APOD: PDS 70: Disk, Planets, and Moons (2021 Aug 24)

Comments and questions about the APOD on the main view screen.
User avatar
APOD Robot
Otto Posterman
Posts: 4438
Joined: Fri Dec 04, 2009 3:27 am

APOD: PDS 70: Disk, Planets, and Moons (2021 Aug 24)

Post by APOD Robot » Tue Aug 24, 2021 4:05 am

Image PDS 70: Disk, Planets, and Moons

Explanation: It's not the big disk that's attracting the most attention. Although the big planet-forming disk 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 itself a dusty disk that is now forming into moons -- and that has never been seen before. The featured image was taken 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.

<< Previous APOD This Day in APOD Next APOD >>

User avatar
XgeoX
Science Officer
Posts: 113
Joined: Tue Jun 30, 2020 12:57 pm
AKA: Idiot

Re: APOD: PDS 70: Disk, Planets, and Moons (2021 Aug 24)

Post by XgeoX » Tue Aug 24, 2021 8:34 am

I’m curious if that slight bulge and dot at the 12:30 position on the star is another planet or if it’s just a processing artifact.
Also it’s really impressive how sharp the ALMA image is compared to the visual light one.

Eric

Eclectic Man
Ensign
Posts: 34
Joined: Thu May 20, 2010 8:46 pm

Re: APOD: PDS 70: Disk, Planets, and Moons (2021 Aug 24)

Post by Eclectic Man » Tue Aug 24, 2021 10:13 am

Can I assume that the reason the planet, PDS 70c and the ring are shown as brighter in the image than the central star, PDS 70, is that the image has been processed to reduce the star's brightness so that the other elements of the image are not overwhelmed?

User avatar
RJN
Baffled Boffin
Posts: 1607
Joined: Sat Jul 24, 2004 1:58 pm
Location: Michigan Tech

Re: APOD: PDS 70: Disk, Planets, and Moons (2021 Aug 24)

Post by RJN » Tue Aug 24, 2021 11:38 am

The credit line under the image was partly incorrect and has been updated. The new credit line reads:
ALMA (ESO/NAOJ/NRAO); M. Benisty et al.
We apologize for the oversight.
- RJN

User avatar
orin stepanek
Plutopian
Posts: 6881
Joined: Wed Jul 27, 2005 3:41 pm
Location: Nebraska

Re: APOD: PDS 70: Disk, Planets, and Moons (2021 Aug 24)

Post by orin stepanek » Tue Aug 24, 2021 11:54 am

PDS70_ALMA_1237.jpg
Wow; amazing that we can have privy to photos that
show stars and planets and moons being formed! I
wonder how many more planets are being formed
around this star that we can't even see right now! I
loved the write-up for today's APOD; I could spend a lot
of time on it!
animals-looking-through-the-window-201.jpg
Wow guys; better than television!
You do not have the required permissions to view the files attached to this post.
Orin

Smile today; tomorrow's another day!

Guest

Re: APOD: PDS 70: Disk, Planets, and Moons (2021 Aug 24)

Post by Guest » Tue Aug 24, 2021 1:31 pm

How do we know that it is a moon forming versus a moon breaking up?

E Fish
Science Officer
Posts: 118
Joined: Thu Mar 09, 2017 2:29 pm

Re: APOD: PDS 70: Disk, Planets, and Moons (2021 Aug 24)

Post by E Fish » Tue Aug 24, 2021 1:47 pm

This is really amazing. I still remember when I read an article about the first five exoplanets ever discovered, all several times larger than Jupiter. I can't believe how much more we have seen since then.

User avatar
Chris Peterson
Abominable Snowman
Posts: 16174
Joined: Wed Jan 31, 2007 11:13 pm
Location: Guffey, Colorado, USA

Re: APOD: PDS 70: Disk, Planets, and Moons (2021 Aug 24)

Post by Chris Peterson » Tue Aug 24, 2021 2:42 pm

Eclectic Man wrote:
Tue Aug 24, 2021 10:13 am
Can I assume that the reason the planet, PDS 70c and the ring are shown as brighter in the image than the central star, PDS 70, is that the image has been processed to reduce the star's brightness so that the other elements of the image are not overwhelmed?
I think that the planet and the dust disc are intrinsically much brighter than the star at the millimeter/submillimeter imaging wavelengths.
Chris

*****************************************
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

Avalon

Re: APOD: PDS 70: Disk, Planets, and Moons (2021 Aug 24)

Post by Avalon » Tue Aug 24, 2021 4:25 pm

I would think that the star PDS 70 would be far brighter than the forming planet or moons.

User avatar
Chris Peterson
Abominable Snowman
Posts: 16174
Joined: Wed Jan 31, 2007 11:13 pm
Location: Guffey, Colorado, USA

Re: APOD: PDS 70: Disk, Planets, and Moons (2021 Aug 24)

Post by Chris Peterson » Tue Aug 24, 2021 4:32 pm

Avalon wrote:
Tue Aug 24, 2021 4:25 pm
I would think that the star PDS 70 would be far brighter than the forming planet or moons.
Not brighter at 1mm wavelength. The dust absorbs short wavelength radiation from the star and re-radiates it as long wavelength radiation.
Chris

*****************************************
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

User avatar
neufer
Vacationer at Tralfamadore
Posts: 18450
Joined: Mon Jan 21, 2008 1:57 pm
Location: Alexandria, Virginia

Re: APOD: PDS 70: Disk, Planets, and Moons (2021 Aug 24)

Post by neufer » Tue Aug 24, 2021 6:45 pm

Chris Peterson wrote:
Tue Aug 24, 2021 4:32 pm
Avalon wrote:
Tue Aug 24, 2021 4:25 pm

I would think that the star PDS 70 would be far brighter than the forming planet or moons.
Not brighter at 1mm wavelength. The dust absorbs short wavelength radiation from the star and re-radiates it as long wavelength radiation.
The planet PDS 70b also absorbs short wavelength radiation from the star and re-radiates it as long wavelength radiation. However, unlike PDS 70c, PDS 70b is NOT present in the ALMA image indicating that the intensity of PDS 70b and everything interior to it have been significantly suppressed.
https://www.youtube.com/watch?v=ZmUCm1O1vuY wrote: <<This spectacular image from the SPHERE instrument on ESO's Very Large Telescope is the first clear image of [PDS 70b] caught in the very act of formation around the dwarf star PDS 70. The planet stands clearly out, visible as a bright point to the right of the centre of the image, which is blacked out by the coronagraph mask used to block the blinding light of the central star.>>
Art Neuendorffer