Like anything that grows, baby stars need to eat. In this case, their food source has been dubbed a space hamburger, a flat thick disk of material predicted to form during the stars' earliest years. Finding these space hamburgers has not been easy, but astronomers have harnessed the power of the most advanced telescopes to finally spot one.
In a paper published in Science Advances, researchers describe the disk of material surrounding HH 212, a young protostellar system 1,300 light-years from Earth. The star is about 40,000 years old and sports an impressive jet of material escaping the system.
Previous searches had hinted at the existence of a small dusty disk near the protostar, so the research team led by Dr Chin-Fei Lee from the Academia Sinica Institute of Astronomy and Astrophysics used the Atacama Large Millimeter/submillimeter Array (ALMA) to get a better look at the baby star.
ALMA has 25,000 times higher resolution than previous observatories, so astronomers were able to obtain more detail of the dusty disk surrounding HH 212. The disk is nearly edge-on and has a radius of 60 astronomical units (AU), with one AU being the distance between the Earth and the Sun. Neptune is about 30 AU from the Sun.
Astronomers have long suspected the existence of these disks, and this discovery brings some much-needed observations to compare models against. As predicted, the disk is flared in the middle from the emission of the star.
Being almost edge on, it shows a prominent dark lane between two lighter and shorter features. No surprise, people think it looks like a burger. The difference in color depends on differences in how thick the gas and dust in the disk are and also due to different temperatures, with dark being relatively colder. The disk goes from a few to a few tens of degrees above absolute zero.
The discovery is really important to explain how stars mature and how stellar systems, like ours, come to form. According to some theories, the formation of disks is hindered by stars’ magnetic fields, but it doesn’t seem to be the case in this instance. If HH 212 turns out to be the rule rather than the exception, this will lead to a significant revision of our ideas of planetary formation.