An image taken using the Atacama Large Millimeter /submillimeter Array in Chile and released in 2014 shows something rather special. It’s a disc, taken from an angle, with concentric striations. At the centre is the very young star HL Tau, just a million years old, 450 light-years from Earth in the constellation of Taurus. The striated disc is the protoplanetary disc of dust and gas, coalescing into a planetary system around HL Tau.
The gaps in the disc are thought to have been cleared by larger planetary bodies in the dust. The ALMA study was the clearest view yet of this long-theorised process.
However, while ALMA could see more detail in the outer disc, the inner dusty regions were opaque to ALMA’s sensors. So an international team of scientists used the Karl F Jansky Very Large Array radio telescope located in New Mexico. The VLA is capable of detecting longer wavelengths than ALMA, and could view the inner ring in finer detail.
And it found something. Close to the star, VLA found a clump in the innermost region of the disc, sized at roughly three to eight times the size of the earth. A baby planet.
“We believe this clump of dust represents the earliest stage in the formation of protoplanets, and this is the first time we’ve seen that stage,” said study co-leader Thomas Henning of the Max Planck Institute for Astronomy in a statement.
Planets are a lot harder to study than stars, because they do not give off any visible light or radiation on their own. We can only study them based on reflected or absorbed and re-emitted radiation from stars, which is a lot weaker than what the stars themselves give off. Viewing a planet directly is very rare, and a protoplanet even rarer.
Click here to read more.
SOURCE: Cnet, Michelle Starr