The night sky this week is without the Moon, which is fantastic for having a look at deep sky objects that are normally washed out. This is great timing too because the beautiful nebulae that grace the sky around Scorpius to Sagittarius are going to be very nice viewing and astroimaging objects. The planets also remain in excellent positions this week with Venus, Jupiter, Mars and Saturn all great for viewing. So this week we are going to focus on some great deep sky objects that anyone can look at, though first we’ll do a round up of the planets.
In the evening if you go outside just after the Sun has gone down it won’t be long before Venus is visible. Because it’s winter the Sun is in the Northern half of the sky so it sets near to the North West and this is the direction you’ll find Venus as it pretty much follows the Sun and sets a couple of hours later. It’s very bright so you’ll know if you spot it, it’s magnitude is -4 so it’s considerably brighter than Sirius (-1.4, the brightest star in the sky (except the Sun)). Venus is sitting between the constellations of Cancer and Gemini and is slowly tracking towards the centre of Cancer. Which is fantastic because on 20 June it will be resident right in the middle of the Beehive Cluster, so that’s one to watch. To the left of Venus and a bit higher – nearly 20 degrees away is the 0.4 magnitude star Procyon.
Once Venus gets a bit too low to look at then swing your head around to the East and then look up at about 30 degrees and the brightest star you’ll see is not a star but the planet Jupiter. Jupiter is still in a fantastic position this week and well worth a look. Early on Tuesday morning Ganymede grazes the planet from about 2am and then on Tuesday evening Io crosses the planet from 11:40pm until about 2am and then again on Thursday evening from just after 6pm. Jupiter is in Libra and if you look to the right of the planet about 25 degrees you’ll see a reddish star. This is not Mars but its rival, as the name Antares means in deed the rival of Mars, rferring to the red colour of the star that has the same hue as the planet. Antares is in the middle of the constellation Scorpius. This star is massive, nearly 500 times the diameter of our Sun, if it was in our Solar System it’s edge would reach beyond the orbit of Mars! When it’s life has finished this star will go supernova and put on quite a show for us being only 550 light years away.
Still looking East and from about 8:30pm you should see Saturn come into view, it’s not as bright as Jupiter but still very bright at 0.4 magnitude. It is sitting very close to the galactic centre in Sagittarius and well worth training your telescopes on. On the other side of Sagittarius is the dwarf planet Pluto. This is much harder to see at a magnitude of 14.2, so you’ll need a powerful telescope. Much easier to see and getting much closer to us is Mars, as it approaches opposition in about 8 weeks. This week it is just under 80 million kms from Earth and around 18 arcsecconds in size. That is about 6 million kms closer than last week and 1.5 of arcseconds bigger.
The focus this week is on the really beautiful nebulae around Scorpius and Sagittarius. Right by the Scorpius’ sting is the Cat’s Paw Nebula or NGC 6334. It’s not really a visual target as the nebulosity is best brought out in images but you can still see some of the bright stars and with a powerful telescope you might catch some of the emission nebula in the paws. Just underneath this nebula is another large one, NGC 6357. Again, not much visible to the visual astronomy but an amazing array of colours and shapes in images. Continuing down the Milky Way towards Sagittarius is the beautiful M7 cluster, also known as Ptolemy’s Cluster. This is a fantastic visual target set against the rich Milky Way star fields. You can see this one with the naked eye and through a telescope you’ll spot a heap of individual stars.
The next stop is in Sagittarius where the Lagoon Nebula sits, also known as M8 in the Messier Catalog. This is a stunning nebula and well worth a look. In a telescope you can easily see the bright star cluster and some of the brighter parts of the nebula, even in binoculars you should see some hints of nebulosity from a dark sky location. It’s a really beautiful object to photograph. Very close to M8 is M20, also known as the Trifid Nebula. This is another fantastic imaging target and has nearly everything going on with emission, reflection and dark nebula and an open cluster. This looks great in a telescope and even binoculars as the nebula is easily seen and the bright cluster looks excellent too. Then further down the Milky Way to a point next to Saturn is the Swan Nebula or M17. This is a very bright nebula and can be seen by the naked eye in a very dark location, though best viewed with either binoculars or, even better in a telescope. In a telescope this nebula is amazing and is right up there with Orion and Eta Carina.
About two degrees from the Swan is the famous Eagle Nebula, or M16, and of course, memorialised by the famous Pillars of Creation mage from the Hubble Space Telescope (HST). Unfortunately don’t expect that view in your binoculars, but you will see the very nice star cluster and maybe a hint of nebula. In a telescope the views are much more impressive with plenty of nebula visible and even some of the dark globules can be spotted.
So good luck with the weather this week and I hope you get a change to get outside and view some of these really nice nebula while the Moon is taking a break.