Ou4 - The Giant Squid

in Cepheus

Ou4 - The Giant Squid
Éder Iván

This squid-shaped turquoise nebula was discovered by a French amateur astronomer Nicolas Outters in 2011. It sits in the center of a much larger Hydrogen cloud catalogued as Sh-129.  This squid is a very large and very faint nebulosity, needs very long exposure time and a special narrowband filter to capture. With over 92 hours, this is far the longest total exposure time I have ever taken for a single object. I captured the squid using my 300 mm telescope through an OIII filter with over 60 hours of exposures. Then I used my smaller 200mm scope to get a wider field to image the red Hydrogen cloud (through Ha filter) and stars (LRGB filters) with 32 hours of integration time.

Image details

200/750 Newton, and 300/1200 Newton with 3" Wynne-corrector
ASI2600MM Pro, Ha, OIII and LRGB filters
Fornax 51 + Boxdörfer DynoStar
Exposure time, filters:
92 hours total
Location, date:
Budakalász (Hungary), during August - September 2021
Observing conditions:
Transparency: 3 - 4/10, Seeing: 3 - 6/10
ImagesPlus, Registar, Pixinsight LE, Photoshop

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