Object of the Month: The Whirlpool Galaxy

The Whirlpool Galaxy or Messier 51 is one of the more spectacular astronomical objects that can be photographed by the Telescope.

Composite RBG, H-Alpha and Clear images taken with the BRT

The two galaxies initially came together about 600 million years ago and it is believed that the smaller galaxy passed forwards and backwards through the main galaxy before settling slightly behind where we see it now.

It was discovered in 1773 by Charles Messier and was the first galaxy to be recognised as a spiral galaxy. It was named the Whirlpool galaxy for its dramatic swirling shape. Older yellow stars cluster around the black hole in its centre whilst clouds of hydrogen are constantly compressed into newborn stars on its spiral arms.

A black and white image with the Clear filter taken by the BRT

Telescope Tips:

• Galaxies are faint so use an exposure time of 120000 - 180000ms (two to three minutes).
• Take an image with the BVR colour filter to see the yellow of the older stars in the centre and the blue younger stars on the arms.
• For a really spectacular image try the Clear filter for a stunning black and white image.
• For a less visually stunning but nonetheless fascinating image, take an image with the H-alpha filter to see the areas of star formation highlighted.