This impressive view of the Whirlpool Galaxy (Messier 51) was taken by the 1.23-m telescope of the Calar Alto Observatory, in southern Spain. This famous galaxy in the constellation of the Hunting Dogs (Canes Venatici) was observed for 35 hours through red, blue and green filters, as well as a narrow-band filter for the Balmer H-α emission line at a wavelength of 656 nm. This pink emission from the recombination of ionized hydrogen was enhanced by a factor of four in the combined image to highlight the numerous star-formation regions along the spiral arms. The widespread star formation results from the compression of gas and dust in the spiral arms, which is amplified by the interaction with the smaller galaxy (NGC 5195) to the left.
Image credit: CAHA, Descubre, DSA, OAUV. Vicent Peris (OAUV/DSA/PixInsight), Jack Harvey (SSRO/DSA), Steven Mazlin (SSRO/DSA), Carlos Sonnenstein (Valkànik/DSA) and Juan Conejero (PixInsight/DSA).
CERN Courier
Jul 20, 2010
Picture of the month
About the author
Compiled by Marc Türler, INTEGRAL Science Data Centre and Observatory of Geneva University.