Sh2 with Elmore 3
Sh2-176 is a faint planetary nebula in Cassiopeia. It has a surface brightness of 15.5 mag/arc-sec2 and a hydrogen-rich central star. It was discovered to be a planetary nebula by Sabbadin et al in 1977. It is approximately 490 light-years away with estimates for its age ranging from 24,000 to over 180,000 years old based on the computed kinematics (expansion rate and nebular diameter). Expanding at 19 km/sec, Sh2-176 has been estimated to span 3.1 to over 22.8 light-years across depending on the source. Its asymmetricity is believed to be the result of bow shocks involving the interstellar medium and the planetary nebula itself where, the brighter portion of the nebula represents the interaction of the nebula meeting up against the interstellar medium as it moves through space. The central star associated with Sh2-176 is a blue subdwarf with a magnitude of 18.74.
Elmore 3 is a candidate planetary nebula discovered by David Elmore earlier this year.
Elmore 3 is a candidate planetary nebula discovered by David Elmore earlier this year.

TARGET
Nomenclature: Sh2-176, Elmore 3, El 3
Right Ascension: 00:26:50.07 (El 3) 00:31:48.6 (Sh2-176)
Declination: +56:58:42.7 (El 3) +57:22:58.37 (Sh2-176)
Size: 138 arcsec (El3) 6600 arcsec (Sh2-176)
EQUIPMENT USED
APM TMB LZOS 152 Refractors
Celestron C14 EdgeHD SCT
10Micron GM2000HPS mount
ASA DDM85 mount
QHYCCD QHY600 Pro M camera
Nomenclature: Sh2-176, Elmore 3, El 3
Right Ascension: 00:26:50.07 (El 3) 00:31:48.6 (Sh2-176)
Declination: +56:58:42.7 (El 3) +57:22:58.37 (Sh2-176)
Size: 138 arcsec (El3) 6600 arcsec (Sh2-176)
EQUIPMENT USED
APM TMB LZOS 152 Refractors
Celestron C14 EdgeHD SCT
10Micron GM2000HPS mount
ASA DDM85 mount
QHYCCD QHY600 Pro M camera
IMAGE CAPTURE
OIII: 474x1200" bin 1x1
Ha: 104x300" bin 1x1, 280x120" bin 1x1
Total integration: 33 hours 48 minutes
Pixel scale:1.086 arcsec/pixel
Field radius: 1.134 degrees
Capture dates: 28 September - 24 October 2024
Capture location: Fregenal de la Sierra
OIII: 474x1200" bin 1x1
Ha: 104x300" bin 1x1, 280x120" bin 1x1
Total integration: 33 hours 48 minutes
Pixel scale:1.086 arcsec/pixel
Field radius: 1.134 degrees
Capture dates: 28 September - 24 October 2024
Capture location: Fregenal de la Sierra
IMAGE PROCESSING
Pre-processing: Pixinsight, CCDStack2
Post-processing: Pixinsight, Photoshop CS2
Pre-processing: Pixinsight, CCDStack2
Post-processing: Pixinsight, Photoshop CS2