Double Cluster + Astrodoc Ron Brecher + L-QEF (L-Quad Enhance Filter)
Double Cluster
Credit: Astrodoc Ron Brecher
Filters: Optolong L-QEF (L-Quad Enhance Filter)
NGC 869 (right) and NGC 884 each contain hundreds of stars and are about 13 million years old (compared to 75-150 million years for the Pleiades). Lying about 7,500 light years away and a few hundred light years apart, they have a combined mass about 6,500 times our Sun’s. However, their combined halo is more than 20,000 solar masses. The clusters are moving towards us at a speed of about 40 km/s. These open clusters are bright enough that they were originally given star designations (h- and Chi Perseus). They are visible to the naked eye, appearing as an oval foggy patch in a dark sky. They look like sparkling white diamond dust in binoculars or a small telescope. Images reveal subtle differences in the hues of the stars.
I’ve photographed the Double Cluster with just about every different scope and camera that I’ve ever used. I chose it as one of the first targets for the Sky-Watcher Esprit 120, so I could evaluate star colours and shapes. I also re-confirmed my positive views of the Optolong L-Quad Enhance Filter. I think the star colours in this image are as good as any I have seen of this object. And this image was selected by NASA as an Astronomy Picture of the Day, my first one!
NASA Astronomy Picture of the Day August 7, 2025
Tekkies:
Acquisition, focusing, and control of Sky-Watcher Wave 150i mount and other equipment with N.I.N.A. and Green Swamp Server.
Primalucelab 3″ ESATTO focuser, ARCO rotator, GIOTTO flat panel and ALTO cover motor.
Equipment control with Primalucelab EAGLE 6 Pro computer. All pre-processing and processing in PixInsight. Acquired from my SkyShed in Guelph.
Acquired under above average transparency and seeing and no Moon from July 28 – August 2, 2025.
Second Image with Sky-Watcher Esprit 120 refractor. QHY168C camera with Optolong L-Quad Enhance filter.
84 x 5m = 7hr 00m
Hope you like it.
