Abell 33
Abell 33 (sometimes called the Diamond Ring Nebula) is a spherical planetary nebula in the southern constellation of Hydra about 2,700 light years distant. It has been described as a diamond ring due to the bright star (HD83535) at its rim. This star is not part of the nebula, being in front of it in our line of sight. The inner structure has similar dark and light features as the northern Owl planetary nebula, M97. The outer envelope is a distinct rim. The primary color is due to strong emission of oxygen (OIII). The hydrogen (Ha) signal is somewhat weaker.
Just thought I would add this by way of explanation:
A planetary nebula, abbreviated as PN or plural PNe, is a type of emission nebula consisting of an expanding, glowing shell of ionized gas ejected from red giant stars late in their lives.
The term "planetary nebula" is arguably a misnomer, since this phenomenon is not associated with observations of actual planets, and perhaps was derived from the planet-like round shape of these nebulae as observed by astronomers through early telescopes. The term may have originated in the 1780s with the English astronomer William Herschel who described these nebulae as resembling planets; however, as early as January 1779, the French astronomer Antoine Darquier de Pellepoix described in his observations of the Ring Nebula, "...a very dim but perfectly outlined; it is as large as Jupiter and resembles a fading planet". Whatever the true origin of the term, the label "planetary nebula" became ingrained in the terminology used by astronomers to categorize these types of nebulae, and is still used by astronomers today.
Most planetary nebulae form at the end of the star's life, and are a relatively short-lived phenomenon, lasting perhaps a few tens of thousands of years, compared to a typical stellar lifetime spanning several billion years. Once most of the red giant's atmosphere is dissipated, ultraviolet radiation from the hot luminous core, called a planetary nebula nucleus (PNN), ionizes the ejected material. Absorbed ultraviolet light then energises the shell of nebulous gas around the central star, causing it to appear as a brightly coloured planetary nebula.
Imaging telescopes or lenses: Takahashi FSQ130ED
Imaging cameras: QSI 6120i
Mounts: Takahashi EM 400 Temma 2M
Guiding telescopes or lenses: Takahashi FS60CB
Guiding cameras: QHY CCD QHY 5 II
Focal Extender / Reducer: None
Software: Sequence Generator Pro SGP (for capture) PHD 2 (guiding), Astro Pixel Processor & PixInsight,
Filters: Astrodon Ha (3nm), Astrodon OIII (3nm), Astrodon SII (3nm), Astrodon RGB
Accessories: Robofocus Focuser, ATIK EFW3
Original Resolution: 1800 x 1200
Dates: 11th Jan 2019 - 14th Jan 2019
Frames:
Astrodon Ha 9 x 20'
Astrodon OIII 12 x 15'
Astrodon SII 8 x 15'
Astrodon RGB 3 x 18 x 5'
Total integration = 12.5 hours.
Center (RA, Dec): (144.786, -2.809)
Center (RA, hms): 09h 39m 08.586s
Center (Dec, dms): -02° 48' 31.340"
Size: 49.4 x 32.9 arcmin
Radius: 0.494 deg
Pixel scale: 1.32 arcsec/pixel
Orientation: Up is 272 degrees E of N
Just thought I would add this by way of explanation:
A planetary nebula, abbreviated as PN or plural PNe, is a type of emission nebula consisting of an expanding, glowing shell of ionized gas ejected from red giant stars late in their lives.
The term "planetary nebula" is arguably a misnomer, since this phenomenon is not associated with observations of actual planets, and perhaps was derived from the planet-like round shape of these nebulae as observed by astronomers through early telescopes. The term may have originated in the 1780s with the English astronomer William Herschel who described these nebulae as resembling planets; however, as early as January 1779, the French astronomer Antoine Darquier de Pellepoix described in his observations of the Ring Nebula, "...a very dim but perfectly outlined; it is as large as Jupiter and resembles a fading planet". Whatever the true origin of the term, the label "planetary nebula" became ingrained in the terminology used by astronomers to categorize these types of nebulae, and is still used by astronomers today.
Most planetary nebulae form at the end of the star's life, and are a relatively short-lived phenomenon, lasting perhaps a few tens of thousands of years, compared to a typical stellar lifetime spanning several billion years. Once most of the red giant's atmosphere is dissipated, ultraviolet radiation from the hot luminous core, called a planetary nebula nucleus (PNN), ionizes the ejected material. Absorbed ultraviolet light then energises the shell of nebulous gas around the central star, causing it to appear as a brightly coloured planetary nebula.
Imaging telescopes or lenses: Takahashi FSQ130ED
Imaging cameras: QSI 6120i
Mounts: Takahashi EM 400 Temma 2M
Guiding telescopes or lenses: Takahashi FS60CB
Guiding cameras: QHY CCD QHY 5 II
Focal Extender / Reducer: None
Software: Sequence Generator Pro SGP (for capture) PHD 2 (guiding), Astro Pixel Processor & PixInsight,
Filters: Astrodon Ha (3nm), Astrodon OIII (3nm), Astrodon SII (3nm), Astrodon RGB
Accessories: Robofocus Focuser, ATIK EFW3
Original Resolution: 1800 x 1200
Dates: 11th Jan 2019 - 14th Jan 2019
Frames:
Astrodon Ha 9 x 20'
Astrodon OIII 12 x 15'
Astrodon SII 8 x 15'
Astrodon RGB 3 x 18 x 5'
Total integration = 12.5 hours.
Center (RA, Dec): (144.786, -2.809)
Center (RA, hms): 09h 39m 08.586s
Center (Dec, dms): -02° 48' 31.340"
Size: 49.4 x 32.9 arcmin
Radius: 0.494 deg
Pixel scale: 1.32 arcsec/pixel
Orientation: Up is 272 degrees E of N
Sky Map
Annotated Image
