Kappa Crucis

[TrevorW]

Target: M4755 Kappa Crucis, Jewel Box
Camera: Canon 350d modified, Baader 2” Skyglow filter
Exposure Capture: DLSR Focus
Scope: GSO CF RC200
EFR: f/8
Mount: EQ6 Pro
Exposure Setting: Prime focus, ISO800 ICNR off Daylight WB
Exposures: 11x180s, 3/8/09 between 7:00 and 8:30pm
Seeing: waxing gibbous 95% moon
Guiding: Orion Starshoot Autoguider using PHD with ED80
Focus: DSLR Focus
Stacking: DSS 10 darks plus flats, no bias applied
Processing: CS3

Right Ascension 12 : 53.6 (h:m)
Declination -60 : 20 (deg:m)
Distance 7.6 (kly)
Visual Brightness 4.2 (mag)
Apparent Dimension 10 (arc min)


Discovered by Lacaille in 1751-52.
This cluster was one of the finest open clusters discovered by Abbe Lacaille when he was in South Africa during 1751-1752.
This cluster is one of the youngest known, with an estimated age of only 7.1 million years (Sky Catalog 2000). Its hottest star is of spectral type B0. According to Burnham, the 3 brightest stars are blue giants of mag 5.75 and spectral type B9, mag 5.94 and type B3, and mag 6.80/B2, while the fourth brightest star is a mag 7.58 M2 red supergiant. Another mag 5.7/spectral type A1 star is probably also a member, another white supergiant: This star would be the brioghtest of the cluster at about absolute magnitude -7.7 (83,000 solar luminosities).
Situated close to the cluster is a huge dark area of the sky, right within the band of the Milky Way: the Coal Sack. This is a huge dark nebula, probably the nearest at 500 to 600 light years distance, and 60 to 70 light years diameter.

[mexhunter]

Hello TrevorW:
Very pretty image.
Unattainable for my, by my latitude, although a long time ago I saw through a telescope, in a hotel in Acapulco, that is much more to the south of my residence.
Many greetings
Cesar

[renormalised]

Nice shot, Trevor. The stars are nice and tight and look like diamonds:)

Well resolved:)

[Liz]

Beautiful and sharp image. :thumbsup::thumbsup:
This is one of our favourite, and easy to find OC, for our public nights :)

[telecasterguru]

Trevor,

Great cluster, and I love the red giant in the middle. Well defined.

Frank

[Hagar]

Nice image Trevor. Stars look nice. Just keep an eye on the histogram you appear to have clipped this image severely, wheather to get the background black or just by accident you have probably lost quite a bit in the faint areas of the starfield.

Pretty image with great stars. Looks nice.

[TrevorW]

Thanks everyone

As you can see no reflection artifact in this one

Doug I used Carboni's LP removal tool which tends too clip the black, plenty of sky glow in untouched image

Cheers

[gregbradley]

Great shot of the beautiful Jewel box which is an elusive imaging target. It looks beautiful.

Your background though is biased to the red quite a bit so a bit of colour balance to the background only may help.

Greg.

[TrevorW]

Thanks Greg

suggestions welcome

[AlexN]

A beauty!! I was hoping to attack this beautiful cluster with my RC... with the refractors it just wouldnt be the same!

Looks great, job well done! My only suggestion would be to try going deeper... You could fill the frame with stars in 8~10 minute subs!

[Miaplacidus]

Ah, lovely...

[jjjnettie]

Very pretty!

[Robh]

Lovely image! One of my favourites.

For anyone interested, the brightest stars in the cluster form a capital A (inverted in the image). The brightest star is the variable star NSV 6008 at the apex of the A. Wikipedia-Jewel Box (star cluster)-incorrectly identifies the (orange) red star as kappa Crucis. It is actually the variable star DU Crucis.
Kappa Crucis is actually at the bottom of the right leg of the A.

Regards, Rob

[TrevorW]

Thanks Alex, JJJ, and Star Name

Rob for the info