Accretion disk images guide theories on planet formation

quantamagazine.org

58 points·MeteorMarc··7 comments

More images of young stars with their accretion disk can be found at: https://public.nrao.edu/news/2018-alma-survey-disks/

Those are absolutely breathtaking. I never thought I'd see images like this with such clarity.

I just read they're the result of 66 dishes aimed at the sky. Do they also use the Earth's position around the sun 6 months apart, or are these images created with relatively short observations?

In interferometry [0], you need your telescope components to be collecting data simultaneously so that you can interfere their collected light together - so the maximum possible separation is about the diameter of the Earth. (The VLBA [1] and the EHT [2] make use of most of this potential.)

There have been proposals to extend this maximum baseline by having space-borne interferometers (perhaps orbiting the Sun), but practically, they are a few decades away at best. [3]

[0] https://en.wikipedia.org/wiki/Astronomical_interferometer

[1] https://en.wikipedia.org/wiki/Very_Long_Baseline_Array

[2] https://en.wikipedia.org/wiki/Event_Horizon_Telescope

[3] https://www.noao.edu/meetings/interferometry/workshop-files/...

Ah yes. I confused two different ideas. Thanks for the links

Skimming through the pre-print (https://arxiv.org/pdf/1812.04040.pdf), it doesn't look like they're using the Earth's position along the orbit.

Looks like on the order of ~hour per target.

Thank you

Simply unbelievable what we are able to observe on Earth.

Imagine a cork bobbing in the ocean, how much information about the entire ocean could it derive from what it can see and hear? And the Earth is smaller in the universe than a cork in the ocean, think about how much out there we can't even perceive from our little corner.

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