Ou-4 Bipolar Nebula

Ou-4 Bipolar Nebula

Giant Squid Nebula in Cepheus

Constellation: Cepheus
Ra: 21h 11m 37s
Dec: +60d 0m 39s
Distance: 2,300 light years
Image Size: 31' x 31'
North: Up left; East down left



Ou-4 is a faint, bipolar nebula discovered by French amateur astronomer Nicolas Outters in 2011. Its full length covers 1.2 degrees in the sky and is thus about 2.5 times longer than shown in the above high-resolution image that shows the central part. It is located within the HII region of Sharpless2-129 in Cepheus at a distance of 2,300 light years. At that distance, it is determined to be 50 light years across. It is referred to as the Giant Squid Nebula or the Flying Bat Nebula, which is better defined in wide-field images. Its bipolar tubular structure is similar to planetary nebula KjPn 8 which I’ve previously imaged here. It is thought that this bipolar structure came from the outflow ejected from one of the stars in a multiple-star system about 90,000 years ago. Ou-4 is primarily defined by its OIII emission at optical wavelengths as a blue-green color in the above image. The reddish background color comes from H-a emission of Sh-129. These nebular and background details in this 42 hour image came from using 3 nm OIII and H-a filters color-mapped as described above to provide natural color. 3 hours of RGB data were added for star colors. This is a collaboration with Josep Drudis.

Exposure: 42.33 hrs Total: 28 hrs OIII, 11.33 hrs H-a, 3 hrs RGB
Telescope: Planewave CDK24 (61 cm) f/6.5 reflector
Mount: Planewave L-600 Direct Drive
Oag: Astrodon MonsterMOAG
Acquisition: ACP
Calibration: CCD Stack 2.0
Observatory Site: Curiosity2, New Mexico Skies, Mayhill, NM
Camera: FLI PL16803
Filters: Astrodon Gen 2 E-Series RGB, 3 nm OIII and H-a
Guider: Starlight Xpress Lodestar SX2
Camera Operation: MaximDL
Processing: CCD Stack 2.0; Photoshop CC 2021
Image Date: 09/11/2021 - 09/27/2021

Submit a Comment

Your email address will not be published. Required fields are marked *

The reCAPTCHA verification period has expired. Please reload the page.