. Side-by-side measurements below.
| Planet | Type | Radius (R⊕) | Mass (M⊕) | Period (d) | Eq. T (K) | Year |
|---|---|---|---|---|---|---|
| Kepler-177 b | Sub-Neptune | 3.50 | 5.84 | 36.860 | 549 | 2013 |
| Kepler-177 c this | Neptune-like | 8.73 | 14.70 | 49.409 | 497 | 2013 |
Kepler-177 c Planet Profile
Physical Specs
Classification
Planet Type
Neptune-like
Discovery
Size rank in cohort
Rank by radius
#102of 574
top 17.6%
This planet
8.73R⊕
Neptune-like median
6.39R⊕
Nearest-size peers
| Metric | Earth | Kepler-177 c | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 8.73 | 11.21 |
| Mass (M⊕) | 1.00 | 14.70 | 317.83 |
| Density (g/cm³) | 5.51 | 0.12 | 1.33 |
| Surface Gravity (g) | 1.00 | 0.19 | 2.53 |
| Insolation (S⊕) | 1.00 | 25.40 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 14.700 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
TIC
TIC 158172348
Gaia DR2
Gaia DR2 2106339927188171776
Gaia DR3
Gaia DR3 2106339927188171776
System
Kepler-177
Percentile among Neptune-like cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 49.41 Earth days (13.5% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.2566 AU.
Transit Fingerprint
Depth
0.364 %
Duration
5.243 h
Impact parameter b
0.885
Rp / R★
0.060360
Transit midpoint (BJD)
2,455,031.2389
Photometric dip
Transit produces a flux drop of 3,643 ppm lasting ≈ 5.24 h.
Extended Orbital Architecture
Planet / star radius ratio
0.060360
Semi-major axis / stellar radius
42.080
Impact parameter (b)
0.885
Transit mid-time (BJD)
2,455,031.2389
Angular separation (arcsec)
0.17900
Eq. Temperature
497K
(224 °C)
Insolation (S⊕)
25.40
Earth = 1.00
Earth Similarity (ESI)
0.218
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.
Transit timing variations
Gravitational interactions from neighbours have been detected.
Discovery Paper
Discovery cohort
Planets confirmed in 2013 at Kepler (12 shown).
Host System: Kepler-177
Spectral Class
G-type yellow (Sun-like)
Effective Temperature
5,732 K — cooler than the Sun (5,778 K)
Estimated Age
11.75 Gyr — older than the Sun (4.6 Gyr)
Stellar Radius
1.324 R☉
Stellar Mass
0.921 M☉
Metallicity [Fe/H]
-0.11
Extended Stellar Properties
Surface gravity (log g)
4.100 dex
Stellar density
0.400 g/cm³
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 16 bands
Astrometric Data
Parallax
0.668 mas
Total Proper Motion
4.183 mas/yr
PM Right Ascension
4.05 mas/yr
PM Declination
-1.04 mas/yr
Galactic Cartesian (pc)
x = 0.195 · y = -0.679 · z = 0.708
Equatorial (J2000)
RA 286.04714° · Dec 45.05320°
Galactic ℓ, b
75.497° · 16.724°
Ecliptic λ, β
299.768° · 66.841°
HTM-20 index
-1955552715
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