TrES-1b is an

extrasolar planet An exoplanet or extrasolar planet is a planet outside the Solar System. The first possible evidence of an exoplanet was noted in 1917 but was not recognized as such. The first confirmation of detection occurred in 1992. A different planet, init ...

approximately 523 light-years away in the constellation of

Lyra Lyra (; Latin for lyre, from Greek ''λύρα'') is a small constellation. It is one of the 48 listed by the 2nd century astronomer Ptolemy, and is one of the modern 88 constellations recognized by the International Astronomical Union. Lyra wa ...

(the Lyre). The planet's

mass Mass is an intrinsic property of a body. It was traditionally believed to be related to the quantity of matter in a physical body, until the discovery of the atom and particle physics. It was found that different atoms and different eleme ...

and

radius In classical geometry, a radius ( : radii) of a circle or sphere is any of the line segments from its center to its perimeter, and in more modern usage, it is also their length. The name comes from the latin ''radius'', meaning ray but also the ...

indicate that it is a

Jovian planet The giant planets constitute a diverse type of planet much larger than Earth. They are usually primarily composed of low-boiling-point materials ( volatiles), rather than rock or other solid matter, but massive solid planets can also exist. T ...

with a similar bulk composition to

Jupiter Jupiter is the fifth planet from the Sun and the largest in the Solar System. It is a gas giant with a mass more than two and a half times that of all the other planets in the Solar System combined, but slightly less than one-thousandth t ...

. 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 Jupiter Hot Jupiters (sometimes called hot Saturns) are a class of gas giant exoplanets that are inferred to be physically similar to Jupiter but that have very short orbital periods (). The close proximity to their stars and high surface-atmosphere tem ...

s. The planet was discovered orbiting around

GSC 02652-01324 GSC 02652-01324 is an orange dwarf main sequence star approximately 523 light-years away in the constellation of Lyra (the Lyre). Planetary system In 2004 the extrasolar planet TrES-1b was found to be orbiting this star by the Trans-At ...

(an

orange dwarf A K-type main-sequence star, also referred to as a K-type dwarf or an orange dwarf, is a main-sequence (hydrogen-burning) star of spectral type K and luminosity class V. These stars are intermediate in size between red M-type main-sequence stars ...

star).

Detection and discovery

TrES-1b was discovered by the

Trans-Atlantic Exoplanet Survey The Trans-Atlantic Exoplanet Survey, or ''TrES'', used three 4-inch (10 cm) telescopes located at Lowell Observatory, Palomar Observatory, and Teide Observatory to locate exoplanets. It was made using the network of small, relatively inexpe ...

by detecting the

transit Transit may refer to: Arts and entertainment Film * ''Transit'' (1979 film), a 1979 Israeli film * ''Transit'' (2005 film), a film produced by MTV and Staying-Alive about four people in countries in the world * ''Transit'' (2006 film), a 2006 ...

of the planet across its parent star using a telescope. The discovery was confirmed by the

Keck Observatory The W. M. Keck Observatory is an astronomical observatory with two telescopes at an elevation of 4,145 meters (13,600 ft) near the summit of Mauna Kea in the U.S. state of Hawaii. Both telescopes have aperture primary mirrors, and when co ...

using the

radial velocity method Doppler spectroscopy (also known as the radial-velocity method, or colloquially, the wobble method) is an indirect method for finding extrasolar planets and brown dwarfs from radial-velocity measurements via observation of Doppler shifts in t ...

, which allowed its mass to be determined.

Transit

On March 22, 2005, Astronomers using

NASA The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the US federal government responsible for the civil List of government space agencies, space program ...

's Spitzer Space Telescope took advantage of this fact 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 Temperature is a physical quantity that expresses quantitatively the perceptions of hotness and coldness. Temperature is measurement, measured with a thermometer. Thermometers are calibrated in various Conversion of units of temperature, temp ...

, which is in excess of 1000 K (1340 °F). The planet's

Bond albedo The Bond albedo (or ''spheric albedo'' or ''planetary albedo'' or ''bolometric albedo''), named after the American astronomer George Phillips Bond (1825–1865), who originally proposed it, is the fraction of power in the total electromagnetic ra ...

was found to be 0.31 ± 0.14. In the

infrared Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from around ...

panel, the colors reflect what our eyes might see if we could retune them to the invisible, infrared portion of the light spectrum. The hot star is less bright in infrared light than in visible and appears fainter. The warm planet peaks in infrared light, so is shown brighter. Their hues represent relative differences in temperature. Because the star is hotter than the planet, and because hotter objects give off more blue light than red, the star is depicted in blue, and the planet, red. The overall look of the planet is inspired by theoretical models of hot, gas giant planets. These "hot Jupiters" are similar to Jupiter in composition and mass, but are expected to look quite different at such high temperatures.

Radial velocity

The transit light-curve signature in the course of the TrES multi-site transiting planet survey, and confirmed the planetary nature of the companion via multicolor photometry and precise radial velocity measurements. With this, the planet has an orbital period similar to that of

HD 209458 b HD 209458 b, which is also nicknamed Osiris after the Egyptian god, is an exoplanet that orbits the solar analog HD 209458 in the constellation Pegasus, some from the Solar System. The radius of the planet's orbit is , or one-eighth the radius ...

, but about twice as long as those of the

Optical Gravitational Lensing Experiment The Optical Gravitational Lensing Experiment (OGLE) is a Polish astronomical project based at the University of Warsaw that runs a long-term variability sky survey (1992–present). The main goals are the detection and classification of variable ...

(OGLE) transiting planets. Its mass is similar to that of HD 209458 b, but its radius is significantly smaller and fits the theoretical models without the need for an additional source of heat deep in the atmosphere, as has been invoked by some investigators for HD 209458 b.

Rotation

The spin-orbit angle using the

Rossiter–McLaughlin effect The Rossiter–McLaughlin effect is a spectroscopic phenomenon observed when an object moves across the face of a star. Description The Rossiter–McLaughlin effect is a spectroscopic phenomenon observed when either an eclipsing binary's secon ...

was measured to be +30° in 2007, and measurement was not updated by 2012

Physical characteristics

Hubble might find water in TrES-1, and it would give a much more precise measurement of the planet's size, and even allow us to search for moons. A satellite is unlikely however, given the likely history and current orbital configuration for the planet, the research team concluded. There are only 11

exomoon An exomoon or extrasolar moon is a natural satellite that orbits an exoplanet or other non-stellar extrasolar body. Exomoons are difficult to detect and confirm using current techniques, and to date there have been no confirmed exomoon detecti ...

candidates around 8 exoplanets, but some researchers have considered that such satellites would be logical places for life to exist around giant gaseous worlds that otherwise could not be expected to support biology. Models indicate that TrES-1 has undergone significant tidal heating in the past due to its eccentric orbit, but this does not appear to have inflated the planet's radius.

References

External links

AAVSO Variable Star Of The Season. Fall 2004: The Transiting Exoplanets HD 209458 and TrES-1
* * * * * {{DEFAULTSORT:Tres-1 Hot Jupiters Lyra (constellation) Transiting exoplanets Exoplanets discovered in 2004 Giant planets