NGC 3184 (Little Pinwheel Galaxy)

[alan4908]

NGC3184, also known as the Little Pinwheel Galaxy, is located in Ursa Major at the border with Leo Minor and is about 40 million light years distant.  Since it is only 20 degrees inclined from face on, its distinct spiral structure is clearly visible. The yellowish core contains old mature stars, while the spiral arms show star forming HII regions scattered amongst mainly blue stars. A dim gaseous disc surrounds the galaxy which has been found to contain over 1000 compact star clusters.

To the right of the image you can also see a red giant star. A few much more distant galaxies are also visible in the background.

This LRGB image was taken with my Esprit 150 and represents just over 12 hours integration time.

LIGHTS: L:25, R:16, G:17, B:15 x 600s, DARKS:30, BIAS:100, FLATS:40 all at -20C.

Alan

[DaveS]

Very nice indeed.

NGC 3184 is a new one on me, but looks well worth imaging

[alan4908]

23 hours ago, DaveS said:

Very nice indeed.

NGC 3184 is a new one on me, but looks well worth imaging

Thanks - yes, it is well worth the effort of imaging but take note that it has a small apparent size. I was at 0.7 arc seconds per pixel and still decided to crop it.

Alan

[DaveS]

My ODK rig runs at a native 0.61"/px though how much of that resolution is actually useable is a moot point.

[alan4908]

18 hours ago, DaveS said:

My ODK rig runs at a native 0.61"/px though how much of that resolution is actually useable is a moot point.

Yes, given the relatively good UK seeing conditions from my site I did wonder if going below 0.7 arc seconds/pixel would bring any additional resolution to my images, however, I subsequently convinced myself that I was at the limit for my system + site. 

Alan

[wimvb]

Excellent image of this little gem. I found that it benefits from adding Ha.

https://www.astrobin.com/full/th3p15/B/

[michael.h.f.wilkinson]

Really lovely, and not often seen on SGL.

 

[alan4908]

On 02/07/2021 at 08:22, wimvb said:

Excellent image of this little gem. I found that it benefits from adding Ha.

https://www.astrobin.com/full/th3p15/B/

Thanks - yes, the Ha filter definitely makes the star forming regions stand out (nice pic by the way) I will have to try this should I ever revisit this target. 

[alan4908]

On 02/07/2021 at 08:41, michael.h.f.wilkinson said:

Really lovely, and not often seen on SGL.

 

Thanks Michael. 
 

[peter shah]

That's beautiful Alan

[tomato]

Great image, plenty of sharp detail and colour.

[alan4908]

On 04/07/2021 at 15:57, peter shah said:

That's beautiful Alan

Thanks Peter 

On 04/07/2021 at 16:15, tomato said:

Great image, plenty of sharp detail and colour.

Thanks - Yes, it definitely is a colourful object, so it is a little surprising that it doesn’t often appear on SGL, perhaps  this is due to it’s small apparent size.

Alan

[tomato]

Yes, I only came across it this year when looking for small, photogenic galaxies to image. NGC 3938 is another nice target which doesn’t get imaged very often, I think it looks even more like a mini M101.

[alan4908]

On 06/07/2021 at 17:03, tomato said:

Yes, I only came across it this year when looking for small, photogenic galaxies to image. NGC 3938 is another nice target which doesn’t get imaged very often, I think it looks even more like a mini M101.

Thanks I shall explore that one. 

FYI I normally use CCDNavigator for selecting my targets, I mainly use this since it is also communicates ACP Expert, allowing a new target to be programmed with just a mouse click. 

Alan

[wimvb]

I use Aladin nowadays. It doesn’t have any scope information or anything, but I just set the fov close to that of my scope and camera. Aladin allows me to explore what will else beside the main target will be in the image and explore the best framing. A 1000 mm fl telescope is a wide field instrument for these small galaxies, and rather than crop, I try to include some extra ”eye candy”. All images from the 2020/2021 season on my astrobin page were planned this way.

https://aladin.u-strasbg.fr/AladinLite/

[alan4908]

14 hours ago, wimvb said:

I use Aladin nowadays. It doesn’t have any scope information or anything, but I just set the fov close to that of my scope and camera. Aladin allows me to explore what will else beside the main target will be in the image and explore the best framing. A 1000 mm fl telescope is a wide field instrument for these small galaxies, and rather than crop, I try to include some extra ”eye candy”. All images from the 2020/2021 season on my astrobin page were planned this way.

https://aladin.u-strasbg.fr/AladinLite/

Yes, I also use Aladin, which I find to be an excellent program but mainly to identify background objects within the field of view. 

Alan