|"Exoplanet Comparison TrES-1 b" by Aldaron, a.k.a. Aldaron - Own work,|
Licensed under CC BY-SA 3.0 via Commons
Guide Star Catalog
The Guide Star Catalog (GSC) is also known as the Hubble Space Telescope, Guide Catalog (HSTGC). It is a star catalog compiled to support the Hubble Space Telescope with targeting off-axis stars.
GSC-I contained approximately 20,000,000 stars with apparent magnitudes of 6 to 15. GSC-II contains 945,592,683 stars out to magnitude 21. As far as possible, binary stars and non-stellar objects have been excluded or flagged as not meeting the requirements of Fine Guidance Sensors. This is the first full sky star catalog created specifically for navigation in outer space.
TrES-1b - a hot Jupiter
In 2004 the extrasolar planet TrES-1b was found to be orbiting this star by the Trans-Atlantic Exoplanet Survey using the transit method. The planet was detected crossing its parent star using a small 4-inch-diameter (100 mm) telescope. The discovery was confirmed by the Keck Observatory using the radial velocity method, allowing its mass to be determined.
The Trans-atlantic Exoplanet Survey or TrES, uses three 4-inch (10 cm) telescopes located at Lowell Observatory, Palomar Observatory, and the Canary Islands to locate exoplanets.
TrES-1b mass and radius indicate that it is a Jovian planet with a similar bulk composition to Jupiter. Unlike Jupiter, but similar to many other planets detected around other stars, TrES-1 is located very close to its star, and belongs to the class of planets known as hot Jupiters.
On March 22, 2005, Astronomers using NASA's Spitzer Space Telescope took advantage of the discovery to directly capture the infrared light of two previously detected planets orbiting outside our solar system. Their findings revealed the temperatures and orbits of the planets.
Upcoming Spitzer observations using a variety of infrared wavelengths may provide more information about the planets' winds and atmospheric compositions. It enabled determination of TrES-1's temperature, which is in excess of 1000 K (1340 °F). The planet's Bond albedo was found to be 0.31 ± 0.14.
Albedo or reflection coefficient, is derived from Latin albedo "whiteness" (or reflected sunlight) in turn from albus "white", is the diffuse reflectivity or reflecting power of a surface. It is the ratio of reflected radiation from the surface to incident radiation upon it.
Its dimensionless nature lets it be expressed as a percentage and is measured on a scale from zero for no reflection of a perfectly black surface to 1 for perfect reflection of a white surface.
Albedo depends on the frequency of the radiation. When quoted unqualified, it usually refers to some appropriate average across the spectrum of visible light.
Click on the links provided under the snippets to get more details about the subjects and references.