Scientists discover Flabbergasting Gas Giant.

Having discovered all the planets in our own solar system astronomers are now interested in discovering planets in other systems. Georgi Mandushev, an astronomer from Lowell Observatory, is one of the leading astronomers on the prowl. He is part of a team working on the Transatlantic Exoplanet Survey (TrES).
Mandushev has always been interested in the mid-night sky. “When I was child, astronomy was hobby of mine,” Mandushev said, “as I grew up I realized I was also good at math and science so I decide to combine my passion with my knowhow, and an astronomer is what I became.
In 2003, scientists found their first transient planet.”It’s hard to find transient planets because in order for us to see them our line of site has to view the planet revolve horizontally around its host star,” Mandushev said. “If the planet revolves vertically our instruments will never detect it.” planetary transits are only observable for planets whose orbits happen to be perfectly aligned from astronomers' field of view. This leaves only about ten percent of all transits able to be detected.
For the last five years, Mandushev and other scientists have been pointing their equipment at far off stars in hopes of finding planets like the ones in Earth’s solar system. “It’s hard to find rocky planets because they’re too small, so all we have yet to find are gas giants,” Mandushev said. Through the use of a network of three 10cm telescopes in Arizona, California and the Canary Islands, scientists are charting far off galaxies in hopes of discovering new planets.
“TrES—4 is one of 20 transiting planets that have been discovered using the transiting method,” Mandushev said. “A transiting planet passes directly between the Earth and the star, blocking some of the star's light and causing a slight drop in its brightness.” The average drop in brightness is usually 2 percent. Once the transiting method is used to detect light differentials of the host star, scientists then use the radial-velocity method to determine the velocity of the planet. As the planet revolves around the star it slightly pulls the star, which can be detected on Earth through the Doppler Effect. An observed red shift due to the Doppler effect occurs whenever a light source moves away from the observer where as a blue shift happens when the light source moves towards the observer. Knowing how big a star is and how long it takes to revolve around the star gives scientist clues as to how fast the star moves.
TrES—4 is a gas giant that resembles Jupiter, but is 70 percent larger then Jupiter. The planet was discovered when astronomers pointed their equipment into the constellation of Hercules on Aug. 2, 2007. “Our equipment examines over 50 thousand stars in one view,” Mandushev said. “Of all those stars only about 150 of them are candidates, and most turn out to be duds.” Scientists determine if a star has a transiting planet by the fluctuation in light as the planet crosses in front of the star and the telescopes’ field of view. When astronomers are reviewing the data, they are looking at thousands of dots and zeroing in on a slight differense in brightness.
“TrES—4 is the biggest planet that we have found so far,” Mandushev said. “In fact its discovery may lead to new gas giant models.” The mostly hydrogen planet has the largest radius and lowest density of any of the known transiting planets. Mandushev has written in the Astrophysics Journal, Oct. 1, 2007, that some scientists propose that the planet is able to be big with a low density because it may be composed of different heat sources, or that the planet has an extended outer atmosphere caused by blow off of atmospheric material.
It is theorized that the planet leaves a comet like residue as it revolves around its host star once every 3.55 days. The composition and size of the planet leaves more questions than answers. Scientists hope that as long as they keep surveying the night skies that they will keep being astonished and amazed. After all, is that not what all great discoverers hope for?