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NGC 281 (Sh 2-184, IC 11, LBN 616, Pacman Nebula) - Emission Nebula, and IC 1590 - Open Cluster in Cassiopeia

L-SHO combination (Click for a larger view 1600 x 1600 px)

 

L-HSO combination (Click for a larger view 1600 x 1600 px)

 

Details

NGC 281 (Sh 2-184, IC 11, LBN 616, Pacman Nebula) - Emission Nebula, and IC 1590 - Open Cluster in Cassiopeia

NGC 281 (Sharpless 184) is a region of star formation about 10000 light years away. The complex is located in the Perseus arm of our galaxy and its visible structure spans about 60 light years. The nebula contains a variety of pillars and dark globules. NGC 281 is a relatively bright HII region. Dark globules known as Bok globules are presented in the emission nebula. These compact dark structures were first described by the astronomer Bart Bok (1906-1983) in the 1940's. Bok Globules are small dark clouds of gas and dust that are found in HII regions and typically have a mass of about 10 to 50 solar masses. The young galactic open cluster IC 1590 is formed within the nebulosity of NGC 281, the H II region S184. That cluster's young, massive stars ultimately power the pervasive nebular glow. The shapes overhanging around the central region of NGC 281 are sculpted from dense dust globules, eroded by intense, energetic winds and radiation from the hot cluster stars. The brightest star of the system is the O5.5 giant HD 5005. The formation of the stars of IC 1590 began 3.5 million years ago and likely continues today.

North is up. The Horizontal FOV is about 38' (slight crop from original FOV). The image almost centered at:

Right Ascension 0 : 52.8 (h:m)
Declination +56 : 37 (deg:m)
Distance 10.0 (kly)
Brightness 7 (mag)
Apparent Dimension

35' x 35' (arc min)

Seeing: Pickering 8 rating - Very Good to Excellent
Optic(s): RC 12" with Astro-Physics corrector @ f/5
Mount: ASA DDM85 Premium
Camera: ATIK 4000 - monochrome CCD – 2048 x 2048 px ; 16x16 mm; 7.4 µm x 7.4 µm
Filters: Astronomik Ha, OIII, SII, SupaSlim TrueTechnology Computerized Filter Wheel
Dates/Times: 2012-08-21
Location: Rozhen Observatory, BG, longitude: E 24 44' 18", latitude: N 41 41' 42"
Exposure Details:

Ha = 120 min, SII = 60 min, OIII = 60 min, L=60 min (Bin 1), subs. 15 min, Total Exposure Time - 300 min

More details: Dark and flat frames reduction
Guiding: All subexposures are unguided
Processing:

PixInsight / PS

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All Contents copyright Velimir Popov unless otherwise noted.