AAQ Visual Observing Section

Selected Deep Sky Objects In Crux

I thought we would finish our tour of this southern area of the night sky with a look at the most compact constellation of all – Crux, and its immediate neighbour Musca.

Alpha Crucis (12h 26.6 min RA -63° 06’ Dec) This looks like a brilliant white double which is easily seen with 40x. However don’t be mistaken as I was, the actual double is much closer at 4.1” which needed 120x to clearly split the two bright components of similar magnitude.

NGC 4349 (12h 24.5 min RA -61° 54 Dec) A fine delicate open cluster which is surrounded by a
rich star field.

Beta Crucis (12h 47.7 min RA -59° 41 Dec) Look for the contrast between a fainter strong red star close by this bright white star. This makes a stunning sight set as they are in a fine background star field.

Mu Crucis (12h 54.6 min RA -57° 11 Dec) Another fine background field surrounds this brilliant
white pair of similar magnitude. They are very easily split with 40x.

NGC 4755 (12h 53.6 min RA -60° 20 Dec) An orange star near the middle highlights this V shaped open cluster. Contrasting it with the other blue, green and yellow coloured stars you can understand why it is more commonly known as the Jewel Box.

NGC 4439 (12h 28.4 min RA -60° 06 Dec) I found this to be a small and inconspicuous open cluster. With 40x I could see a small loop of 10-12 stars with two brighter stars at one end. In the same field of view is H5, a slightly larger irregular grouping. Look for the brighter strong red star just east of this cluster.

NGC 4103 (12h 06.7 min RA -61° 15 Dec) This is a brilliant star field, with it hard to tell where the background field ends and the open cluster begins. Look for at least three bright orange/red stars in the same field of view. With 40x I could make out an elongated Z shape to the major grouping of stars.

RU 98 (11h 58.0 min RA -64° 29 Dec) This unremarkable open grouping of approx. 12 stars is easy to find by following a loop of stars west from Alpha Crucis. More interesting is the nebula IC 2966 which you may be able to see in the same field of view. Despite being listed as a bright nebula, it was anything but bright for me! Look for a small dark circular area devoid of any stars. You may need to be away from city lights to glimpse this interesting object.

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