The Night Sky 29 January to 4 February

The night sky this week is going to be dominated by the show that the Moon is going to put on for us. In New Zealand, we’ll have to stay up until after 1am to the see the eclipse, so fingers crossed the weather plays nicely and we actually get to see it rather than some cloud. Of course while you’re outside with your telescope waiting for the Moon to slip behind the Earth’s shadow there’s a bunch of other things you can look at. This week we’ve put together a list of clusters, globular clusters and a couple of double stars that are well worth looking at. These objects are not normally the most popular, but they are spectacular in their own right. The planets are getting in better positions and you can probably get some nice views of Jupiter and Mars after the Moon show.

The Planets

Jupiter rises about 1am and earlier towards the end of the week and gets up to about 40 degrees above the horizon just before 5am which should give some fantastic views, if the conditions are favourable. Mars is a bit lower and rises about half an hour after Jupiter and the visual gap between the two planets getting bigger as the week goes past. Saturn gets a bit better to have a look at, though still very low on the horizon and rises about 3:40am and gets to about 20 degrees, just before dawn.

The Moon Show

The highlight of the week will be the show that the Moon is going to put on during the week, starting nearly at midnight on Wednesday 31 January and continuing into the early hours of 1 February. The Eclipse happens in three stages. The first is when the Moon passes into the Earths penumbra, which is a partial shadow where some of the light from the Sun is blocked. The next bit is when the Moon starts entering the proper shadow of the Earth and slowly takes on the distinctive reddish hue (see the featured image above from Wikipedia). Then the Moon reaches totality where it is sitting fully within the Earth’s shadow. The show begins at 11:50pm with the start of the penumbral eclipse. Just before 1am the Moon will start to slip into the Earth’s proper shadow, or umbra, and reach totality about hour later, just before 2am. The Moon will start slipping out of the Earth’s shadow at just after 3am and be totally free of the Earth’s umbra just before 4:15am, though still in the penumbra until about 5:10am. This event is also combined with the Moon being a bit closer to the Earth as well when the Moon reaches the perigee in it’s elliptical orbit of the Earth. The term for this is perigee syzygy and the Moon will appear about 14% larger than when it’s at its apogee. The below diagram from Wikipedia shows the different areas of shadow.

Other stuff to look at

Just because the Moon is creating quite a show this week, doesn’t mean it’s not worth having a look at some other things such as clusters, that shouldn’t be too affected by the Moon. There’s some rough maps showing the location of where the objects are, so you get the idea where to look.

NGC2477 in Puppis. This a great cluster in Puppis. It’s not super bright but will still be quite good in a moderate telescope. It’s got a few hundred stars so sort of looks like a diffuse globular cluster.

NGC2516 in Carina (the Southern Beehive). This cluster is a real beauty and is visible with the naked eye, though best through either binoculars or a telescope. The cluster is quite big, about 30 arcminutes across and contains about 100 stars.

IC2391 Omicron Velorum Cluster. This cluster is a little bit like the Pleiades but not so compact. There’s about 60 stars all up in the cluster.

NGC6025 open cluster is a great object for binoculars as it has a bright and tight cluster. Overall there are around 100 stars of which about 30 are visible easily.

NGC1851 globular cluster. This globular cluster is not that bright so will just be a fuzzy blob in binoculars but with a reasonable sized telescope you should be able to easily see the bright core and resolve many of the outer stars. The core is very bright so its quite tricky to resolve the stars towards the centre.

NGC5286 globular cluster. This globular cluster is nice and bright and visible to the naked eye under very good conditions. In binoculars, it’s a bit like a mini 47 Tucanae, except that there’s quite a bright star next to it.

M79 globular cluster is a bit of an unusual globular cluster as it’s in a part of the sky where globular clusters don’t normally appear. It looks great in a telescope of moderate power. The core is quite dense but the stars are resolvable if conditions are right. Through binoculars it looks like a big fuzzy ball though the outer stars are resolvable in the right conditions.

Vathorz Prior – Upsillon Carinae, double star. This is a very nice double star system in Carina. Both stars look quite similar and shouldn’t be too hard to split at 5 arcseconds.

Acrux – double star, This is a nice double and easy to find in the Southern Cross. The stars shouldn’t present too much of a problem to split given they’re about 4 arcseconds apart.

That’s the sky for this week. Enjoy the lunar eclipse and hopefully you will have clear skies.