My search for Terzan 10…

[Dennis]

Introduction:
Inspired by Rolf’s images of faint globulars Terzan 5 & UKS-1, along with Justin’s herculean effort of HH-32, I thought that I’d attempt to take an image of Terzan 10 as a test of equipment and technique, as Gerald had kindly loaned me his SBIG ST2000 with CFW10 for a couple of nights.

Where the bl**dy hell are you???
I used The Sky 6 Pro to acquire the field and centred the view on where it plotted Terzan 10. Bad move! If I had been using my 765x510 pixel ST7, I would have completely missed the target as it wasn’t to be found at that location – something I didn’t discover until the next day.

However, the 1600x1200 pixel vista of the ST2000 managed to record Terzan 10 towards the top of the larger frame. I later used Sky Tools 3 Pro which plotted the position of Terzan 10 accurately and when prompted, downloaded a DSS image, verifying its established position.

I really should have read the Astronomy-Mall article for Terzan 10 which writes:
"One of the biggest problems in finding this globular is the incorrect positional data in several sources including Sky Catalog 2000"

Attached files:
1. Main image:
Full frame, Down sampled to 1280x960 (showing crop region)
Field centred on RA 18h 03m 27s, -26º 03’ 50”
Image scale 0.82 arcsec/pixel
FOV approx 22” x 16” (1600x1200)

2. Croped image:
800x600 crop from main image.

3. DSS Image:
STScI(US) Second Generation DSS Red, 10”x10” FOV downloaded via SkyTools

Imaging Details:
Brisbane, Qld, Australia
20th June 2010.
Tak Mewlon 180 F12 with x0.8 Reducer at an efl of 1728mm.
ST2000 and CFW10
Luminance: 2 x 15 minutes.
RGB 1 x 10 minute each.

Terzan 10 is listed as:
Apparent magnitude: 14.9
Brightest star: 19.7
Size: 0.3 arc minutes

Excuse the LRGB processing, I have much to learn and for this image, I just head-butted the data to beat it into submission – I know not yet how to do this stuff properly!

Terzan globulars:
Some background details on the Terzan globulars can be found here.
http://natkobajic.netfirms.com/listTERZAN.html

I also found and ESO paper which identifies Terzan 10 as ESO456-SC38.
http://aas.aanda.org/index.php?optio...63/ds6163.html

A pdf article can be downloaded from the right hand Table of Contents under Abstract which shows images of Terzan 10 and UKS-1 taken with the European Southern Observatory 3.55 m New Technology Telescope (NTT) equipped with the SUSI camera and a 1024x1024 thinned Tektronix ESO CCD at the Nasmyth focus B.

Finally, this image would not have been possible without the generous sponsorship of Gerald and his ST2000! Thanks Gerald!

Cheers

Dennis

[h0ughy (David)]

Dennis you are the Indiana jones of the Australian Astro world - fair dinkum

great result from excellent research and delivery

[SkyViking (Rolf)]

Congratulations Dennis, that's a great result! It's nice to see all these obscure targets being imaged
I notice you got the deep red colour there, it looks beautiful and really gives a sense of the obscuring dust. Mine were not so red because I had to image without IR filter to catch as many photons as I could...
Yeah I remember reading the Astronomy-Mall article and noticing that several of the positions were off. I can confirm that at least Starry Night Pro 6 shows both Terzan 5 and UKS-1 in their correct positions.

[Ric]

That's a capture and a half.

Top stuff Dennis

[JD2439975 (Justin)]

Excellent capture of an obscure & very small wee beasty Dennis, well done indeed.
These things are hard enough to find sometimes even with true co-ordinates, just lucky it was still in frame.

Was just looking at it in WWT...WOW it is very small, at my native 1.2m FL it's just another star almost, lost in a wide field.

Thanks for the links to the other Terzan globulars, adds nicely to my list of future targets.

So are you thinking of hunting the complete set if conditions/time/interest allows?

[Dennis]

Thanks for looking and commenting – I appreciate your comments.

The image looks a little too “dreamy” compared to what I think it “should” look like due to a combination of on-the-job learning and the use of noise reduction tools to offset the noisy background from not enough data.

Originally Posted by h0ughy

Dennis you are the Indiana jones of the Australian Astro world - fair dinkum
great result from excellent research and delivery

Dave – I’m just following in the footsteps of Rolf and Justin; they do all the hard work in finding these esoteric faint objects!

Originally Posted by SkyViking

Yeah I remember reading the Astronomy-Mall article and noticing that several of the positions were off. I can confirm that at least Starry Night Pro 6 shows both Terzan 5 and UKS-1 in their correct positions.

Rolf – thanks for the heads up concerning the plotted position in SNP, I have SNP Pro Plus 6 although my field use Notebook only has 512Mb RAM so it really struggles with SNP.

Originally Posted by Ric

That's a capture and a half.
Top stuff Dennis

Ric – Thanks, your words give me confidence.

Originally Posted by JD2439975

So are you thinking of hunting the complete set if conditions/time/interest allows?

Justin – I probably won’t go for the whole set although if Gerald loans me the ST2000 for a while longer I’ll definitely try to image a few others!

Cheers

Dennis

[renormalised (Carl)]

Nice shot, Dennis....good effort!!!

[RobF (Rob)]

Fantastic work Dennis. Enjoyable and informative too, as always!

[Moon (James)]

Denis - thanks for posting this, I found it very interesting.
I've never visited the aanda website before - some amazing stuff there.
James

[Dennis]

Thanks Carl, Rob and James for your comments – I appreciate them.

I’ve just completed an animation between the Mewlon 180 and the DSS Plate downloaded via SkyTools 3 Pro as follows:

Frame 1: LRGB with Mewlon 180 at F9.6 with ST2000/CFW10.
Frame 2: Downloaded STScI (US) Second Generation DSS Red Plate.

WARNING: File size is approx 170Kb.

Cheers

Dennis