Photo of the Week for July 4, 2014
The planetary nebula M27 (popularly known as the Dumbbell Nebula) looks like a small, suspended puff of smoke when viewed in backyard telescopes on summer nights. The name, “planetary nebula,” was coined in 1785 by astronomer William Herschel, who noted the vague resemblance such objects have to the outer planet Uranus, which Herschel had discovered only four years earlier.
In this 20.7-hour composite CCD exposure taken over many nights from 2011 to this year, astrophotographer Ron Brecher of Guelph, Ontario, captured the delicate structure of the expanding cloud of gas emerging from the nebula’s dying central star. You can see more of Brecher’s astronomical images at his web site: astrodoc.ca.