Ngc 5247

[markas (Mark)]

Rarely imaged, NGC 5247 lies about 60 Mly distant in Virgo. It is a grand design galaxy, and not believed to have interacted with any other.


Shot over two nights last week for only 100 minutes of L, and 3hours RGB, half of which was spoiled by heavy dew and intermittent fog.


Only half of the RGB subs were unaffected, but I used them all anyway as loss of colour detail shouldn't matter too much as long as the L is clean.....


Probably several more hours would be nice on this but that is for next year.


24' x 22' FOV; 300mm RiDK; Moravian G4;ASA DDM85 unguided


Mark

[gregbradley]

That's a pretty galaxy. Nicely done.

Greg.

[willik (Willik)]

Very nice image

[astronobob (Bob)]

Looking the good's there Mark, & resolved that dark dust clump in the galaxy center. good show !

[markas (Mark)]

Greg, Willik, and Bob,
Thanks for your comments.

Greg, have you used Arcsinh Stretch in your PI processing? I found that it added artifacts to bright star cores in the RGB master frame. I haven't really chased it down, so this rendition is using good old HT stretch only. Any advice
Mark

[gregbradley]

Originally Posted by markas

Greg, Willik, and Bob,
Thanks for your comments.

Greg, have you used Arcsinh Stretch in your PI processing? I found that it added artifacts to bright star cores in the RGB master frame. I haven't really chased it down, so this rendition is using good old HT stretch only. Any advice
Mark

I use CCDStack and Photoshop. I rarely use PI to help with a difficult registration but even then I tried doing that the other day and I couldn't get it to work. Not sure if they have changed it.

Common practice is to remove the stars first before a heavy stretch to avoid blowing out stars. Or do a star mask first so the stretch only applies to everything bar the stars.

Your stars do look a little harsh. Their brightness should be bell curved as the airy disc (the smallest point of light your setup can produce) has lighter rings around the centre.

Greg.

[strongmanmike (Michael)]

You've made the most of your conditions there Mark, a cool galaxy, has a real "rotation" feel about it

Mike

[markas (Mark)]

Thanks for your comments, Mike.
I note you also like to be with your equipment as it's imaging.
So I guess you've also experienced the sinking feeling as the humidity climbs over 90% and everything gets wet with dew.....
Mark

[strongmanmike (Michael)]

Originally Posted by markas

Thanks for your comments, Mike.
I note you also like to be with your equipment as it's imaging.
So I guess you've also experienced the sinking feeling as the humidity climbs over 90% and everything gets wet with dew.....
Mark

Indeed, I'm very fond of my gear

I've been in a dome for the last 8 years, so luckily dew has never been a problem for me since, never forms inside the dome, fog is the only moisture problem that can affect me but also luckily, this has not been a particularly huge issue at my current elevated site, north of Canberra. Before the dome though, yeah, you bet, dew was a bloody PIA I had good optics heaters, so the glass was always dry but everything else..sheesh! Packing up wet gear, then having to spread all my wet gear around the house to dry out before going to bed, was never popular...certainly not with the other half, that's for sure

Mike