Image awarded APOD BRASIL on 08May25
Image awarded APOD GrAG on 18May25
Sh2-91 is an emission nebula visible in the constellation Cygnus.
The nebula is located about 1 ° north of the famous optical double Albireo (β Cygni), a magnitude 3 star also visible from urban centres. Despite its large size, Sh2-91 is very faint and its observation is extremely difficult, as is its photographic recovery, which can be done through the use of special filters. The best time to observe it in the evening sky is from June to December, especially from boreal regions.
Sh2-91 constitutes the most extended southern filament of the supernova remnant G65.2+5.7, located about 2610 light years from the Solar System in a Galactic region rich in dense molecular clouds, on which lies the Great Rift. G65.2+5.7 is in fact a super bubble extended over about 587 light years and located about 261 light years north of the Galactic plane. Sh2-91 shows a strong polarization, indicating the presence of a strong magnetic field.
The entire SNR is oval in shape, and about the same size as the much better-known Veil Nebula, which is also found in the Cygnus. However, G 65.3 + 5.7 is considerably fainter than the Veil Nebula. Probably for this reason, not that many images of this region are seen……but is now perhaps becoming a more popular challenge for Narrow Band imagers with CMOS cameras.
Imaging telescope: Takahashi FSQ130ED
Imaging camera: ASI 2600MM
Mount: JTW Trident P75
Guiding telescope: Takahashi FS60CB
Guiding camera: QHY 5L II M
Focal Extender / Reducer: 0.73X
Software: Sequence Generator Pro SGP (for capture) PHD 2 (guiding), Astro Pixel Processor, PixInsight.
Filters: Astrodon Ha (3nm), Astrodon OIII (3nm), Astrodon RGB.
Accessories: Robofocus Focuser controlled by Lunatico Armadillo, ATIK EFW 3, RB Focus Gaius, RB Focus Excalibur.
Dates: 18th Apr. - 27th Apr. 2025
Frames: (Total)
Astrodon Ha 78 x 600"
Astrodon OIII 66 x 600"
Astrodon RGB 3 x 20 x 60"
Total integration = 25 Hours.
Center (RA, Dec): (293.893, 30.300)
Center (RA, hms): 19h 35m 34.429s
Center (Dec, dms): +30° 18' 00.262"
Size: 2.72 x 1.81 deg
Radius: 1.636 deg
Pixel scale: 1.63 arcsec/pixel
The nebula is located about 1 ° north of the famous optical double Albireo (β Cygni), a magnitude 3 star also visible from urban centres. Despite its large size, Sh2-91 is very faint and its observation is extremely difficult, as is its photographic recovery, which can be done through the use of special filters. The best time to observe it in the evening sky is from June to December, especially from boreal regions.
Sh2-91 constitutes the most extended southern filament of the supernova remnant G65.2+5.7, located about 2610 light years from the Solar System in a Galactic region rich in dense molecular clouds, on which lies the Great Rift. G65.2+5.7 is in fact a super bubble extended over about 587 light years and located about 261 light years north of the Galactic plane. Sh2-91 shows a strong polarization, indicating the presence of a strong magnetic field.
The entire SNR is oval in shape, and about the same size as the much better-known Veil Nebula, which is also found in the Cygnus. However, G 65.3 + 5.7 is considerably fainter than the Veil Nebula. Probably for this reason, not that many images of this region are seen……but is now perhaps becoming a more popular challenge for Narrow Band imagers with CMOS cameras.
Imaging telescope: Takahashi FSQ130ED
Imaging camera: ASI 2600MM
Mount: JTW Trident P75
Guiding telescope: Takahashi FS60CB
Guiding camera: QHY 5L II M
Focal Extender / Reducer: 0.73X
Software: Sequence Generator Pro SGP (for capture) PHD 2 (guiding), Astro Pixel Processor, PixInsight.
Filters: Astrodon Ha (3nm), Astrodon OIII (3nm), Astrodon RGB.
Accessories: Robofocus Focuser controlled by Lunatico Armadillo, ATIK EFW 3, RB Focus Gaius, RB Focus Excalibur.
Dates: 18th Apr. - 27th Apr. 2025
Frames: (Total)
Astrodon Ha 78 x 600"
Astrodon OIII 66 x 600"
Astrodon RGB 3 x 20 x 60"
Total integration = 25 Hours.
Center (RA, Dec): (293.893, 30.300)
Center (RA, hms): 19h 35m 34.429s
Center (Dec, dms): +30° 18' 00.262"
Size: 2.72 x 1.81 deg
Radius: 1.636 deg
Pixel scale: 1.63 arcsec/pixel
Sky Map & Finding Chart
Ha, OIII & RGB in the Image:
Annotated Image:
