Key parameters at a glance
- A radius of 17.09 Earth radii
- A mass of 416.36 Earth masses
- Surface gravity around 1.42 g
- An orbital period of 3.080 days
- Semi-major axis 0.0488 AU
- Equilibrium temperature 2,087 K (1814 °C)
- Distance from Earth 738.74 light-years
- Earth Similarity Index 0.051
- Travel time at Voyager 1 speed 13,027,738 years
KELT-17 b Planet Profile
Physical Specs
Classification
Planet Type
Gas Giant
Discovery
Size rank in cohort
Rank by radius
#107of 1771
top 6.0%
This planet
17.09R⊕
Gas Giant median
13.52R⊕
Nearest-size peers
| Metric | Earth | KELT-17 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 17.09 | 11.21 |
| Mass (M⊕) | 1.00 | 416.36 | 317.83 |
| Density (g/cm³) | 5.51 | 0.46 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.42 | 2.53 |
| Insolation (S⊕) | 1.00 | 3,331.87 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 416.357 M⊕ | Direct mass measurement (not derived). |
| Minimum mass (M sin i) | 416.357 M⊕ | Lower bound from radial-velocity fitting. |
| Computed mass | 418.032 M⊕ | Model-computed mass (e.g. from mass-radius relation). |
Star Catalogue Identifiers
TIC
TIC 6893917
Gaia DR2
Gaia DR2 651935220461650560
Gaia DR3
Gaia DR3 651935220461650560
System
KELT-17
Percentile among Gas Giant cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 3.08 Earth days (0.8% of a terrestrial year) at a mean orbital distance of 0.0488 AU.
Transit Fingerprint
Depth
0.907 %
Duration
3.475 h
Impact parameter b
0.570
Rp / R★
0.095260
Transit midpoint (BJD)
2,457,226.1422
Photometric dip
Transit produces a flux drop of 9,070 ppm lasting ≈ 3.48 h.
Extended Orbital Architecture
Planet / star radius ratio
0.095260
Semi-major axis / stellar radius
6.380
Impact parameter (b)
0.570
RV semi-amplitude (K)
131.000 m/s
Transit mid-time (BJD)
2,457,226.1422
Sky-projected obliquity (λ)
-115.90°
True obliquity (ψ)
116.00°
Angular separation (arcsec)
0.21500
Eq. Temperature
2,087K
(1814 °C)
Insolation (S⊕)
3,331.87
Earth = 1.00
Earth Similarity (ESI)
0.051
0 = alien, 1 = Earth-identical
Inside the inner HZ boundary (too hot for liquid water) — the dayside is scorched.
Detection Signatures
Transit photometry
A transit dip has been observed from at least one telescope.
Radial velocity
Stellar wobble has been measured spectroscopically.
Discovery Paper
Primary reference
Zhou et al. 2016Instrument
Multiple Instruments
Publication
2016-11
Observation locale
Ground
Host System: KELT-17
Spectral Class
A-type white
Effective Temperature
7,454 K — hotter than the Sun (5,778 K)
Estimated Age
0.65 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
1.645 R☉
Stellar Mass
1.635 M☉
Metallicity [Fe/H]
-0.02
Extended Stellar Properties
Surface gravity (log g)
4.220 dex
Stellar density
0.518 g/cm³
Systemic radial velocity
28.00 km/s
Rotational v·sin i
44.20 km/s
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 13 bands
Astrometric Data
Parallax
4.387 mas
Total Proper Motion
25.507 mas/yr
PM Right Ascension
-25.43 mas/yr
PM Declination
-2.01 mas/yr
Galactic Cartesian (pc)
x = -0.566 · y = 0.790 · z = 0.237
Equatorial (J2000)
RA 125.61741° · Dec 13.73531°
Galactic ℓ, b
210.377° · 26.277°
Ecliptic λ, β
124.632° · -5.524°
HTM-20 index
188796932
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