NGC 5101, 5078, and friends in southern Hydra

[Placidus]

The delicate, bluish face-on tightly wound spiral is NGC 5101 in southern Hydra. The edge-on spiral with burnt-orange core threaded with branching dust lanes is NGC 5078. It itself has an evil companion which looks very like the meat-hook galaxy.

Compulsory link to original image here (www.mikeberthonjones.smugmug.com/Category/Astrophotography-at-Placidus/i-6Ch6rxZ/1/O/NGC%205101%20and%20friends%20L%207h rs%20RGB%202h30%20each.jpg)

There are hundreds of other galaxies near and far in the image, many showing clear spiral structure. There seems to be a very busy cluster of distant orange galaxies about 20% of the way toward 8 o'clock.

Lum: 7hrs in 1hr unbinned subs. RGB: 2.5 hrs each in 30 min unbinned subs.

Aspen CG16M on 20" PlaneWave. GoodLook 64.

We are very grateful that some much needed 40 mm of rain is coming to the thirsty central west (there's not so much feed left in many paddocks), but it means that further hours on this one will have to wait till next new moon.

Very best,
Mike and Trish

[el_draco]

Wow! What a gorgeous shot. :thumbsup: Love those faint galaxies al round the place.

[codemonkey]

Beautiful work! Lots of little fuzzies; enjoyed panning around in the full res.

[Atmos]

When I first looked at the high res my first words were wowza! What I like about all of those bright stars is that they ALL LOOK LIKEE THEY'RE EXPLODING!

Now that that is out of my system, it is a lovely imagine. I do particularly like that fainter galaxy cluster, it looks quite redshifted and quite distant!

[Shiraz]

Stunning part of the sky. Impressive star colour and essentially perfect processing of the galaxies. Another top image.

[Peter Ward]

Great result :thumbsup:

Reminds me of....

A fish.....swimming...somewhere..... ;)

[Placidus]

Thanks, Rom. There seems to be some sharp-edged patches of bluish nebulosity that we forgot to mention also.



Thanks, Lee. We enjoyed photographing this after 4945 in Centaurus, where it's far harder to find background galaxies.



Cheers, Colin. The exploding stars might be because we pushed the image quite hard. Or perhaps there was some loose spider-web making diffraction spikes. (Really). Hopefully it wasn't because we just washed the main mirror and left scratchy streaks!



Thanks, Ray. Thrilled that you like it.



Thank you Peter. Perhaps 5101 is benthic and 5078 is pelagic.

Best,
MnT

[RickS]

A great FOV, M&T. Some lovely galaxies, near and far!

Cheers,
Rick.

[Paul Haese]

MnT, I started this very same paring a couple of years ago now before I went to an AOX for guiding. I had about 10 hours of luminance at the time but never got the chance to get the colour as the camera died on me.

Your composition is 90 degrees to the way I was imaging it, it is different but interesting. Colour saturation looks good but not sure about the colour of 5078. Isn't that supposed to be a yellowy white colour? Smooth and silky finish though is quite pleasurable to see.

[Stevec35]

What a great field! I love what you guys do. Totally endorse your comments about the rain but lets hope it doesn't stay around for too long.

Steve

[plantnerd]

Wow so many different types of galaxy in the same spot. The top one looks like a mini SOmbrero should us Aussies christen in the Akubra Galaxy because it is Shouthern?

[Placidus]

Thanks, Rick. We puzzled about whether to present the two major galaxies as separate images, as the pair together don't really quite suit the FOV, or whether to make it a mosaic. But the de-militarized zone in the middle proves to be quite fascinating in its own right.



Cheers, Paul. That's kind. Sad about your camera.

We expected the centre of 5078 to be more of an orange-yellow, based on Martin Pugh's APOD and also an old David Malin AAO shot. Our colour processing plan is:

- Set provisional zero point to the foothill of the histogram on each channel.
- Lightly wavelet noise filter.
- Low-order background gradient removal. Fine checkerboard placed over image. Squares occupied by striking features deleted. Then use multiple linear regression on square-by-square median to remove gradient.
- Repeat zero point
- Arcsinh curve with slope of about 10 at origin
- Set image as a whole to be colour neutral (ie average colour is grey)
- Increase saturation till looks about right
- Repeat zero point, colour neutral balance, and final arcsinh curve.

So the idea is to produce an image that shows relative, rather than absolute colours. (Not suitable for RGB on nebulas, but we don't do those).

Perhaps if we do new flats (overdue for RGB), and do some additional panels more centered over the main galaxies, the colour will look more as expected, but on religious grounds we don't try hand-tweaking to produce a particular colour effect. More data can only help.



Thanks muchly Steve. Hope you guys get some brief soaking rain too.



Hi, Luis,

Akubra it is. There's a lot of southern constellations that need disassembling into smaller units for southern viewers. We call Chamaeleon "the Kite", and Apus (plus a bit of Octans) "The Mouse". Instantly recognizable.

I wrongly wrote 5078 was an edge-on spiral (we were thinking of 5128, an elliptical engulfing a spiral, and calling it not the Hamburger but the Hot Dog) but it is in fact a lenticular galaxy. I don't have much of a feel for the astrophysics of those.

Very best,
Mike

[rustigsmed]

wow cool capture M&T,
I like how you manage to squeeze these galaxies into the frame. great field.

russ

[Andy01]

Crikey!
I counted over 70 galaxies without even trying!

