A string of galaxies

[wimvb]

Imaged feb 5, 2018

Image details:

• Skywatcher Explorer 150P-DS on a Skywatcher AZ-EQ6 mount, no guiding
• Camera: ZWO ASI174MM-Cool at -30 C, gain 189 (unity gain)
• Filters: ZWO LRGB, 160 x 20 s (L), 40 x 30 s (RGB, each)
• Total integration time: 113 minutes

(Click on the image to see a larger version)

NGC 2300 is located at a distance of some 87 Mly from earth, while NGC 2276 is about 5 Mly further away (depending on reference up to 120 Mly from earth).

The smaller galaxy IC 455, at the very bottom of the image, is part of the group, and is about 94 Mly away

NGC 2276 is gravitationally coupled to NGC 2300, and moves through intergalactic matter (IGM). This movement causes a bow chock which compresses the outer regions of the galaxy. In this pressurised region, several supernovae have been observed.

PixInsight found a string of 12 more galaxies in this region.

I also managed to collect about 90 frames at gain 300. Unfortunately, for some reason the fov had shifted, and the framing doesn't allow combination of the data. But this region is circumpolar, and always more than about 55 degrees above the Northern horizon, so I may be able to collect more data before astro darkness ends ...

[gonzostar]

Lovely image as always Wim. Only 113 minutes to collect this quality of data. When does your astro darkness come to a end?

Need to save and move away from DSLR!  

[gorann]

Wim, very nice. How did you do it at times like these? You must have run out in your night dress and assembled your kit in no time while freezing your bottom end off and shooting the moon down.

[wimvb]

Thanks, Dean.

Astrodarkness ends in mid/late April. But with the weather the way it is, that probably means only 2 or 3 imaging opportunities till then.

Yes, mono is the way to go.

[wimvb]

1 minute ago, gorann said:

Wim, very nice. How did you do it at times like this? You must have run out in your night dress and assembled your kit in no time while freezing your bottom end off and shooting the moon down.

No, the moon came up at around midnight, at about the same time as the clouds.

But I did almost freeze my fingers off. It must have been about -10 to -12 C.

Actually, the Clear Outside app is quite accurate in predicting clear nights, and friday may be next opportunity. An obsy would be handy, as setting up and aligning takes at least an hour. Too many cables.

[MikeODay]

Wonderful image Wim and thanks for sharing the information and the annotated image.

[wimvb]

 

Thanks, Mike. Further investigation showed that the "front" of this galaxy is very active, and has a lot of Ha regions. I may try to capture some of this, weather permitting. This target would benefit from a better resolution than my 1.6 "/pixel.

[lux eterna]

Very nice and detailed image, and with so little integration time - Respect !

Ragnar

[iansmith]

Nice image.

Cheers, Ian

[wimvb]

Last night was a clear one. It was supposed to last only till midnight, but it seems that clouds don't use the Clear Outsude app. 4 am I packed it in. I had a few misshaps, but managed to collect a fair amount if subs on both sides of the meridian. Before the meridian I collected L, and after I collected Ha and a little more RGB.

After the flip I noticed field rotation. Examining the guiding results, I found out that I had a large polar alignment error. (According to the synscan, I was pretty much spot on after two PA iterations.) Imaging so close to the ncp, this gave me a really poor frame alignment after the flip. I hope that I won't have to crop too much after stacking, and that I can use most of the new subs to combine with previous data. I just have to take darks before I can process the lot.

[Rodd]

Very nice image and great presentation.  I love the super nova remnant.  Looks like a good long focal length target!

Rodd

[wimvb]

I think the pair would fit nicely in a scope of double the fl (1500 mm) with the same sensor, and there would still be some room to spare. That would also bring the resolution to 0.8 "/pixel.

If my site were any darker, I'd go for the ifn, of which there's plenty in this region, as evidenced in Rogelio Bernal Andreos masterpiece.

http://deepskycolors.com/pics/astro/2010/11/mb_2010-11_NCP_3k.jpg

My framing is just outside Andreos image, I believe.

[Filroden]

On 08/02/2018 at 06:28, wimvb said:

Further investigation showed that the "front" of this galaxy is very active, and has a lot of Ha regions. I may try to capture some of this, weather permitting. This target would benefit from a better resolution than my 1.6 "/pixel.

You’ve done a great job at showing the front. Can’t wait to see the additional data.

[wimvb]

On 2018-02-11 at 11:10, Filroden said:

You’ve done a great job at showing the front. Can’t wait to see the additional data.

Here's a redo with additional data.

(click on the image to see a larger version)

Imaging this close to the NCP proved a bit more complicated than I had anticipated. On the second night, polar alignment was way off. This caused serious field rotation, and I had to crop a lot more than I wanted (I wanted to include IC 455). Also, the Ha that I shot (70 frames at 3 minutes each), didn't add anything. Live and learn ...

For this image I threw everything into the pot and stirred. RGB is still only 40 frames each, but L is increased to 370 frames

128 x 40 sec and 242 x 20 sec = 166 minutes (previously 53 minutes)

Total integration time for this image: 226 minutes

There's a slight increase in sharpness. Seeing was better the second night. I used a weight factor in the integration process, that was dominated by FWHM of the stars. More data (less noise) also allowed me to do a little more deconvolution.

Wednesday night is supposed to be clear again, and with the moon out of the way, I may reshoot L and add some RGB. See If I can keep the original framing.

[Allinthehead]

Looking good.

That's a pity about the framing. Same happened to me with m81 and m82. I have to do a large crop too. Live and learn.