A 45° panorama of the massive "grand display" of noctilucent clouds at dusk on June 16, 2021 from "One Tree Hill" near home in southern Alberta. This display was bright and extensive at dusk on June 16, and re-appeared over much of the northeastern sky at dawn on June 17. Note the colours — with the NLCs having a reddish tinge at the top where sunlight is reddened as the Sun sets from that altitude and location of the clouds. The lower areas of NLCs often appear green as well. But the main colour of NLCs is electric blue, very much so this night when they were so bright. The sharp dark edge in the clouds at left is real; it is not a stitching artifact. Capella is the brightest star to the right of the lone tree. This is a panorama of 6 segments with the 85mm Samyang lens and Canon R6, stitched with Adobe Camera Raw.
A 90° panorama of the massive "grand display" of noctilucent clouds at dusk on June 16, 2021 from "One Tree Hill" near home in southern Alberta. This display was bright and extensive at dusk on June 16, and re-appeared over much of the northeastern sky at dawn on June 17. This shows the arc of the NLCs, defined at the top by the edge where sunlight is no longer illuminating the clouds, an edge that drops in altitude as the Sun itself drops farther below the horizon. Capella is at centre, Leo and Regulus at far left, and Perseus at right of centre. The main colour of NLCs is electric blue, very much so this night when they were so bright. This is a panorama of 10 segments with the 50mm Sigma lens and Canon R6, stitched with Adobe Camera Raw.
This is the supernova remnant in Cygnus known as the Veil Nebula, here in its entirety, from the eastern arc at left, catalogued as NGC 6992/5, to the western arc at right, NGC 6960, running past the star 52 Cygni. At top is the wedge-shaped "Pickering's Triangle.," but discovered photographically by Wiliamina Fleming, one of the Harvard "computers." The field is filled with lots of little nebula bits and shrapnel-like fragments. All are remains of a star that exploded as a supernova some 10,000 to 20,000 years ago and is about 2,400 light years away. The red is emission from ionized hydrogen, the cyan emission from ionized oxygen. This nebula shows a lot of oxygen emission at the leading edge of the expanding cloud of debris. This is a blend of three stacks of exposures: -- 10 x 8 minutes at ISO 3200 through an Optolong L-eXtreme very narrowband filter which lets through just green-blue oxygen III and red hydrogen alpha wavelengths -- 8 x 8 minutes at ISO 1600 through an Optolong L-eNhance narrowband filter which lets through a broader bandwidth of light at those two main wavelenths, OIII and Ha -- 8 x 6 minutes at ISO 800 through no filter which records the full spectrum of light All were with the Canon EOS Ra through the SharpStar 94mm apo refractor at f/4.4 with its reducer/flattener and using an AstroHutech filter drawer between the flattener and camera to aid filter swapping. The L-eNhance set was taken June 11 until clouds intervened; the other 2 sets were taken the next night June 12. There was only about 2 hours of semi-darkness at this time of year from my latitude of 51° N. Guiding was with the MGEN3 stand-alone auto-guider (which applied a 5-pixel dither or image shift between each exposure) and William Optics 30mm guidescope. So impressive results less than 2 weeks from solstice at my latitude, made possible by the filters. With the dithering, no LENR or darks were applied, despite this being a warm-ish night. The L-eXtreme set contributes the cyan component; the L-eNhance set contributes the red component best; the clear base layer contributes more normally coloured stars, as the filters tend to discolour the stars and add haloes. All stacking, aligning, blending and masking were with Photoshop, with luminosity masks created with Lumenzia for selected adjustments to regions of different brightnesses. A high pass sharpen also added to the bright areas with another luminosity mask.
