Astronomers Spot Star in Protoplanetary Disk Region That Appears Abnormally ColdBy Russell Westerholm, UniversityHerald Reporter
Astronomers discovered an uncommonly cold protoplanetary disk with a relatively young star.
According to Space.com, the astronomers spotted a star they named 2MASS J16281370-2431391 about 400 light years from Earth. Its position in the disk appears to be ideal for new planets to form.
"This disc is not observed against a black and empty night sky. Instead it's seen in silhouette in front of the glow of the Rho Ophiuchi Nebula," Stéphane Guilloteau, of France's Laboratoire d'Astrophysique de Bordeaux, said in a press release. "This diffuse glow is too extended to be detected by ALMA, but the disc absorbs it. The resulting negative signal means that parts of the disc are colder than the background. The Earth is quite literally in the shadow of the Flying Saucer!"
The researchers spotted the star with the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile and calculated the surrounding temperature to be -447 degrees Fahrenheit. The extremely low temperatures could give astronomers cause to reexamine how planet's form.
"To work out the impact of this discovery on disc structure, we have to find what plausible dust properties can result in such low temperatures," Emmanuel di Folco, also of France's Laboratoire d'Astrophysique de Bordeaux, said in the release. We have a few ideas - for example the temperature may depend on grain size, with the bigger grains cooler than the smaller ones. But it is too early to be sure."