Hemisphere:  Northern  ·  Constellation: Cygnus (Cyg)
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Sh2-123 / StDr17 (Tick Nebula), 



    
        

            Chris Sullivan
Sh2-123 / StDr17 (Tick Nebula)
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Sh2-123 / StDr17 (Tick Nebula)

Getting plate-solving status, please wait...
Sh2-123 / StDr17 (Tick Nebula), 



    
        

            Chris Sullivan
Sh2-123 / StDr17 (Tick Nebula)
Powered byPixInsight

Sh2-123 / StDr17 (Tick Nebula)

Technical card

Imaging telescopes or lenses: SharpStar 15028HNT

Imaging cameras: QHYCCD 183

Mounts: SkyWatcher AZ-EQ5

Guiding telescopes or lenses: Orion Thin Off-Axis Guider (TOAG)

Guiding cameras: ZWO 290MM Mini

Filters: Optolong Blue 1.25"  ·  Optolong Green 1.25"  ·  QHYCCD QHYCFW3S - 3rd Generation Small Thin 7 position Filter Wheel  ·  Optolong Red 1.25"  ·  Baader f/2 Highspeed 1.25" H-Alpha Filter


Dates:July 3, 2020July 12, 2020July 15, 2020July 30, 2020Aug. 10, 2020Aug. 11, 2020Aug. 20, 2020Aug. 25, 2020Sept. 6, 2020Sept. 7, 2020

Frames:
Baader f/2 Highspeed 1.25" H-Alpha Filter: 115x600" (19h 10')
Optolong Blue 1.25": 103x30" (51' 30")
Optolong Green 1.25": 100x30" (50')
Optolong Red 1.25": 104x30" (52')

Integration: 21h 43' 30"

Avg. Moon age: 15.95 days

Avg. Moon phase: 58.24%

Bortle Dark-Sky Scale: 7.50


Basic astrometry details

Astrometry.net job: 3833404

RA center: 21h 42' 26"

DEC center: +44° 30' 3"

Pixel scale: 1.199 arcsec/pixel

Orientation: 182.001 degrees

Field radius: 1.042 degrees


Resolution: 3465x5213

Locations: Home Roof (Bortle 7-8 / Est. Sky Quality: 18.53), Springfield, PA, United States

Data source: Backyard

Description

Strottner-Drechsler 17 (more widely known as Sharpless 2-123) is a planetary nebula that was previously thought to be an HII region. It was only this past January that spectroscopy confirmed that StDr 17 / Sh 2-123 was indeed a planetary nebula. If your French is good, check out Andreas Bringmann's image, which contains the spectroscopic confirmation write-up. If your French isn't great, the key part by Quentin Parker is in English and it reads: "An HII region ID is ruled out by the very high [NII] to H-alpha ratio in the spectra despite the fact it is among areas of extended nebulosity. The nature of this object (and colours) are distinct. I think it is a highly evolved bipolar PN with a likely high mass progenitor of Type I chemistry."

This one is fainter than I was expecting. It was also the first time I've ever added data and not been able to see any difference from my previous test stack - I originally planned on getting 25 hours of hydrogen, but my last 3.5 hours did nothing to improve the SNR (at least that I could see).

I want to dedicate this one to Goofi, whose image of this target - the first one on Astrobin - inspired me to do it years ago. It took me way too long to get around to this target and I always planned on writing to him to ask him for some pointers before I started shooting it, but unfortunately we lost him before I got around to it. I'm bummed I never got a chance to talk with him, but even without personal contact, he definitely made his mark on me and the astro community as a whole (especially over on Cloudy Nights).

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