Orion and Sirius rising into a moonlit winter sky, on a chilly (-20°C) winter night on January 28, 2023. Below Orion is Sirius in Canis Major. The red giant Betelgeuse and the blue giant Rigel stand out nicely above and below the Belt. Light from the first quarter Moon off frame illuminates the landscape. This serves as a good illustration of how the Belt stars in Orion point down to Sirius. The minor constellation of Lepus the Hare is below Orion. And the "Pi" stars that form the arc of the shield of Orion show up to the right of Orion. This is a stack of 4 x 30-second exposures for the sky with the camera tracking the sky, blended with a stack of 4 x 30-second untracked exposures for the ground. All with the Canon RF28-70mm lens at 33mm and f/2.8 and Canon R5 at ISO 200. A tracked exposure through the Alyn Wallace/Kase StarGlow filter added the star glows, and for artistic effect I also added diffraction spikes on the stars with the AstronomyTools actions. A mild Orton glow added with Luminar Neo.
Comet C/2022 E3 (ZTF) on the night of January 24, 2023. This was the night Earth crossed the plane of the comet's orbit. The dust tail of the comet showed a slight anti-tail spike ahead of the comet's greenish coma, but not as prominently as it had appeared two nights earlier. What was much more visible this night (at least to the camera) was the long thin and bluish ion tail stretching directly back from the comet away from the Sun. The coma of the comet is strongly cyan or green from glowing diatomic carbon molecules, common for comets. The comet was discovered in March 2022 at the Zwicky Transient Facility telescope, thus the ZTF name. This is a stack of 4 x 1-minute exposures through the William Optics 51mm RedCat astrograph at f/4.9 (so 250mm focal length) and with the stock Canon R5 camera at ISO 3200. The mount was guided on the stars — in stacking just 4 exposures taken over 4 minutes the comet didn't move enough to significantly blur details at this short focal length. I made no attempt to separately align the comet and the stars. The field is 8° by 5.5°, so similar to a binocular field of view. The comet was easy to see in binoculars as a grey glow, and it was barely naked eye but only if you knew exactly where to look.
A widefield view of Orion's Belt and Sword showing the complex of nebulosity in the area. The three Belt stars are at top (L to R): Alnitak, Alnilam and Mintaka, with the dark Horsehead Nebula (B33) below Alnitak. Above Alnitak is the pinkish Flame Nebula, NGC 2024. At bottom are Messiers 42 and 43, making up the Orion Nebula, with the bluish Running Man Nebula above it, aka NGC 1973-5-7. Above it is the star cluster NGC 1981. Messier 78 is just on frame at upper left. Numerous other bits of emission and reflection nebulas populate the field amid a backdrop of faint emission nebulosity. The stars around the Belt belong to the large star cluster Collinder 70. This is a blend of two stacks of images: 15 x 8 minutes through an IDAS NBX dual narrowband filter to bring out the faint nebulosity, and 15 x 4-minutes with no filter for the more natural star colours and colours of the Orion, Flame and Horsehead (IC 434) Nebulas. So a total of 3 hours of exposure time. I did not take shorter exposures for the Orion Nebula core. All were with the William Optics RedCat 51mm astrograph at f/4.9 and filter-modified (by AstroGear) Canon EOS R at ISO 3200 for the filtered shots and ISO 800 for the unfiltered shots. Taken from home January 22, 2023 on a rare clear winter night. Autoguided and dithered with the Lacerta MGEN3 autoguider. No darks or LENR employed. All stacking, alignment and masking in Photoshop. Luminosity masks with Lumenzia helped bring out the nebulosity, as did a mild application of the Nebula FIlter action in the PhotoKemi StarTools Actions set. Noise reduction with RC-Astro Noise XTerminator. The filtered set has had all the stars removed using RC-Astro Star XTerminator, so it contributed just the nebulosity, Stars come from the unfiltered set for tighter stars with more natural colours.
