Newly Discovered Nearby Brown Dwarf is Coldest of Its Kind
Posted on April 25, 2014
Penn State University astronomer Kevin Luhman, using NASA's Wide-field Infrared Survey Explorer (WISE) and Spitzer Space Telescopes, has discovered a new brown dwarf star that is 7.2 light-years away. This makes it the fourth closest system to our Sun. The diagram below shows our Sun's closest neighbors:
The star, announced today in a NASA press release, also appears to be the coldest of its kind. The brown dwarf, named WISE J085510.83-071442.5, has a chilly temperature between minus 54 and 9 degrees Fahrenheit (minus 48 to minus 13 degrees Celsius). Previous record holders for coldest brown dwarfs were much warmer - around room temperature.
Kevin Luhman, an associate professor of astronomy and astrophysics at Penn State, said in the announcement, "It is very exciting to discover a new neighbor of our solar system that is so close. In addition, its extreme temperature should tell us a lot about the atmospheres of planets, which often have similarly cold temperatures."
The star may not make not make a great destination for future space travel (once we are willing and able to travel over 7 light-years) as the planets around it are likely to be very cold.
Luhman says, "Any planets that might orbit it would be much too cold to support life as we know it."
WISE J085510.83-071442.5 has a mass that is estimated to be 3 to 10 times the mass of Jupiter. Scientists say it is possible the object is a gas giant like Jupiter that was ejected from its star system, but it is most likely a brown dwarf. If it is a brown dwarf then it is one of the least massive brown dwarfs found to date.
The gas giant or star was located by using WISE to scan the entire sky in infrared light multiple times. The weak thermal glow of brown dwarfs is difficult to spot with visible light telescopes, but stands out in infrared light. Luhman noticed the that the object appeared to move fast in the WISE data and then analyzed additional images taken with Spitzer and the Gemini South telescope on Cerro Pachon in Chile to identify the brown dwarf and determine its temperature range.