Thank you for joining the Earth & Sky Mt John Star Watching tour, here are tonights star photos taken by Fraser Gunn, all the staff at
Earth & Sky, hope that you enjoyed the experience. Feel free to copy the photos to your computer and share them around.
Here we see Crux, the Southern Cross, displayed against Milky Way background. The thousands of stars visible in this shot are only a fraction of the 300 billion or so stars present in our Milky Way galaxy. A thin layer of high cloud softens the image, and makes the colours more obvious. Gamma Crucis, (the top of the cross) is a red giant star about 88 lightyears away from us. The other three main stars (Alpha, Beta, and Delta Crucis, clockwise from bottom-left) are all much further away: at least 300 lightyears each. These are very bright, class B stars, and have a distinct blue colour due to their extremely high surface temperatures (around 30,000°C!).
Just to the left of the Cross is a darker patch of sky known as the coal-sack nebula. This is a "dark nebula," a vast cloud of interstellar dust and gas, about 60 lightyears across, and 600 lightyears away from us. The vast amounts of dust in this region block light from background stars, making it look like a black patch on the Milky Way. Dark nebulae like this can be seen splashed across the Milky Way, and their secrets can only be penetrated using instruments such as infrared or radio telescopes. Sometimes they hide baby stars in the process of forming!
In Maōri mythology, the Cross was seen as an anchor of the waka (canoe) represented by the Milky Way, whilst for the Australian Aborigines the Coalsack nebula was seen as the head of an Emu, with other dark nebulae making up the neck and body.
Southern Cross 85mm f/4 ISO 800 360 seconds
Milky Way and Southern Cross 16mm f/2.8 ISO 800 60 Seconds
Eta Carina 50mm f/4 ISO 800 60 seconds
Large Magellanic Cloud 50mm f/4 ISO 1600 95 seconds
