14 DAY TRIAL // Astronomers believe they may have just imaged the first extrasolar planet featuring an Earth-like, temperate climate. Such conditions are a must for the development of life, in addition to the existence of liquid water and the presence of a magnetosphere.
Over the past couple of years, the number of exoplanets that are similar to our own in many regards has increased, and experts are convinced that a second Earth will be discovered soon. The new object, designated WD 0806-661b, may be an intermediary step towards achieving this objective.
Pennsylvania State University (Penn State) associate professor of astronomy and astrophysics Kevin Luhman says that the celestial body is in fact a brown dwarf, a failed star that could not achieve nuclear fusion when it coalesced from a massive cloud of molecular hydrogen gas.
Still, brown dwarfs as a class are larger than gas giants, a type of planet including Saturn and Jupiter. “This planet-like companion is the coldest object ever directly photographed outside our solar system,” the investigator explains.
“Its mass is about the same as many of the known extra-solar planets – about six to nine times the mass of Jupiter – but in other ways it is more like a star. Essentially, what we have found is a very small star with an atmospheric temperature about cool as the Earth's,” he goes on to say.
Investigations of WD 0806-661b revealed that brown dwarf is heated to only about 80 to 160 degrees Fahrenheit (26.6 to 71.1 degrees Celsius). This is well within the necessary range to support life. The planet may be too hot at times, but bacteria here on Earth are known to live at hundreds of degree.
This interesting brown dwarf orbits the white dwarf WD 0806-661. A white dwarf is the helium-burning remnant of a yellow star that reached the end of its burning cycle. The Sun will become a white dwarf too, after going through a red giant phase. This will occur about 4 to 5 billion years from now.
“The distance of this white dwarf from the Sun is 63 light years, which is very near our solar system compared with most stars in our galaxy,” Luhman explains, quoted by Daily Galaxy.
“The distance of this white dwarf from its brown-dwarf companion is 2500 astronomical units (AU) – about 2,500 times the distance between the Earth and the Sun, so its orbit is very large as compared with the orbits of planets, which form within a disk of dust swirling close around a newborn star,” Adam Burgasser adds.
The expert, who was a member of the discovery team, is based at the University of California in San Diego (UCSD). “Objects with cool temperatures like the Earth are brightest at infrared wavelengths,” Luhman explains.
“We used NASA's Spitzer Space Telescope because it is the most sensitive infrared telescope available,” he concludes.