Key parameters at a glance
- A radius of 12.67 Earth radii
- A mass of 266.98 Earth masses
- Surface gravity around 1.66 g
- An orbital period of 3.030 days
- Semi-major axis 0.0393 AU
- Equilibrium temperature 1,140 K (867 °C)
- Distance from Earth 520.73 light-years
- Earth Similarity Index 0.121
- Travel time at Voyager 1 speed 9,183,146 years
- Almost certainly tidally locked to its host star given the close orbit
TrES-1 b Planet Profile
Physical Specs
Classification
Planet Type
Gas Giant
Discovery
Size rank in cohort
Rank by radius
#1170of 1771
top 66.0%
This planet
12.67R⊕
Gas Giant median
13.52R⊕
Nearest-size peers
| Metric | Earth | TrES-1 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 12.67 | 11.21 |
| Mass (M⊕) | 1.00 | 266.98 | 317.83 |
| Density (g/cm³) | 5.51 | 0.71 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.66 | 2.53 |
| Insolation (S⊕) | 1.00 | 318.46 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 266.977 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
TIC
TIC 120757718
Gaia DR2
Gaia DR2 2098964849867337856
Gaia DR3
Gaia DR3 2098964849867337856
System
TrES-1
Percentile among Gas Giant cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 3.03 Earth days (0.8% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0393 AU.
Transit Fingerprint
Depth
1.800 %
Duration
2.508 h
Impact parameter b
0.191
Rp / R★
0.135800
Transit midpoint (BJD)
2,453,186.8063
Photometric dip
Transit produces a flux drop of 18,000 ppm lasting ≈ 2.51 h.
Extended Orbital Architecture
Planet / star radius ratio
0.135800
Semi-major axis / stellar radius
10.480
Impact parameter (b)
0.191
RV semi-amplitude (K)
115.200 m/s
Transit mid-time (BJD)
2,453,186.8063
Sky-projected obliquity (λ)
30.00°
Angular separation (arcsec)
0.24600
Eq. Temperature
1,140K
(867 °C)
Insolation (S⊕)
318.46
Earth = 1.00
Earth Similarity (ESI)
0.121
0 = alien, 1 = Earth-identical
Inside the inner HZ boundary (too hot for liquid water) — the dayside is scorched. Close-orbiting tidally-locked around a cool host.
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
Alonso et al. 2004Instrument
2K CCD Sensor
Publication
2004-10
Observation locale
Ground
Host System: TrES-1
Spectral Class
K-type orange
Effective Temperature
5,230 K — cooler than the Sun (5,778 K)
Estimated Age
3.70 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
0.850 R☉
Stellar Mass
1.040 M☉
Metallicity [Fe/H]
0.02
Extended Stellar Properties
Surface gravity (log g)
4.570 dex
Stellar density
2.370 g/cm³
Systemic radial velocity
-20.52 km/s
Rotational v·sin i
1.30 km/s
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 11 bands
Astrometric Data
Parallax
6.235 mas
Total Proper Motion
38.125 mas/yr
PM Right Ascension
-32.21 mas/yr
PM Declination
-20.40 mas/yr
Galactic Cartesian (pc)
x = 0.222 · y = -0.771 · z = 0.597
Equatorial (J2000)
RA 286.04088° · Dec 36.63254°
Galactic ℓ, b
67.464° · 13.441°
Ecliptic λ, β
295.242° · 58.674°
HTM-20 index
181547610
Observation Record
Photometric series
35
RV measurements
2
Emission spectra
4
Archive notes
1
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