Some Interesting Exoplanets

TrES-4 was discovered when looking for transiting planets. It is about 70 percent bigger than Jupiter but less massive. TrES-4 has the density of approximately 0.2 grams per cubic centimeter, or that of balsa wood.The Gliese 581 System is a red dwarf star with a mass about 1/3 that of the Sun. It is located 20.4 light years from Earth and is among the 100 closest stars to Earth. Gliese 581 has at least four planets:

  • Gliese 581b: ~16X as massive as Earth and completes one orbit of Gliese 581 in 5.4 days; appears to be Neptune-like
  • Gliese 581c and g: rocky planets; Gliese 581c appears to be in the Goldilocks Zone
  • Gliese 581d: ~8X as massive as Earth; orbits Gliese 581 in 84 days

HD80606b is a strange planet about four times the mass of Jupiter. It comes so close to its star, at its perihelion point HD80606b would have a surface temperature of 1,200oC.

Then there is the strange planet, Wasp-12b . It takes this planet 1.1 earth days to go around its star one time; in other words, you would celebrate your birthday every 26.4 hours. Wasp-12b’s surface temperature is estimated to be 1,500oC, and it is slowly being eaten by its star.

Stellar System Stars and Life

When considering life, one must look at the type of star as well as the question of planets and the type of planet(s). Of the closest 1,000 stars, only one matches the Sun’s temperature, size, and brightness (called luminosity). It is the star Alpha Centauri.

Many biologists and astronomers believe that you have to have the right type of star, as well as the right type of planet, and the right distance from its star for intelligent life.