Key parameters at a glance
- A radius of 3.50 Earth radii
- A mass of 5.84 Earth masses
- Surface gravity around 0.48 g
- An orbital period of 36.860 days
- Semi-major axis 0.2110 AU
- Equilibrium temperature 549 K (276 °C)
- Distance from Earth 4,681.77 light-years
- Earth Similarity Index 0.352
- Travel time at Voyager 1 speed 82,563,074 years
1 sibling around Kepler-177
Kepler-177 b 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 this | Sub-Neptune | 3.50 | 5.84 | 36.860 | 549 | 2013 |
| Kepler-177 c | Neptune-like | 8.73 | 14.70 | 49.409 | 497 | 2013 |
Kepler-177 b Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#182of 1978
top 9.2%
This planet
3.50R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | Kepler-177 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 3.50 | 11.21 |
| Mass (M⊕) | 1.00 | 5.84 | 317.83 |
| Density (g/cm³) | 5.51 | 0.75 | 1.33 |
| Surface Gravity (g) | 1.00 | 0.48 | 2.53 |
| Insolation (S⊕) | 1.00 | 30.40 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 5.840 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 Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 36.86 Earth days (10.1% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.2110 AU.
Transit Fingerprint
Depth
0.071 %
Duration
7.495 h
Impact parameter b
0.474
Rp / R★
0.024990
Transit midpoint (BJD)
2,454,971.9068
Photometric dip
Transit produces a flux drop of 714 ppm lasting ≈ 7.50 h.
Extended Orbital Architecture
Planet / star radius ratio
0.024990
Semi-major axis / stellar radius
38.430
Impact parameter (b)
0.474
Transit mid-time (BJD)
2,454,971.9068
Angular separation (arcsec)
0.14700
Eq. Temperature
549K
(276 °C)
Insolation (S⊕)
30.40
Earth = 1.00
Earth Similarity (ESI)
0.352
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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TOI-2196 b
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