This APOD image is a good one. Usually images these are shown in black and white, this is false colour. But everything is these days.

PDS 70: Disk, Planets, and Moons Image Credit: ALMA (ESO/NAOJ/NRAO); M. Benisty et al.

Explanation: It’s not the big ring that’s attracting the most attention. Although the big planet-forming ring around the star PDS 70 is clearly imaged and itself quite interesting. It’s also not the planet on the right, just inside the big disk, that’s being talked about the most. Although the planet PDS 70c is a newly formed and, interestingly, similar in size and mass to Jupiter. It’s the fuzzy patch around the planet PDS 70c that’s causing the commotion. That fuzzy patch is thought to be a dusty disk that is now forming into moons — and that had never been seen before. The featured image was taken in 2021 by the Atacama Large Millimeter Array (ALMA) of 66 radio telescopes in the high Atacama Desert of northern Chile. Based on ALMA data, astronomers infer that the moon-forming exoplanetary disk has a radius similar to our Earth’s orbit, and may one day form three or so Luna-sized moons — not very different from our Jupiter’s four.

Not that long ago, astronomers would have been astonished by this level of detail.

mollwollfumble said:

This APOD image is a good one. Usually images these are shown in black and white, this is false colour. But everything is these days.

PDS 70: Disk, Planets, and Moons Image Credit: ALMA (ESO/NAOJ/NRAO); M. Benisty et al.

Explanation: It’s not the big ring that’s attracting the most attention. Although the big planet-forming ring around the star PDS 70 is clearly imaged and itself quite interesting. It’s also not the planet on the right, just inside the big disk, that’s being talked about the most. Although the planet PDS 70c is a newly formed and, interestingly, similar in size and mass to Jupiter. It’s the fuzzy patch around the planet PDS 70c that’s causing the commotion. That fuzzy patch is thought to be a dusty disk that is now forming into moons — and that had never been seen before. The featured image was taken in 2021 by the Atacama Large Millimeter Array (ALMA) of 66 radio telescopes in the high Atacama Desert of northern Chile. Based on ALMA data, astronomers infer that the moon-forming exoplanetary disk has a radius similar to our Earth’s orbit, and may one day form three or so Luna-sized moons — not very different from our Jupiter’s four.

Wow

dv said:

mollwollfumble said:

This APOD image is a good one. Usually images these are shown in black and white, this is false colour. But everything is these days.

PDS 70: Disk, Planets, and Moons Image Credit: ALMA (ESO/NAOJ/NRAO); M. Benisty et al.

Explanation: It’s not the big ring that’s attracting the most attention. Although the big planet-forming ring around the star PDS 70 is clearly imaged and itself quite interesting. It’s also not the planet on the right, just inside the big disk, that’s being talked about the most. Although the planet PDS 70c is a newly formed and, interestingly, similar in size and mass to Jupiter. It’s the fuzzy patch around the planet PDS 70c that’s causing the commotion. That fuzzy patch is thought to be a dusty disk that is now forming into moons — and that had never been seen before. The featured image was taken in 2021 by the Atacama Large Millimeter Array (ALMA) of 66 radio telescopes in the high Atacama Desert of northern Chile. Based on ALMA data, astronomers infer that the moon-forming exoplanetary disk has a radius similar to our Earth’s orbit, and may one day form three or so Luna-sized moons — not very different from our Jupiter’s four.

Wow

Yes. It is all amazing stuff.

roughbarked said:

dv said:

mollwollfumble said:

This APOD image is a good one. Usually images these are shown in black and white, this is false colour. But everything is these days.

…

Wow

Yes. It is all amazing stuff.

The weirdest thing for me is that this was detected by ALMA. How can a radio telescope see planetary systems, the wavelength range is wrong, you need thermal infrared.

So it seems that my preconceptions are wrong.

From https://www.eso.org/public/teles-instr/alma/receiver-bands/

The Atacama Large Millimeter/submillimeter Array (ALMA) observes the Universe over a range of radio wavelengths within the millimetre and submillimetre region of the electromagnetic spectrum. To capture such a broad range of light from distant cosmic sources, each of ALMA’s 66 antennas are equipped with an arsenal of detectors, which are highly sensitive radio receivers. Each receiver type is sensitive to a particular “band”, or range of wavelengths of the electromagnetic spectrum, and data can only be taken in one band at a time.

To date, eight out of a planned ten receivers have been installed on each ALMA antenna. These bands range from band 3, starting at wavelengths of 3.6 mm, to band 10, ending at 0.3 mm.

The average temperature of Pluto is 44 Kelvin.
Detectable from ALMA band 2.

The average temperature of Saturn is about 140 Kelvin.
Detectable from ALMA band 6.

So temperatures of cold planetary systems really are slap bang in the middle of radio telescope capabilities. It doesn’t even need the sub mm capabilities of ALMA band 10 which is centred near a temperature of 344 Kelvin.

It doesn’t surprise me TOO much that radio telescopes are capable of this level of precision. Radio telescope arrays have had an angular precision better than that of the Hubble telescope even as far back as the year 2000, if not earlier.

It is still extremely impressive.