By Paul Rodgers
One of the Milky Way’s closest neighbours just became a bit clearer thanks to an infrared image taken by the European Southern Observatory.
The Messier 83 galaxy, seen in infrared for the first time, reveals its hidden structure and hordes of previously obscured stars.
Messier 83, also known as the Southern Pinwheel Galaxy, just 15 million light years away in the Hydra (Sea Serpent) constellation, is 40,000 light years wide, about 40 per cent the size of our home galaxy.
But despite it’s closeness, much of its internal structure and many of its stars were obscured by clouds of dust.
But most dust becomes transparent at infrared frequencies, allowing astronomers to get a better look at it with the Hawk-I (High-Acuity Wide-field K-band Imager) instrument at the Very Large Telescope (VLT) in the Paranal Observatory in Chile. The Paranal Observatory is run by the ESO, which includes the UK. Brightly lit gas surrounding hot young stars in the galaxy’s spiral arms also fades in infrared pictures.
This clear view is important for astronomers looking for clusters of young stars, especially those hidden in dusty regions of the galaxy, one of the main objectives of the latest observation.
Messier 83 is one of the brightest, if blurrier, galaxies, and can be seen using binoculars. It is famous for sharing the record for having the most supernovae – six stars exploded there in the past century.
It was discovered from the Cape of Good Hope in South Africa by Pierre Mechain discovered in 1752 but was named after Charles Messier who added it to his catalogue of nebulous objects in 1781.
The VLT’s huge mirror, its large field of view and sensitivity combined with the good observing conditions at ESO’s Paranal Observatory makes Hawk-I, which began operation in 2007, one of the most powerful, and sought after, near-infrared imagers in the world.
Great article , Paul. I have seen M83 from my rooftop with a Mead telescope and the little oblate blur was worth the 2 hours of searching! Good to know we have a few better pictures of it now!