Deep Sky Object in Summer
Vast Nebulosity around zeta Oph(Sh2-27)


Date & Time: May 1 2014, from 24:22 to 25:03 JST(+0900)
Mosaic of 2 flames of 8min.×3shots
Optical: AF zoom-Nikkor ED 80-200mmF2.8 (f=135mm, Aperture: F2.8)
with Astronomik CLS-CCD filter
Auto-guided with TAKAHASHI EM200 Equatorial
Digital Camera: Canon EOS 550D (Remodeled)
Location: Koumi town, Nagano pref.

Camera Settings: Recording Format...14bit CCD-RAW, converted to 16bit TIFF(5184×3456)
CCD Sensitivity...ISO800




Sh2-27 / Diffused Nebula, type 6 E
R.A.16h 35m (Rough position)
Dec.-10° 30' (Rough position)
Apparent Sizeabout 660×540'
Real Size80 light yrs.
Magnitude-
Distance550 light yrs.
Other IDsLBN 24, Gum73
A gigantic and round diffused nebula is spread around zeta Oph, which marks a foot of Serpent Holder. Of course the nebula is invisible for our naked eyes. We can see the nebula only on long exposed films under good conditioned sky with medium-ranged telephoto lenses like the Angelfish nebula in Orion. Many sky atlases have forgotten to record the shape of this nebula, it can be said that the nebula is not well known. And the nebula was discovered after astrophotography has been developed, has no major catalogue numbers. Though it's getting harder and harder to capture it under recent terrible light pollution year after year, this picture shows you some complicated structures of lanes of dark nebulae and various shading.




Sh2-22

Around Sh2-24, Sh2-33


Copyright(c) 2014 by Naoyuki Kurita, All rights reserved.
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