Binocular Object of the Month - March 2010 - Southern Beehive NGC2516 in Carina

In March, the southern sky is a happy hunting ground for binocular viewing, especially in the area between and around the three crosses. Three crosses?
    Directly south this month around 9pm, you will see three crosses lying on their sides amongst the rich star fields of the Milky Way, like surf boards queuing up on a foaming wave. They are, from left to right (or from east to west): The Southern Cross (Crux), The Diamond Cross (a not so well know asterism), and the infamous False Cross, which is shared between the constellations Carina and Vela. They are shown on the chart below.

    You will notice the very bright star Canopus further to the west of the False Cross. Canopus is the second brightest star in the sky after Sirius and is the brightest star in the constellation Carina. You’ll also notice the Large Magellanic Cloud below Canopus and a couple of cross lengths ‘beneath’ the Diamond Cross.
    Now the area of the sky between Crux and the False Cross is alive with beautiful binocular objects, especially in the vicinity of the Diamond Cross’s ‘top’ star, theta (q) Carinae, which is the brightest star in the beautiful open cluster IC2602. IC2602 has been named ‘The Southern Pleiades’ and is a stand out object in binoculars. In the orientation shown in the chart, above and left of IC2602 is the famous ‘Eta Carinae Nebula’ (shown as h on chart) which is spectacular in binoculars.
    Take time to explore that whole section of the sky, starting from Crux and moving towards the False Cross. You’ll be gob smacked.
    But the main subject of this article lies at the ‘foot’ of the False Cross. It is the splendid open cluster NGC2516 with around 80 stars, its brightest being a magnitude 5.2 giant red star. This cluster has been dubbed ‘The Southern Beehive’, maybe quite justifiably when you compare it to M44, the Beehive, in Cancer to the north this month. (They are both visible at the same time in March. Move from north to south and compare them.)
    To find NGC2516, simply locate the False Cross in the sky, then move about 3^o ‘below’ the bottom star, e, in line with the Cross. In a reasonably dark sky, it is obvious to the naked eye as a fuzzy patch of light. Binoculars will reveal it in sparkling detail. It occupies an area similar to a full Moon, and is about 1,100 light years away.
    It has been suggested that the cluster is ‘cross shaped’. What do you think?

NGC 2516

For a detailed list of more binocular objects in the southern sky, see my book “Heavens Above – A Binocular Guide to the Southern Skies”. A link is provided at the bottom of this website’s Home page.

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