The Summer Triangle and Milky Way

The summer triangle’s corners are marked by the three first-magnitude stars Deneb (in Cygnus), Vega (in Lyra) and Altair (in Aquila). The teeming stars of the milky way make it difficult to identify the constellations in this image, taken on 28 August 2019 from my home in Cheshire, England.

The DSLR camera used for the exposure (Nikon D810A) is modified to allow extended response at the red end of the spectrum, which allows it to capture the hydrogen-alpha emissions from nebulae such as the North America (NGC7000) seen clearly at upper left.

The other red nebulae include the Pelican, the Gamma Cygni nebula surrounding the star Sadr and, faintly seen to the left, the circular fragments of the Cygnus Loop or Veil Nebula, a supernova remnant that is believed to have exploded about 21,000 years ago. These are all labelled on the following image.

The dark rift running through the milky way in Cygnus is the start of a feature that extends all the way to Centaurus in the southern sky. It lies in the plane of our galaxy, obscuring the centre from view. It is thought to comprise molecular dust clouds which are opaque to visible light but can be penetrated with telescopes sensitive in the infra-red part of the spectrum.

Nikon D810A DSLR with Nikkor 18-70 zoom at 35mm focal length, f/5.6 and ISO 1600. Stack of 59 exposures of 30-seconds each, calibrated with a master dark comprising 25 frames of the same duration. Processed in PixInsight.