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Amaranthus
07-03-2015, 06:22 PM
The Jewel Box is a small open cluster in Crux, near the bright star Beta Crucis and the Coalsack Nebula. Situated 6,400 light years from the Sun, it is only about 16 million years old.

This was a test image, to assess the DSO capability of my ZWO ASI120MM guide camera. It is uncooled, and really meant for planetary imaging and as a sensitive autoguider (the main purpose I put it to!), but I thought it might be fun to try it out. I had the gain turned up high so that I could take short images, as these were unguided. Overall it was moderately successful, though there is star bloat.

40 x 10 sec for L, R, G and B

Details and higher rez image: http://www.astrobin.com/161950/

The 2nd image is processed just using the RGB data (i.e. no luminance channel).

LightningNZ
08-03-2015, 11:42 AM
Not bad. Gives a good indication of why this is one of the best clusters in the sky visually. The views of the Jewel Box through a big refractor are something everyone should get to experience.
Cheers,
Cam

RickS
08-03-2015, 04:41 PM
That turned out quite well, Barry.

Amaranthus
08-03-2015, 04:46 PM
Thanks Rick and Cam. Here's another one with the guide camera, this time Omega Centauri, an HDR of 1 second and 10 second stacks. Details here: http://www.astrobin.com/162187/

SpaceNoob
08-03-2015, 05:36 PM
This is by far my favourite target to observe through a telescope, apart from planets.

I remember looking through my FSQ, although considered an astrograph the stars were absolutely gorgeous and "jewel" like pinpoints with very obvious colour.

A nice rendition, thank you for posting it. The stars have kept some of their colour too! :)

Regulus
08-03-2015, 07:23 PM
O Cent, Jewel Box and Eta Carina are in my top 10 DSO's, and I love seeing photos of them.
Probably not as sharp as you might have liked Barry, but a good image nevertheless. And esp. given it was an experimental one.
Well done - Trevor

Amaranthus
08-03-2015, 07:28 PM
Uncooled and unguided, yes. It was also full moon, so I was sacrificing SNR by taking lots of very short subs, accepting the read noise penalty.

Thanks Trevor, I think the slight star bloat comes from the camera and high gain - the focus was tight. Anything more than about 10 sec with a high gain on this CMOS and the stars explode like supergiants!