NGC3532 - Wishing Well or Black Arrow?

[Amaranthus]

Take your pick! Also known as the 'Black Arrow', this spectacular open cluster in Carina covers an area of about 60' x 30', and sparkles with over 100 blue and yellow stars of even brightness. They look somewhat like a collection of coins shimmering at the bottom of a wishing well. This cluster is clearly apparent as a dense aggregation of stars to the naked eye, just below the Eta Carina nebula, but it is rarely imaged. It lies about 1600 light years away, and is only 200-350 million years old.

This is my first serious image with my new QHY22 monochrome camera. It is beautifully sensitive and clean, especially in the Hydrogen Alpha wavelength. Astrograph is an ED80T CF, on an AZ-EQ6 GT.

NGC3532_HaRGB_21Mar15.jpg (196.58 KiB) Viewed 7089 times

This image is composed of the following:
12 x Red at 305 sec
12 x Green at 303 sec
12 x Blue at 328 sec
7 x Ha at 1200 sec

Total integration is a little over 5 hours. There was no need for a separate luminance channel given the cluster's brightness, and the RGB channel durations are based on G2V calibration. In post-processing, the colours were perfect.

Captured in APT, calibrated in Nebulosity, stacked in DSS and post-processed in StarTools. I created a synthetic HaRGB luminance and used RGB only for the colour.

Full resolution image: http://www.astrobin.com/170102/

[admin]

Just beautiful! Such great framing.
The blend is superb with the detail of added Ha and colours from the visual spectrum.
More please!

[Amaranthus]

Thanks Ivo, I appreciate that - I put a fair bit of thought into the framing, and followed your SynthLum tutorial closely with the processing - it was really helpful. It was also a bit 'zen' like - I mucked about with the data for quite a while, then threw out my efforts and went with a fairly straightforward processing flow, and it all just... worked. StarTools just gets better, and more powerful, the more you use it.

[AndyBooth]

Wow lovely shot mate.

[Amaranthus]

Thanks Andy!

It's actually a challenging target, because the Ha emission nebula is difficult to draw out without overstretching the background Milky Way stars (too much and the background degrades into a graininess). It can look like quite a different object if one just concentrates on the cluster stars and ignores the nebula - the background gets much darker, but the traceries of gas is then lost.