Deep Sky Object in Autumn
Around Sh2-176 (Planetary Nebula in Cassiopeia)
Click on image to enlarge
|Date & Time: ||Dec 24 2022, from 21:21 to 22:34 JST(+0900)
|Composed 10 shots with 8 minutes exposed|
|Optical: ||TAKAHASHI 16cm(6.3") epsilon (f=530mm, F3.3)
|with IDAS LPS-D1 Light-pollution suppression filter|
|Auto-guided with TAKAHASHI JP Equatorial+SBIG STV
|CMOS Camera: ||ZWO ASI2600MC Pro (Cooled temp.: -25°C)
|Location: ||Ooizumi, Hokuto city, Yamanashi pref.
|Camera Settings: ||Recording format...16bit FITS, converted to 16bit TIFF(6248×4176)|
|Device Size...23.5×15.7mm, Gain...100|
Sh2-176 is an extraordinary faint planetary nebula positioned at about 1.5 degrees northwest of α-Cas.
The nebula has an apparent diameter of about 12 arc minutes and is emitting reddish Hα light.
Although the nebula has a round shape, we can recognize it like an arc-shaped in brighter southern side.
|Sh2-176 / Planetary Nebula, type 5 E|
|R.A.||00h 31m 53.6s (2000.0)|
|Dec.||+57°22' 33" (2000.0)|
|Real Size||1.6 light yrs.|
|Distance||460 light yrs.|
|Other IDs||LBN 597, PK 120-5.1|
|LBN594 / Reflection Nebula, type 6 R|
|R.A.||00h 28m 39.0s (2000.0)|
|Dec.||+56°42' 50" (2000.0)|
|Other IDs||LBN 595|
It's considered that the Sh2-176 is one of most ancient planetary nebulae,
at the present the gaseous matter emitted from a dead central star has distributed in a diameter of about 1.6 light years.
In this image, you can see a very faint reflection nebula of LBN 594 located about 50 minutes southwest of Sh2-176 at the bottom of the field.
The size is about 2 arc minutes, and you can see that the south side is slightly bluish.