Jewel box cluster

I think you've seen this photo before, but I'm hoping to talk more about clusters you can see from suburban back yards. I also want to talk about what you'll see with telescopes of less than $500.

This is NGC 4755, the Jewel Box. It's probably the most well-known and popular star cluster in the Southern Hemisphere. Why? There are several reasons.

The cluster is easy to find - it's just outside the very recognisable Southern Cross.

It's also very pretty, with a range of coloured stars in it. There are white stars, a number of red-yellow stars, one really red one, and some blue ones.

It's just made up of stars, which sounds obvious, but this means you don't need to find anything really dim. In turn that means it's good for inner-city viewing where the background is grey or brown rather than black.

One catch, it's not very big. If you've got a telescope with a focal length of less than about 700mm, you will need a 10mm eyepiece to get a nice view.

To see it, find the Southern Cross. At this time of year (June), it's very high in the South at in the evening (say, about 9pm). If you're in the city, you should be able to find it by looking for four stars in a kite shape, with a fifth star slightly inside the kite on the lower right. Here's a hint, look at the Australian flag! If you're out of the city it can be harder to find due to the thousands more stars you can see getting in the way. Try squinting so you only see the bright ones.

Second, zoom in on Mimosa. This is the star on the left of the cross. Have a look at Gacrux, the top star in the kite, and draw a line from Gacrux through Mimosa, and keep going about another fifth of the way along the line. Your finderscope will be very useful. (See my other blog on how to use a finderscope.)

Have a look using your lowest power eyepiece - probably a 25mm. You should see it in there somewhere.

Take your time to admire it before switching to a higher power eyepiece (probably a 10mm).