NGC3359 and the 'Little Cub'

[AKB]

Inspired by this recent post in the imaging section...

 

... I set out to look for it myself.

Here's 20 x 30 sec from my 9.25" Hyperstar / Ultrastar EEVA rig:

 

 

 

It's barred spiral galaxy about 60-70 million light-years from Earth (some variation when I was trying to look this up), in the constellation of Ursa Major.  According to Wiki, the central bar is approximately 500 million years old.  Initially, I was interested, as usual, to see what deeper fuzzies might be around, and I've labelled some of them in the image:

• 2653194 – Mag 17.7, 1382 Mly
• 2649365 – Mag 18.8, 3138 Mly
• 2653742 – Mag 19.1, 3636 Mly
• 5339316 – Mag 19.7, 3880 Mly (the faint one to the right of the brighter star)
• 3382663 – Mag 19.1, 3809 Mly

... no idea how accurate these distances really might be, given the variation I found on NGC 3359 itself.

However, reading further, there's something much, MUCH more interesting going on here: NGC 3559 is "devouring" a much smaller galaxy, nicknamed the 'Little Cub'.  So nothing terribly unusual about that, but this is a very special galaxy.  There's a really interesting report here: https://news.ucsc.edu/2017/07/little-cub-galaxy.html describing it thus:

"As the Little Cub has remained almost pristine since its formation, scientists also hope its elements will reveal more about the chemical signature of the universe just minutes after the Big Bang."

"The Little Cub was initially identified as a potentially pristine dwarf galaxy in data from the Sloan Digital Sky Survey (SDSS). Follow-up observations were conducted using the 3-meter Shane Telescope at Lick Observatory and the 10-meter Keck II telescope at the W.M. Keck Observatory."

There's an image in that report, presumably from one of those scopes – was there any chance that I could detect it ...???!

It's just outside the above FOV, but here's a negative zoomed in on the relevant area:

 

 

There's a very, very faint smudge at around 4 o'clock at the edge of this image, just to the lower right of a line of three stars, which just might, with the 'eye of faith', be a hint of it.

This was the only EEVA image I took yesterday, being otherwise occupied, but I had also set up my imaging scope (Esprit 120ED, F7, ASI294-MC) to capture about 2 and a half hours on the same target.  Very stupidly, because I had been in a rush, I forgot to turn on the cooling, so the colour image was, frankly, worse than the EEVA one, but here's a crop of that too (vastly over-stretched):

 

 

Smudge in the same place ???

So exciting.  I'm going to go and look for this more carefully on my next EEVA session, since the mono rig is clearly much better at this than the colour imaging one.

Tony

 

Edited March 7, 2022 by AKB
Distance off by 10^6 ! Thanks @tomato

[RobertI]

Very interesting result and nice piece of investigation. Certainly looks like a smudge to me! 

[Mike JW]

Hi Tony,

It is these sorts of posts/observations that really make EEVA stand out - sufficiently detailed image of a galaxy to warrant closer inspection to spot the star forming regions and any other details, wider context to pick up those seriously distant galaxies, information and links to articles and then further fascination in  this case of trying to spot the dwarf galaxy being consumed and all in 10 minutes.  (I agree there is spot of fuzz at the right place).

Excellent work, presentation, inspirational - makes me want to rush out there and point the 15 at the area.

Maybe Monday night, but it will be so high up I shall be pointing the Dob where it gets very difficult to be accurate.

Cheers,

Mike

[tomato]

Great post, if I get a chance I’ll put the widefield cameras on my rig and have a go at capturing the “Little Cub”.

May I point out a typo in the text, I presume the galaxy distance is out by a factor of 1M?

[Mike JW]

I should know better than to try for a faint object in moonlight but 'The Cub' has intrigued me.

Below is a close up of the region and yes there is some noise in the right place. I would call it 'organised noise' - it is not the normal pattern. No way I am claiming I have spotted the cub - a bit like visual observing when you have to use AV to get a hint of something (this is in category 'AV maybe or maybe not' - wishful thinking). For comparison  I have included a zoomed in shot from Alaldin with the Cub marked.

I need to return on moonless night.

 

 

 

 

 

Mike

[Mike JW]

NGC 3359

Here we again , two weeks later. Better conditions, and using 2x2 binning. Adjusted settings to remove the noise and hence the very black background to leave what I hope are true fuzz patches. Sure enough there are the two grey patches which correspond to The Cub, as per Aladin view.

Mike