Starship Asterisk*

[quote="Chris Peterson" post_id=316075 time=1629822743 user_id=117706]
[quote=Avalon post_id=316074 time=1629822344]

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

Not brighter at 1mm wavelength. The dust absorbs short wavelength radiation from the star and re-radiates it as long wavelength radiation.[/quote]
[b][u]The planet [color=#FF0000]PDS 70b[/color] also absorbs short wavelength radiation[/u][/b] from the star and re-radiates it as long wavelength radiation. However, unlike [b][color=#0000FF]PDS 70c[/color], [color=#FF0000]PDS 70b[/color] is [u]NOT present in the ALMA image[/u] indicating that [u]the intensity of [color=#FF0000]PDS 70b[/color] and everything interior to it have been significantly suppressed[/u][/b].

[quote=https://www.youtube.com/watch?v=ZmUCm1O1vuY]

[float=left][img3=Near IR image of PDS 70b with PDS 70 suppressed]https://upload.wikimedia.org/wikipedia/commons/1/1c/PDS_70.jpg[/img3][/float]

<<This spectacular image from the SPHERE instrument on ESO's Very Large Telescope is the first clear image of [[b][color=#FF0000]PDS 70b[/color][/b]] 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.>>[/quote]

[quote=Avalon post_id=316074 time=1629822344]
I would think that the star PDS 70 would be far brighter than the forming planet or moons.
[/quote]

Not brighter at 1mm wavelength. The dust absorbs short wavelength radiation from the star and re-radiates it as long wavelength radiation.

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

[quote="Eclectic Man" post_id=316065 time=1629800010 user_id=129639]
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?
[/quote]

I think that the planet and the dust disc are intrinsically much brighter than the star at the millimeter/submillimeter imaging wavelengths.

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.

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

[attachment=1]PDS70_ALMA_1237.jpg[/attachment]
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!
[attachment=0]animals-looking-through-the-window-201.jpg[/attachment]
Wow guys; better than television!

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

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’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

[url=https://apod.nasa.gov/apod/ap210824.html] [img]https://apod.nasa.gov/apod/calendar/S_210824.jpg[/img] [size=150]PDS 70: Disk, Planets, and Moons[/size][/url]

[b] Explanation: [/b] It's not the big disk that's attracting the most attention. Although the big planet-forming disk around the star [url=https://youtu.be/Cslrr2koNvU]PDS 70[/url] is clearly imaged and itself quite interesting. It's also not the planet on the right, just inside the [url=https://apod.nasa.gov/apod/ap041019.html]big disk[/url], that’s being talked about the most. Although the planet [url=https://en.wikipedia.org/wiki/PDS_70]PDS 70[/url]c is a newly formed and, interestingly, similar in size and mass to [url=https://apod.nasa.gov/apod/ap190908.html]Jupiter[/url]. It's the fuzzy patch around the [url=https://exoplanets.nasa.gov/exoplanet-catalog/7414/pds-70-c/]planet PDS 70c[/url] that's [url=https://static.boredpanda.com/blog/wp-content/uploads/2014/09/animals-looking-through-the-window-201.jpg]causing the commotion[/url]. That fuzzy patch is thought to be itself a [url=https://www.eso.org/public/news/eso2111/]dusty disk[/url] that is now forming into moons -- and that has never been seen before. The [url=https://www.eso.org/public/images/eso2111b/]featured image[/url] was taken by the [url=https://en.wikipedia.org/wiki/Atacama_Large_Millimeter_Array]Atacama Large Millimeter Array[/url] (ALMA) of 66 [url=https://apod.nasa.gov/apod/ap140526.html]radio telescopes[/url] in the high [url=https://youtu.be/o5JfmFSBDgE]Atacama Desert[/url] of northern [url=https://en.wikipedia.org/wiki/Chile]Chile[/url]. Based on ALMA data, [url=https://ui.adsabs.harvard.edu/abs/2021arXiv210807123B/abstract]astronomers infer[/url] that the moon-forming exoplanetary disk has a radius similar to our Earth's orbit, and may one day form three or so [url=https://en.wiktionary.org/wiki/Luna#Proper_noun]Luna[/url]-sized moons -- not very different from our [url=https://solarsystem.nasa.gov/planets/jupiter/overview/]Jupiter[/url]'s [url=https://www.jpl.nasa.gov/images/the-galilean-satellites]four[/url].


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