On Saturday 22 July 2013, I took a look around the summer night sky through the eyepieces of the Planetarium’s 12 inch Dobsonian telescope. It was a beautiful clear evening. What was there to see? Here are some images to give you an idea.
Closest and brightest (a little too bright to be honest) in the sky was the gibbous Moon, still beautiful after 4.6 billion years.
After starting with the gibbous Moon’s magnificent desolation, a mere 380 000 km away, I moved on to some deep sky objects (there were no planets in the sky).
Lyra’s famous Ring Nebula, M57, looks like a tiny delicate grey smoke ring to the eye through the eyepiece. Even imaged in a 9 second camera exposure it is still delightfully bijoux but the colours of the expanding clouds of gas which make up this planetary nebula are revealed. M57 is a classic planetary nebula, formed from shells of gas erupting from a red giant star as it declines into the white dwarf state.
In the constellation Vulpecula you can find another planetary nebula, M27, the Dumbbell Nebula. I think this image shows why it is sometimes called the ‘Apple Core Nebula’! It lies 1360 light years from Earth and at its centre possesses the largest known white dwarf star.
Globular cluster M13 is home to over 100 000 stars packed together in a ball only 150 or so light years across. In the constellation Hercules, it is located at a distance of 25 000 light years from the Sun. These bright orangish stars are ancient red giants, globular clusters are dominated by M-class stars.
Twelve million light years away in the constellation of Ursa Major is a couple of sibling galaxies. One is the popular spiral galaxy M81. The image shows its core very well with just a hint of the spiral arms. Nearby is M82, also 12 million light years distant, it and M81 are closer than the Milky Way is to the Andromeda Galaxy. M82 is sometimes called the ‘Cigar Galaxy’ from its shape (it is also a spiral galaxy but we are seeing it edge on). M82 is the classic ‘starburst’ galaxy, so-called as new stars are being formed in it at a staggering rate. I am impressed by the red glow visible near its centre, this a massive plume of glowing hydrogen gas, expelled from the galaxy by the violent birth of new stars.
This is the celebrated M51, the Whirlpool Galaxy, only about a third the size of our own our Milky Way. Again its core stands out in the image while its elegant spiral arms are just about visible. Immediately beside it you can see the companion galaxy NGC 5195, a dwarf galaxy of uncertain type. M51 is about 23 million light years away. Some observers claim in perfect conditions can see it with binoculars. They must be really good binoculars!
Looking through a telescope at the delights of deep space is a wonderful way of connecting with the Universe. I am looking forward to sharing the sky with our visitors when our monthly Open Nights return in October (date to be confirmed).
(Camera used for most images was a Canon EOS 5D Mark II set to ISO 6400 for the deep sky objects)
(Article written by Colin Johnston, Science Communicator)