That's an astounding image - nothing wrong with your NB images but you guys should really do more of this amazing LRGB galaxy stuff, it's incredible :eyepop:

Very well done M&T :thumbsup:

[topheart]

Love it!
Great composition!
Thanks,
Tim

[strongmanmike]

Yeah I agree with Andy :D

Another great image to surf and the distant yellow galaxies are great features...I see a faint diffuse patch of something just left of centre...what do you recon that is?

Nice work :thumbsup:

Mike

[SkyViking]

What a beautiful galaxy field, and the two main actors are nicely contrasting. Good call to present them together I reckon.
I too see some faint wispy clouds in the left half of the image.

[Bassnut]

Gee, thats fair pops on opening, very well done, so sharp, detailed, contrasty and excellent colour. So many galaxys.

[Placidus]

Cheers, Russ! Took a couple test shots as my NGC catalogue had a seriously wrong size for 5078. Never trust anything!



Wow, thanks, Andy. Will do as commanded. All we need is for that bad ole yellow moon to go away at the same time as the clouds.



Thanks, Tim.



Thanks, Mike. Regarding the nebulosity, we had a close look at Martin Pugh's APOD. Needed to mirror-image and rotate, to match the images, but then you can see it answers pretty nearly. Trish points out that in ours, the right hand edge seems quite sharply defined.



Thank you Rolf. Nice to hear from you. I'm never quite sure what Galactic Cirrus is, but it's a candidate.

Best,
Mike

[Ryderscope]

That is a particularly stunning field.
Wonderful image MnT.

[Placidus]

Thanks Rodney, delighted you like it too. It's one we'll come back to over other new moons. Perhaps do a micro-mosaic to get a bit more of a border around the big ones.

[gregbradley]

Very nice Mike. Great framing to get both in.

Greg.

[multiweb]

+1 Love the framing and how radically different the galaxies are in structure. And superb colors to boot. Well done. :thumbsup:
PS: they look like two arnotts cream cookies (http://www.arnotts.com.au/wp-content/uploads/2015/03/Assorted_Creams_275x210.jpg).

[Placidus]

Thanks, Marc. It was fun to do, rewarding. And you are right about the dust lane on the Monte Carlo biscuits.

Best,
Mike

[Rex]

Holy cow! That is an awesome image M&T. So many galaxies, and very nicely processed. Something to aspire to.

[Placidus]

Thanks muchly, Rex. Far from the Milky Way seems to be where to find them. Around Grus is another good spot.

Best,
Mike

[andyc]

That's another peach there :thumbsup: Lovely and clean and deeeeep

[Placidus]

Thanks Andy.

Attempting to add another 3hrs of Lum late tonight after the moon's gone down, but right now the seeing is in Three Blind Mice territory so probably nothing will come of it.

[marc4darkskies]

A striking image M&T! Quite a lovely and interesting field! Reminds me I need to finish my version one day (started in 2014 :shrug:).

Cheers, Marcus

[Placidus]

Thanks for the encouragement, Marcus.

We got another 3 hours of Lum last night. Seeing was astonishingly good while the moon was up - 1.5 sec arc (and we got 4 good hours on Gum 41) but by the time the moon was down (unattended), the secondary must have started to fog up. FWHM and background brightness both rocketed.

[alpal]

Hi Mike & Trish,
fabulous results - I spent ages voyaging around looking at all the galaxies.
You've got such a perfect flat field over a large off-axis distance.
This where the 20" Planewave excels to give these deep galaxy images.

cheers
Allan

[deeplook]

Very, very nice Mike & Trish! Much detail and rich colors, beautiful to look at!

Markus

[Placidus]

Thanks, Allan! We're delighted you like it.

With typical 1.5 to 2.5 sec arc seeing the 20" at Euchareena (somewhere you can raise chooks and cows and veggies) is not necessarily sharper than a good 6 inch. But it can gather a lot of light, so our strength seems to be going after faint stuff.



Thanks Markus. Nice to hear from you.

[Ross G]

Wow!...what a beautiful galaxy photo.

Amazing work Mike & Trish.

Ross.

[Placidus]

Thanks, Ross,

Most kind. Sorry we've missed the last couple Epping meetings. Hope to see you soon.

Best,
M & T

[Regulus]

Wow, this is a poster pic. Strong satisfying colours and a velvet background with great detail in the subjects.
A really satisfying image to look at.
Nicely done.

Trevor

[Placidus]

Thanks, Trevor.

Amazingly, today's APOD was of this very area. Theirs is unquestionably sharper, but we're kind of chuffed to see that when you look at the faintest structures, ours is deeper! :D

[Geoff45]

Beutiful detail M&T. Perhaps a bit to orange in the stars. This is on my to-do list. As MS says, "so many objects, so little time"
Geoff

[Placidus]

Thanks, Geoff. Your comment led to an interesting observation. I registered our shot with the APOD shot from a couple days ago and blinked between them.

In some outer parts of the image, the saturation and colours of the stars were broadly similar to ours. For the main part however, their stars look strongly desaturated, but the galaxies right next to them are extremely saturated. Hard to explain.

[Slawomir]

Not sure how I missed this wonderful image...this photo is simply stunning:thumbsup:

I reckon it definitely deserves a quality print on metal; it would look great on a wall at night when illuminated with some nicely matched light :)

[Placidus]

Thanks so much, Suavi, our tails are wagging!