Deep Sky Object in Autumn
NGC7789 (Open Cluster in Cassiopeia)


Date & Time: Oct 11 2015, from 21:51 to 22:15 JST(+0900)
Composed 4 shots with 8 minutes exposed
Optical: TAKAHASHI 16cm(6.3") epsilon (f=530mm, F3.3)
with IDAS LPS-P2-FF Light-pollution suppression filter
Auto-guided with TAKAHASHI JP Equatorial & SBIG STV
Digital Camera: Canon EOS 550D (Remodeled)
Location: Ooizumi, Hokuto city, Yamanashi pref.

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


NGC7789 / Open Cluster, type e, II 2 r
R.A.23h 57m 0.0s (2000.0)
Dec.+56° 44' 00" (2000.0)
Apparent Size30.0'
Real Size113 light yrs.
# of Stars255
Magnitude9.6
Distance13,000 light yrs.
NGC7789 is a rich open cluster of over a thousand fine stars. It's about three degrees SW of beta Cas that marks a western tip of W-shaped asterism. The cluster has a diameter of about 30 arc minutes and almost all of member stars are 11th magnitude or so. But those dimmed members have almost same brightness, and can be enjoyed the beauty of complicated structure of cluster with medium magnification.
Though this cluster has as same size as that of the moon, it looks like a diffused nebula through binoculars. The cluster is estimated about 13 thousand light years away.



NGC7686
Around NGC7790

Copyright(c) 2015 by Naoyuki Kurita, All rights reserved.
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