Well, on my 3rd attempt, I finally succeeded in recording the globular cluster Tonantzintla 2 in Scorpius!
Thursday night saw me collecting photons from the incorrect region of Scorpius due to using The SkyX and SAC Ton 2 as the “GoTo” coordinates, with Friday night delivering cloud cover and showers. Saturday night found me pointing at the correct region, thanks to SkyTools 3 Pro, although intermittent clouds compelled me to collect the Luminance data E of the meridian and the RGB data on the West. The location of Ton 2 in The SkyX was awry by approx. 20 arcmin.
The globular cluster Tonantzintla 2 (Pismis 26) was discovered by Paris Pismis in 1959 on Schmidt plates taken at the Tonantzintla Observatory, Mexico. The cluster is also designated GCL B1732-3831, BH 236 and ESO 333-SC16. A relatively lesser known globular, its color magnitude diagram was finally taken in 1996 by Ortolani, et al. They found a red horizontal branch in a moderately loose cluster. It’s location at 2 Kpc from the galactic center makes it is a member of the bulge population of globulars, but is only moderately metal rich. It lies 6.4 kpc from the Sun.
The first image file is the full frame 1600x1200 resampled down to 800x600.
The second image file is an 800x600 full resolution crop from the centre of the frame.
A summary from SkyTools 3 Pro:
Ton 2
Globular Cluster
R.A.: 17h36m11.0s Dec.: -38°33'12" (2000) in Scorpius
Magnitude: 12.20
Size: unknown
Apparent Data for 2011 Jul 23 GMT+10 at Brisbane, Australia:
I often wonder about the names some of these objects are given. It's particular name sounds like it's either Godzilla's sister or some Mayan/Aztec/Incan deity or ruler..."Tonantzintla from Teotihuacan"
Superb Dennis! Such an obscure target and a challenge to acquire and process no doubt with the contrasting star luminance in the FoV. Top work! Thanks for the background details on the target too, very informative.
Thank you for all your nice words of appreciation and encouragement, that particular imaging run proved to be quite an enjoyable session, where all the equipment behaved itself and most things ran smoothly – something quite rare!
I have re-processed the images as in the original set, I made the mistake of “flipping” the Red & Blue Layers prior to applying their respective Flats, thus introducing an undesirable faint violet blob where none should have been.
I hope you can notice the difference in (correct) processing!
That's a very nice image Dennis, and a beautiful contrasting field It really shows how the globular is reddened by all the dust. Interesting how it is somewhat elongated in shape, I noticed this too when I imaged Terzan 5. They are probably both being distorted by the tidal forces in the galactic centre.
I actually prefer the first version of your image, it seems more soft and shows more stars in the globular. The second version appears slightly more clipped.
Great work and dedication as usual. Thank you for sharing this.
@Rolf – thank you for your feedback on the re-processed image, your comments provided me with much food for thought.
The clipping likely arose through selecting the background to process in an attempt to remove noise and an overall muddy texture. Sometimes too much time at the monitor can make you one eyed!
