There’s a taste of the sublime in the photograph of this extrasolar worldby Philip Ball / July 3, 2018 / Leave a comment
Just occasionally, the astronomical sciences come up with sights that ought to awaken even in the most dulled sensibility a hint of Edmund Burke’s notion of the Sublime. If, as Burke said, such feelings stem from a sense of danger abrogated by distance and transformed into beauty, the live telescope imagesof comet Shoemaker-Levy 9 crashing into Jupiter and leaving an Earth-sized hole in 1994 did it for me.
There’s a little taste of the same in the image just released by a team of astronomers of a planet in the throes of being born around another star.
Sure, we already knew that “extrasolar” planets exist—there’s now a catalogue of thousands of them, seen mostly from the periodic, tiny dip in their parent star’s light as the planet passes in front of it, or from the wobble that a large enough planet induces in the star. We can deduce the masses, sizes and positions of these planets, and thereby have a sense of the tremendous diversity of other worlds beyond our solar system. We’ve even been able to measure the reflected light from a few such planets.
But the object now seen by a team led by astronomers at the Max Planck Institute for Astronomy in Heidelberg, using a telescope at the European Southern Observatory (ESO) in Chile, is something else. It’s a planet in the process of formation, and the researchers have actually captured an image of it: a bright blob in the disk of hot gas and dust around a young dwarf star called PDS 70, in the constellation of Centaurus 370 light years away. We’re literally watching worlds in the making.
For our own solar system, this process happened about four and a half billion years ago. A star will condense out of a cloud of interstellar gas and dust under the pull of its own gravity. The material falling inwards gets denser and hotter until eventually it ignites the process of nuclear fusion that will keep the star glowing for billions of years.
“We can see a solar system taking shape, its planets starting to emerge from the chaos”
During that collapse, material surrounding the central core becomes spun into a disk: the raw material of a planetary system. This too will gradually become clumpy as gravity concentrates…