Ou4 The Squid Nebula...Sh2-129, LBN 445, 449, 453 (Alex Woronow)

Ou4 The Squid Nebula...Sh2-129, LBN 445, 449, 453

Ou4 (the Squid Nebula) and Sh2-129, LBN 445,449,453

OTA: RH-305 (12” f/3.5)

Camera: SBIG STX-16803

Observatory: Deep Sky West

EXPOSURES:

Red: 14 x 300 seconds

Blue: 8 x 300

Green: 13 x 300

Luminosity 13 x 300 (see below)

Hydrogen: 19 x 1200

Oxygen: 23 x 1200

Total exposure ~18 hours

Image Width: ~1.75 deg

Processed by Alex Woronow using PixInsight, StarNet++ and custom Matlab code. Processed in 2019;

North is toward the bottom

Ou4, (the blue nebula) was discovered in 2011 by an amateur astronomer, Nicolas Outters. Its faintness and the fact that it is emitting faint light primarily in the OIII (blue-green part of the spectrum) made it difficult to detect. The surrounding red hydrogen-emission nebula (Sh2-129) also known as the ‘Flying Bat Nebula’.

Recent studies (R.L.M. Corradi, et al, 2014) suggest that OU4 lies within Sh2-129 at a distance of about 2,300 light-years. At this distance, the Squid would be about 50 light-years in length (projected size??). OU4 possibly results from an outflow of gasses from the triple star system, HR8119, located in the center of the nebula. The Squid has an estimated age of only 90,000 years, based on its measured expansion rate.

Processing: The Luminosity images were not used in this version. The Hydrogen alpha was blended into the red channel using an algorithm that proportions the hydrogen contribution according to the relative exposure times and bandwidths of the red and Ha filters. The same was done with the OIII with equal contributions going into the blue and green channels.

Sharpening utilized the Local Laplacian Pyramid algorithm based on Paris, et al. 2011 (Proc. SIGGRAPH, 2011)and implemented in Matlab. The StarNet++ used for this image was the recently-available version for PixInsight procedure.

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Status	Advanced success
Started	...
Astrometry.net job	2765448
PixInsight job	TVIT8E2IUM5NSNRYQOZUADJW7K3M3BZK
PixInsight queue size	n/a
PixInsight stage	n/a

RA (center)	21h12m20s.16
RA (top/left)	21h05m46s.98
RA (top/right)	21h19m10s.60
RA (bottom/right)	21h19m14s.62
RA (bottom/left)	21h05m08s.95

Dec (center)	+59°56′20″.1
Dec (top/left)	+59°03′06″.1
Dec (top/right)	+59°05′09″.5
Dec (bottom/right)	+60°48′20″.10
Dec (bottom/left)	+60°46′10″.9

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