News| Politics| | Advert| Pageantry| Entertainment | Sport | Lifestyle | Fashion | Inspiration | & Health.
VAIDS
Thursday, November 6, 2014
Planet formation captured in Photo
The clearest ever image of planets forming around an
infant star has been taken by the Alma radio telescope.
In a vast disc of dust and gas, dark rings are clearly visible: gaps in
the cloud, swept clear by brand new planets in orbit.
The sun-like star at the centre, HL Tau, is less than a million years
old and is 450 light years from Earth in the constellation Taurus. The image was made possible by Alma's new high-resolution capabilities.
A protoplanetary disc has formed around the young star HL Tau
Because the process of planet formation takes place in the midst of
such a huge dust cloud, it can't be observed using visible light.
Alma, the Atacama Large Millimeter/submillimeter Array, has snapped the
impressive new image using much longer wavelengths, which it detects by
comparing the signal from multiple antennas up to 15km apart.
To test out its latest high-resolution capability, only in operation
since September, Alma scientists pointed the antennas at HL Tau. They found
themselves looking at a "protoplanetary disc" in more detail than
ever before.
"I think it's phenomenal," said Dr Aprajita Verma, an
astrophysicist at the University of Oxford.
"This shows how exciting Alma is going to be - it's going to be an
incredible instrument."
Prof Tim de Zeeuw is director general of the European Southern
Observatory, one of several organisations involved in Alma. He said: "Most
of what we know about planet formation today is based on theory. Images with
this level of detail have up to now been relegated to computer simulations or
artist's impressions."
Dr Verma agreed that the image was a significant new piece of evidence
- particularly because the star HL Tau is very young.
"I think the big result is that you might have expected just a
smooth disc," she told the BBC.
"But you're really seeing multiple rings - and where it's darker,
that's where you've cleared the material already in the disc."
The whole process is happening faster than we would have predicted from
existing data, Dr Verma explained.
"It means that things are coagulating. It's really a planetary
system, that you're seeing at a very early time.
"These rings will form planets, asteroids, comets... And
eventually as the star evolves, this will cool and settle and there will be
more clearing and more individual objects, just like we see in our solar
system."
No comments:
Post a Comment