La zone colorée mais obscure de la voie lactée de Cepheus qui contient la nébuleuse du lion (en bas), une région émettant à la fois rouge hydrogène-alpha lumière et
3570 x 5400 px | 30,2 x 45,7 cm | 11,9 x 18 inches | 300dpi
Date de la prise de vue:
31 octobre 2021
Informations supplémentaires:
The colourful but obscure area in the Cepheus Milky Way that contains the Lion Nebula (at bottom), a region emitting both red Hydrogen-alpha light and cyan Oxygen III light. It is a nebula that only recently became popular as an astrophoto target, perhaps because of its new nickname and from the use of narrowband filters to bring it out. It is not in the popular Messier, NGC or IC catalogues but is officially labeled as Sharpless 2-132. Meanwhile at top, the brightest nebula is the even more obscure Sharpless 2-135, alongside a very faint band of nebulosity that might not have a catalogue number — I couldn't find one! The nebulosity at top is a deeper red than the Lion Nebula, as the top area of sky contains more dark dust absorbing and reddening the nebulosity and also decreasing the star density and yellowing the sky compared to the richer, brighter and bluer region at bottom to the south around the Lion. There is a very small (like a fuzzy red star) planetary nebula just right of centre called the Little Ring Nebula, or M2-51, from the Minkowski catalogue. Another tiny planetary in the extreme lower left corner is Abell 79. The field of view here is 5° by 3.3°, with north up. The star at upper left is the famous variable and double star Delta Cephei. The yellow star at right is Zeta Cephei. This is a stack of 48 sub-frames taken over two nights, all with the SharpStar 94mm EDPH refractor at f/4.4 and the Canon Ra camera: - A stack of 16 x 8-minute exposures with a "clear" filter, an Astronomik UV/IR cut filter at ISO 800 - A stack of 16 x 12-minute exposures through an IDAS NB1 dual-narrowband filter at ISO 1600 - A stack of 16 x 16-minute exposures through an IDAS NBX dual ultra-narrowband filter at ISO 1600. This set was shot on night #2 as there was not enough time to shoot it on the same night at the other sets. The clear filter set contributes the sky background and natural star colours. The NB1 filter set contributes most of the red H-alpha co
