Orpington Astronomical Society

Astronomy => Astrophotography => Topic started by: The Thing on Sep 21, 2012, 20:00:16

Title: NGC6280 (Open Cluster) taken at Rothe Valley 15 Sept 2012
Post by: The Thing on Sep 21, 2012, 20:00:16
Not sure if this is actually what it should be according to CdC as I can't make out the open cluster against the rest of the stars. I imaged the area anyway as I liked the dark nebula and the zillions of stars.

Aha! It's a galaxy according to Deep Sky Object Browser (http://dso-browser.com/dso/info/NGC/6280). It's the tiny orangey blob near the left edge half way up. Must be more careful selecting things in CdC!

HEQ5 Pro (recently re-greased), EQMOD, CdC, LX90 8" UHTC Baader Alan Gee II Telecompressor, Canon 350Da, NO Astronomik CLS-CCD clip filter, Lakeside ASCOM Focuser, Meade 8x50 FinderGuidescope & QHY5, PHD Guiding, APT Astro Photography Tool.

Processed in IRIS. 10 flats, 8 darks, 10 offset/bias frames. 20 x 300s (1h40m) at iso800. Stacked with sigma 1.5 with 1 iterations. Colour and dynamic stretching, wavelet sharpening and binning twicex2 (which means Mark the big version was binned x2, the small version was binned again x2 to make it smaller).

Larger Version
(http://ancientlight.amateur-astronomy.org//images/NGC6280_Rother_Valley_20x300s_sm.jpg) (http://ancientlight.amateur-astronomy.org//images/NGC6280_Rother_Valley_20x300s.jpg)
Title: Re: NGC6280 (Open Cluster) taken at Rothe Valley 15 Sept 2012
Post by: MarkS on Sep 21, 2012, 23:19:58

Actually I quite like this.  Apart from the galaxy there's a nice variation in star colours and there are definite patches of dust.

To the best of my knowledge, this is not a area of sky that's frequently imaged!

Mark
Title: Re: NGC6280 (Open Cluster) taken at Rothe Valley 15 Sept 2012
Post by: Carole on Sep 21, 2012, 23:46:02
I like it too, love the star colours and dark nebula. 
Your optics seem to have recovered Duncan, or is this a different telescope?

Carole
Title: Re: NGC6280 (Open Cluster) taken at Rothe Valley 15 Sept 2012
Post by: The Thing on Sep 22, 2012, 13:59:21
Quote from: Carole on Sep 21, 2012, 23:46:02
I like it too, love the star colours and dark nebula. 
Your optics seem to have recovered Duncan, or is this a different telescope?

Carole

Thanks Carole. Same scope etc. Just have tweaked the mount for smoother guiding (lots of grease everywhere), cleaned the optics and drank a lot.
Title: Re: *NGC6813* (Open Cluster) taken at Rother Valley 15 Sept 2012
Post by: The Thing on Sep 22, 2012, 14:04:34
I have solved the image in Astrometry.net. It's between Vulpecula and Albireo (which was where the scope was pointed). Center (RA, Dec):   (295.548, 27.313)

(http://nova.astrometry.net/annotated_display/34144) (http://nova.astrometry.net/sky_plot/zoom1/19676)
Title: Re: NGC6280 (Open Cluster) taken at Rothe Valley 15 Sept 2012
Post by: Fay on Sep 22, 2012, 16:25:41
That really is very nice Duncan, great colour & lovely stars
Title: *NGC6813* (Open Cluster) taken at Rother Valley 15 Sept 2012
Post by: The Thing on Sep 22, 2012, 17:25:39
Thanks Fay.
Title: Re: NGC6280 (Open Cluster) taken at Rothe Valley 15 Sept 2012
Post by: JohnP on Sep 22, 2012, 18:48:10
Yep agree with all comments Dunc. Your images have come on leaps and bounds since you 'stripped your mount...'.   Oh err Miss's

Very nice wide field.

John.
Title: Re: NGC6280 (Open Cluster) taken at Rothe Valley 15 Sept 2012
Post by: JohnP on Sep 22, 2012, 18:56:23
Yep agree with all comments Dunc. Your images have come on leaps and bounds since you 'stripped your mount...'.   Oh err Miss's

Very nice wide field.

John.
Title: Re: NGC6280 (Open Cluster) taken at Rothe Valley 15 Sept 2012
Post by: mickw on Sep 22, 2012, 19:33:59
This is very nice Dunc

I may be wrong (nothing new there) but you seem to be processing a lot more/better.

Is it your switch to Iris ?

Everything seems much more detailed with cracking colours
Title: Re: NGC6280 (Open Cluster) taken at Rothe Valley 15 Sept 2012
Post by: The Thing on Sep 22, 2012, 19:36:18
Its IRIS. Follow Marks crib sheet and instructions for gradient removal  and you can't go too far wrong.
Title: Re: NGC6280 (Open Cluster) taken at Rothe Valley 15 Sept 2012
Post by: Jim on Sep 22, 2012, 19:42:07
Really nice Duncan. Be nice to do a star count; anyone know how to do that?
Title: Re: NGC6280 (Open Cluster) taken at Rothe Valley 15 Sept 2012
Post by: MarkS on Sep 23, 2012, 12:54:30
Quote from: Jim
Be nice to do a star count; anyone know how to do that?

IRIS!
On Duncan's jpg I ran:
setfindstar 1   (this recognises a star as being anything brighter than 1 std dev above the background.
followed by
findstar

It found 7,100 stars but I reckon it had still found less than half so there's at least 14,000

Duncan, if you run the commands on the original you might get a better result.
Title: Re: NGC6280 (Open Cluster) taken at Rothe Valley 15 Sept 2012
Post by: The Thing on Sep 23, 2012, 13:14:20
I'll give it a go!
Title: Re: NGC6280 (Open Cluster) taken at Rothe Valley 15 Sept 2012
Post by: The Thing on Sep 23, 2012, 14:14:02
On the original PIC file IRIS says "Warning, too many stars"  and returns:
7572 at 1 sd
8510 at 1.5 sd
8744 at 1.75 sd
8510 at 2 sd(?)

I suspect that the dimmer stars are too close to the background level to be detected .
Title: Re: NGC6280 (Open Cluster) taken at Rothe Valley 15 Sept 2012
Post by: RobertM on Sep 23, 2012, 19:07:52
That's a really excellent result Duncan, you must be well pleased with that.  These SW mounts seem to respond well to a bit of TLC don't they !

Robert
Title: Re: NGC6280 (Open Cluster) taken at Rothe Valley 15 Sept 2012
Post by: Jim on Sep 24, 2012, 10:18:11
I think there may be some sort of overflow problem in IRIS with the message TOO MANY STARS. I tried Roberts IC1848 and it also came out with about 7000 stars. I found DSS has a star count function and counts 5096 for Duncans NGC6280 and 12277 for Roberts IC1848. Seems more accurate?