Whale and Hockey Stick Galaxies

[RickS]

NGC 4631, the Whale Galaxy, is the edge-on barred spiral galaxy at bottom left of the full field. It is approximately 30 million light-years from Earth in the constellation Canes Venatici. Beneath NGC 4631 is its close companion the dwarf elliptical galaxy NGC 4627, also known as the Pup. NGC 4631 has a core of older, yellow stars surrounded by young blue stars. It has a dark equatorial dust lane and many emission nebulae glowing with the magenta of ionished Hydrogen. The central region of the galaxy is a starburst region where new stars are rapidly forming.

At top right of the field is the highly distorted pair of interacting galaxies NGC 4656 and NGC 4657, also known as the Hockey Stick Galaxies.

These galaxies are all members of the NGC 4631 group.

There are some faint stellar streams associated with NGC 4631. I can make them out faintly in the data but haven't been able to produce an image that shows them well yet. Still working on it...

Acquisition credit: Scott Johnson, Augusto Hernandez, John Kasianowicz, Daniele Malleo, Jose Mtanous and Rick Stevenson

Processing credit & copyright: Rick Stevenson

Scope: Ceravolo C300 @ f/4.9 = 1470mm FL
Mount: AP1100
Camera: FLI PL16803
Focuser: Atlas
Filters: Astrodon
Guiding: Lodestar II / Tak guide scope
Image scale: 1.26 arcsec/pixel (Drizzled/downsized)
Exposures: 34x1200s R, 28x1200s G, 36x1200s B, 85x600s L, 55x1800s H (74.3 hours)
Processing: PixInsight 1.8.5

High res versions are on Astrobin. Crop in full res: https://www.astrobin.com/full/339710/B/ Slightly downsized full field: https://www.astrobin.com/full/339710/0/

[RickS]

Here's my best attempt so far at the stellar streams. They are likely the remnants of a captured satellite galaxy rather than an interaction between NGC 4631 and NGC 4656.

[Placidus]

Heartache. Site, target, acquisition, and processing all perfect.

[alpal]

Hi Rick,
excellent picture and 74 hours! - wow.
There must be 100s of faint galaxies in the background too
brought out by such long integration.

cheers
Allan

[atalas]

Wow:eyepop: excellent Rick:thumbsup::thumbsup::thumbsup:

[LewisM]

Now, see my pareidolia is strong, and all I see is the USS Enterprise being flanked by a Klingon Bird of Prey.

[Andy01]

Apologies Rick, looks good but I’m only on the ‘iPhone (away camping) but +1 ^ Lewis!
Too funny dude 😂 lol

[RickS]

Thanks, M&T!



Thanks, Allan. Yes, lots of little fuzzies. I love the mix of colours and patterns. It's a shame we are limited by optics and the atmosphere. There's so much tiny but cool stuff out there!



Thanks, Louie!



Mine is weak but I can see that, Lewis :lol:



Have a great Easter break, Andy. The Klingons will be waiting when you get back :)

[strongmanmike]

To be honest I have always found this duo a bit boring actually, one of those objects that northerners seem to like imaging but they kinda look like nothing but straggly misshapen cigars :question: ...but this is a fine image none the less and nicely processed, the HII regions help lift the interest and the streams are very cool too :thumbsup:

Mike

[PKay]

Amazing.

[DaveNZ]

Well done Rick. What an effort.

The Ha really makes the image.

[RickS]

Thanks, Mike. I like the weird shapes but they're too small to be really spectacular objects. Maybe if someone moved them closer together that would make it easier to do an interesting composition :lol:



Thanks, Peter.



Thanks, Dave. The scope is automated but the processing was quite an effort! Agree about the Ha. It certainly does give it some zing.

[glend]

Rick, if you don't mind me asking, what is your arrangement with Sierra Remote Observatories? You credit them on Astrobin. Is that your equipment that they are hosting, or are you hiring time on pool equipment?

[Joshua Bunn]

Lovely rich and vibrant colours Rick.
Why is it you take longer colour subs than luminance subs??

Thanks Josh

[RickS]

Hi Glen, it's a system currently shared by six of us (the names mentioned in the acquisition credit.)

A group of us got together in 2014 and rented a pier at SRO. The equipment came from a few of the US based guys and we all kicked in money to pay for any other gear we needed, software licenses and the pier rental. The scope is automated with ACP Scheduler and we jointly choose targets and share all the data.

Each year when it's time to renew the lease we usually get one or two folks leave the group and we add new members to replace them. The equipment has changed a couple of times and is likely to change again soon.

I don't physically get to tinker with the gear but I often contribute on the debugging of issues, camera analysis and sub length planning, target selection and composition, etc.

I really enjoy the interaction between the team members. They're all great guys and between us we can usually solve any problem pretty quickly. It's also interesting to compare our various attempts at processing. A few of us are now looking at going a step further and setting up a remote scope in Chile...



Thanks, Josh. With colour filters you're blocking a lot of the photons that a luminance filter will pass, so it takes longer to collect enough to overcome read noise. 600 sec is long enough for our luminance subs to be sky limited but it's too short for the R/G/B subs, so we go longer on them.

[strongmanmike]

:scared2: :eyepop:......I just fainted....:prey2:


Grumble humph..grumble grumble..sheesh..

:thumbsup:

[alpal]

Wow - now you're talking.
I often look at CHART32 - it's one of my icons on my computer screen.
http://www.chart32.de/index.php/recent

I have spent many nights looking at their pictures -
many with sub arc second seeing.
Then again they have a multi million dollar setup -
way beyond most amateurs.

cheers
Allan

[Joshua Bunn]

Thanks for the explanation Rick!

[Atmos]

An excellent rendition Rick and it is super deep!

[RickS]

Still working on it and it may not eventuate, but we're all very keen :thumbsup:



Not sure we can do quite as big a scope but still a decent size (400mm aperture.) I love the Chart32 stuff too, Allan.



No problem, Josh.



Thanks, Colin.

[Camelopardalis]

Beautiful :thumbsup: looks like lots of stellar activity with all the red and blue regions.

[RickS]

Thanks, Dunk!

[Geoff45]

Great images Rick. Those tidal streams are always difficult.

[RickS]

Thanks, Geoff. I think we need more aperture :)

[willik]

Sperm Whales looks good great detail
Martin

[multiweb]

Very nice. Great colors. :thumbsup::thumbsup::thumbsup:

[RickS]

Thanks, Martin & Marc.

[Ryderscope]

A great composition again managing to bring forward an excellent image.

[RickS]

Thanks, Rodney!

[gregbradley]

An excellent image there Rick. I don't think I have seen that combo before.

Greg.

[RickS]

Thanks, Greg. It's a common combo for northerners but we were able to go fairly deep.

[Paul Haese]

Excellent work Rick. Love the colour, the detail and the composition. Incredible universe we live within.

[RickS]

Thanks, Paul. It is an amazing place!