A portrait of two comets each passing the Pleiades and in a similar location relative to the star cluster, but taken nearly 14 years apart. And I shot both with the same lens, a 200mm telephoto, from my backyard in Alberta. On the left is Comet Machholz (C/2004 Q2) discovered in 2004 by amateur astronomer Don Machholz, and at centre Comet 46P/Wirtanen, discovered in 1948 by professional astronomer Carl Wirtanen. Both comets became bright enough to be visible to the unaided eye. I shot Comet Machholz with a Canon Rebel 300D cropped-frame camera, and Comet Wirtanen with a Canon 6D MkII full-frame camera, so the image scale is different between the two images. So … on the far right is a version with the two images layered and auto-aligned with Photoshop, so the stars and field scale and orientation of the Machholz image match and register with the Wirtanen image. Pretty remarkable that Photoshop was able to do that on images so different in scale and orientation. Having lots of stars helped. This version shows the location of two comets with respect to the Pleiades best.
The small asterism in Vulpecula called the Coathanger, aka Brocchi’s Cluster, aka Cr399, in the northern summer sky. The field is about equal to a binocular view, as it was shot with a 135mm telephoto on the Canon 60Da. This is a stack of 4 x 80 second exposures at f/2.2 and ISO 1600, unguided on the Sky-Watcher Star Adventurer tracking mount. Two additional exposures with the Kenko Softon filter blended in to provide the fuzzy star glows. Taken from home, August 18, 2014.
The Hyades open star cluster in Taurus with the bright star Aldebaran, not a part of the cluster iteslf. The smaller and more distant cluster NGC 1647 is at left. This is a telephoto lens image taking in a field similar to binoculars, and is a stack of 5 x 2.5-minute exposures with the 135mm lens at f/2 and Canon 5D MkII camera at ISO 800, plus two other exposures taken through the Kenko Softon filter to add the star glows. Taken from Quailway Cottage on Dec 7, 2015 using the iOptron Sky-Tracker.
