Plate No. 191 — in order of discoveryEntered 2013-10-28

TrES-2 b

A molten gas giant world orbiting TrES-2, a G0 V star, 702 ly from Earth.

Enter the system →Find it in the night sky →

The light now arriving from TrES-2 set out around 1324.
Astronomers have captured 8 spectra of its atmosphere — this world has been chemically probed.

1 world1s = 1s

Orbit shapes and relative timing are true — worlds sweep faster near their star, as Kepler demands. Spacing is drawn to true scale when the system allows; wide systems open compressed so inner and outer worlds share the page. Dashed orbits are derived from period alone.

The measures

Earth

1.0 R⊕

TrES-2 b

15.24 R⊕

Jupiter

11.2 R⊕

frozenEarth 255 K · b 1,466 Kstar-hot

Life outlook

Hostile

2/ 100

Warmth: 0 · weight 40%
Size: 0 · weight 30%
Star: 99 · weight 20%
Orbit: 100 · weight 10%

A strict Earth-similarity index, not a detection: every factor peaks at Earth's own value and they multiply, so one hostile factor sinks the score — only a true Earth twin would reach 100. Equilibrium temperature ignores atmospheres, which can warm a cold world into comfort, or turn a Venus into a furnace.

The world

Class: Gas Giant
Radius: 15.244 R⊕
Mass: 473.567 M⊕
Density: 0.88 g/cm³
Equilibrium temperature: 1,466 K
Starlight received: 903.86× Earth

The orbit

Period: 2.471 days
Semi-major axis: 0.0357 AU
Eccentricity: 0

The star

Host: TrES-2
Spectral type: G0 V
Temperature: 5,850 K
Radius: 1.12 R☉
Mass: 1.36 M☉

The system

Distance: 702 ly · 215.3 pc
Known planets: 1
Stars: 2
Coordinates: RA 286.81° · Dec 49.32°

The observation

Star brightness: V 11.3 · telescope
Atmospheric spectra: 3 transmission · 5 emission
Stellar age: 3.6 Gyr

The record

Method: Transit
Facility: TrES
Discovery: 2006
Parameters published: —

Discovery paperO'Donovan et al. 2006