Tuesday, December 14, 2010

Winter's starry delights..

The winter nights are often long and cold..ideal conditions for a bit of astro-imaging! The cold conditions often lead to better seeing when the skies are clear and also make long-exposure digital images less 'noisy'.  It seems that November and December this year have been particularly cold and we have enjoyed a good number of clear nights.I just thought I would post some of the images from the last couple of months..

The Andromeda Galaxy.
  This is the most distant object visible to the human eye...a staggering 2.1 million light years away!If you know where to look in the night sky, it appears as a faint fuzzy object.It is a member of our 'local' group of galaxies and shares a similar size and shape to our own Milky Way...a spiral galaxy which we see slightly inclined.There are also two other smaller galaxies in the shot..the other fuzzies! You can clearly see the dark lanes of interstellar dust and if you zoom in a bit you can see some red emission nebulae there as well.
 This shot was just over two hours of exposures.

The Outer Limits Galaxy.
  This is another spiral galaxy but this time seen edge-on.It is similar in size to our own galaxy (110,000 light years in diameter) but about 30 million light years away. There are a good number of other galaxies in the background..most noteably the ring galaxy just below the right hand star in the upper RHS of the image...one galaxy has collided with another and created a huge hole where the core of the galaxy used to be!

The Cone Nebula.
 This is just a small section of a vast star-forming region 2,600 light years away (ie within our own galaxy) in the constellation Monoceros.The red colour comes from the clouds of hydrogen gas becoming ionised by the uv light of bright young stars and the blue area is the same light being reflected by dust clouds.The nebula gets it's name from the cone-shaped column of interstellar dust.
This is the longest shot I've done so far , just under seven hours of exposures in 5min subs.

The Triangulum Galaxy.
  Another of our 'local' group of galaxies at a mere 2.3 million light years distance...seen nearly face on so that we can see the separation of some spiral arms.It is only a third of the size of the Andromeda galaxy .Again,dust lanes are apparent and also some red emission nebulae.
 Nearly six hours of exposures went into this one,again in 5min subs.

The Rosette Nebula.
  This is one of the largest nebulae (clouds) in our galaxy, measuring 115 light-years across but at a distance of 4,900 light-years.The bright cluster of young stars at it's centre are visible to the naked eye,but not the surrounding clouds of red hydrogen gas.Some impressive columns  of interstellar dust are sillhoueted against the brighter blue reflected light of the stars.

The Great Orion Nebula.
Probably the best known of our nebulae.This wonderful star-forming region hangs in Orion's sword and is vivible to the naked eye (on a clear night!) The very bright young stars at it's heart are collectively known as the Trapezium and it is their light which both illuminates and blows out the clouds of interstellar dust.The formation on the left is known as the Running Man nebula..(turn the image on its side!) and again the blue colour is reflected starlight..

1 comment:

  1. Fantastic; quite mind blowing the extent and variety of the world our God has created. Mum xx