AS 805 Pavo: Two hundred galaxies

[Placidus]

Here is Abell South 805 in Pavo: the Placidus Deep Field.

16.5 hours Luminance (33 x 30 min) all from this New Moon, plus 15 hours total RGB, about half from this new moon and half from 2018.

The thumbnail is a tight crop on the main cluster members. The full field is here (https://photos.smugmug.com/Category/Astrophotography-at-Placidus/i-TPDMWTs/0/963e2d53/O/AS%20805%20with%20200%20galaxies%20-%20Lum%2016h30%20RGB%2016h%20total. jpg).

In the full frame we've arrowed some 200 objects that we felt were either definite or highly probable galaxies based on their morphology, stopping at the point where we've probably falsely labelled a couple stars, and missed a couple real ones. No attempt has been made to distinguish cluster members from line of sight background fellows, but you can probably get a good idea by just eyeballing.

The cluster is dominated by a huge elliptical galaxy, showing as a warm homogenous orange, because it has used up all its star-forming gas, and all the short-lived hot young blue stars are long gone.

Compare with the gorgeous face-on spiral showing intense star formation in the spiral arms at 11 o'clock in the thumb, with hot young blue stars a-plenty, especially in the upper spiral arm.

At the seven o'clock edge of the thumb is a side-on spiral, with a strong boxy "X"-shape in the core indicating the presence of a central bar.

Toward ten o'clock and 12 o'clock edges of the thumb are two bluish tidally distorted galaxies.

In the full image, toward the top right corner, is an unmistakeable StarShip Enterprise.

Toward the 10 o'clock edge of the full frame is a very faint but blue and featureless galaxy, which may perhaps be a foreground dwarf.

FLI PL16803 on 20 inch PlaneWave CDK. All robotics hardware, scope control, and image processing software built/written in house by us.

Best,
Mike and Trish

[multiweb]

Very cool. Like a Hubble deep field. :thumbsup: There are some severely disrupted pairs in the fov and some are so irregular they look like a splat on a wall.

[peter_4059]

Great stuff M&T. I really like these deep field images. So many galaxies!

[Andy01]

Fantastic result guys, a simply wonderful image - love it! :thumbsup::thumbsup::thumbsup:

[Placidus]

Thanks Marc. I reckon the dwellers in those irregular blob galaxies will have sleepless nights now.





Aye, Peter, to think that a typical galaxy has say 200 billion stars, and there are 200 obvious galaxies in the image. That's 40 trillion stars.





Thanks Andy! We are greatly encouraged. Going up to the observatory this morning before dawn to collect the booty, temperature 1.5 degrees, even in a freezer suit, gloves, and furry hat, was the hardest bit of all.


Best,
MnT

[alpal]

Hi Mike and Trish,
Amazing picture -so many galaxies.
I can't find the Star Ship Enterprise -

but I'm sure Captain Kirk is there somewhere. :)



cheers
Allan

[Placidus]

Thanks Allan,
Trish meant the emblem, the thing on their uniform. I wrote the starship. My bad. But it's a bit blurry, due to the jump to light speed, and it could plausibly be either.

[alpal]

OK - it's also been found on Mars:


https://petapixel.com/2019/06/15/nasa-finds-star-trek-starfleet-logo-on-mars/




:)

[Placidus]

Thought I'd seen it somewhere before.

While we're being whimsical, a thought about elliptical galaxies. They look all quiet and boring, lifeless even, because star formation has ceased. No harsh ultraviolet light from young suns to get life going. But perhaps they are exactly the right place for old farts to live in comfort, without getting shredded by supernovas.

[marc4darkskies]

Wow! What a great image M&T! :thumbsup::thumbsup::thumbsup: Definitely inspires the imagination!

[Placidus]

Thanks Marcus. Much appreciated.

[multiweb]

It is too. The federation galaxy. ;)

[Bart]

Lovely stuff. :eyepop:



Can we see the Placidus Deep Field without all the little arrows, please?

[Peter Ward]

A long time ago in a galaxy far, far away....

Stuff to inspire....wonderful. :thumbsup:

[strongmanmike]

Excellent galaxy shot guys, I recall the 2018 shot too :thumbsup:

Galaxy cluster shopts are just so intriguing especially whne they have such a mix of shapes.

There is a serious amount of galactic cirrus in front of this cluster, can you see it in your Lum? :)

Mike

[Slawomir]

Wonderful inspiring image Mike and Trish. Love it!

Last night I finished collecting data for the cat's paw and after seeing your extra deep field image, I thought I should try something similar in the near future, weather permitting. I didn't count the arrows, but I am proposing with 99% confidence level that there are still many more galaxies in your image :thumbsup:

[Placidus]

:thumbsup:


Thanks Bart. We've used tweezers to pull out all the little arrows. Will upload it tomorrow.





Thanks Peter! Most encouraging.





Thanks Mike :hi:We can indeed see the cirrus. It came out quite well. We'll prepare a version just to show that.





Thanks so much Suavi. Your cat's paw was very special.


Be safe everyone.
Mike and Trish

[Atmos]

I didn't go around and count them all but damn there is a lot of arrows you've added in there M&T :)
It's an exceptional image, well processed and leaves us with a sense of smallness in the universe :)

[gregbradley]

Gee M and T I only count 199. errh joking. Wonderful deep shot. These galaxy chain images are really popular shots and remind us just how much stuff there is in the Universe. Unimaginably large amounts of stuff.

Greg.

[codemonkey]

So many little fuzzies! Super cool image, guys, thanks for sharing!

[Ryderscope]

A superb collection of ‘galactic’ proportions. Simply stunning to behold.

[Paul Haese]

I reckon there are a heap of red shifted galaxies in there too Mike. Great colour and an image at depth. Nice going.

[rustigsmed]

not sure how i missed this one.

I really enjoyed scrollingaround the field and checking out the galaxies on my CX 77" oled.

do you have any idea what magnitude you got down to for this? so many ultra faint objects.

cheers

russ

[Joshua Bunn]

These shots are my favourite. You have done a fine job IMO. I have some data on this on to.

[Placidus]

Whoops! Sorry for late reply: people are posting good new images so thick and fast this one disappeared off the screen.















Thanks so much everyone! We agree wholeheartedly with the general sentiment that Space is Big and We are Tiny. One thinks of what must happen to the locals when two galaxies collide.

Wikipedia suggests a 10 metre scope has a limiting magnitude of 27 per hour of exposure, assuming very dark sky. So a 0.5 metre telescope under similar conditions but 16.5 times more exposure, the signal to noise ratio might be about 5 times less than the big scope, giving about 1.7 mags worse, say 25 mags limiting if shooting in the Atacama. But we have far worse skies here. Ridiculously so.

Anyone know a good formula?

[lazjen]

Can't help you with the formula, but I give this at least 2 :thumbsup: :)