PDA

View Full Version here: : Terzan 6+1 in Scorpius star cloud


John Hothersall
27-11-2014, 07:54 PM
SPX350 F4.5, ST10XME, Astrodon filters.

A quick couple of faint globular images deep in Scopius near M6. IR742nm filter allows a deeper view giving many more fainter stars by adding IR to Red and using IR as Luminance. Terzan 6 was involved with hydrogen background so I added a quick hour of Ha blended with IR+Red as Luminance.

A comparison of Red vs IR742 filters is interesting to look at, sometimes when seeing is good IR filter will give very tiny stars compared with Red some stars only visible in IR.

Terzan 6 mag 13.8, is just below centre right in first image and is quite small and is 4,200 light years from the galactic core.
Terzan1 mag 15.9.

Terzan1-IRRGB-5x5mins each
Terzan6-IRRGB-5x5min each with 6x10min Ha.


Thanks, John.

blink138
27-11-2014, 11:27 PM
amazing pictures john........... i cannot say i understand them exactly, but the pictures you do post occasionally i really like, your planet ones especially
pat

multiweb
28-11-2014, 09:26 AM
That's very cool John. :thumbsup: What ratio did you use for the blend?

John Hothersall
28-11-2014, 01:35 PM
Thanks Pat and Marc.

These are Terzan faint Globular clusters (discovered in late 1960's) lost in the sag/sco star cloud dust and brightness. The IR filter helps to make them stand out but is liable if used in place of the red filter in the RGB to create stars that are too red. If you blend IR with the Red filter at 50% and use IR as Luminance you get a better effect but still some stars are only visible in the IR - if you look at the comparison - this still gives the faint stars a red colour in the RGB mapping.

I have imaged nearly all 11 terzans but 3+4 which I may grab next year.

John.

rustigsmed
28-11-2014, 02:10 PM
that is very interesting john, congrats on the result!

Ross G
03-12-2014, 09:32 AM
Great capture John.

Very intersting work.

Good to see something different.

Ross.

SkyViking
03-12-2014, 02:05 PM
Great to see some Terzan clusters, nice work John! These are fascinating objects which are not easy to get good images of. Your IR approach sounds good, I haven't tried the Terzans with IR filter before, only Optical, but will now add this to my ever-growing todo list :)