Baby Star Has Planet-Forming Disk That Confounds Scientists

Astronomers have been studying something far away from the Earth in the Rho Ophiuchi star formation region. Inside this region is a very young star known as 2MASS J16281370-2431391 that is about 400 light years away from Earth. This infant star has a planetary formation disk around it that is disk edge on to us here on Earth.

The disk edge view allows the astronomers to see a glowing halo with a dark band in the middle around the star and that dark band is surprising. The look of the disk has earned the star the nickname "Flying Saucer." When astronomers were studying the Flying Saucer using the Atacama Large Millimeter Array (ALMA) in Chile and ITAM 30-meter telescope in Spain they found something very different about the protoplanetary disk around the star.

Parts of that protoplanetary disk are colder than the glowing background of the Rho Ophiuchi Nebula. The team of astronomers was able to carry out the first direct measurements of larger grains of dust in the Flying Saucer. These grains of dust measure about one millimeter across and have reached a low temperature of -266 degrees Celsius.

Current models predict that the dust should be somewhere in the realm of -258 to -253 degrees Celsius, about 10-15 degrees above absolute zero. What sounds like a minor change is actually a huge change in scientific terms. Scientists are studying the temperature discrepancy because temperature of the dust has a big impact on the size and developmental characteristics of the planets that will eventually form around the star. Cooler dust allows for larger planets to form. Scientists plan to study similar protoplanetary discs around other stars to see if similar temperatures are observed.

SOURCE: Discovery