NGC7380 Wizard Nebula

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2012/07/22 - Finally a clear night after 3 weeks of clouds. Too bad transparancy became bad very fast, so I could only add 1 hydrogen-alpha subframe to my old dataset. I tweaked some parameters of PHD to improve my guiding. I increased min. motion and dropped aggressiveness, and as a result my guiding RMS dropped from 0.41 to 0.25px.

NGC 7380 (also known as the Wizard Nebula) is an open cluster discovered by Caroline Herschel in 1787. William Herschel included his sister's discovery in his catalog, and labelled it H VIII.77. It is also known as 142 in the 1959 Sharpless catalog (Sh2-142). This reasonably large nebula is located in Cepheus.

Object information
Name : NGC7380 Wizard Nebula
Type : Nebula
Constellation : Cepheus
Distance : 7.200 light-year
Apparent dimensions : 25'
Apparent magnitude : 7.20

Image information
Image date : 2012/07/22, 2012/07/21, 2012/07/07
Right ascension : 22:47:0.000
Declination : 58°6' 0.00"
Focal length : 0.00 mm
Focal ratio : 
Image resolution : 0.000 arcsec/pixel
Field of view : 
Sky quality : 19.77 magnitude/square arcsecond
Guiding rms : 0.25 x 2 = 0.5 x guiding imagescale 1.3 arcsec/pixel = 0.65 arcsec
Sensor temperature : 0°C
Light frames : 10 hours and 15 minutes total exposure time
14x 900 sec. hydrogen-alpha unbinned
13x 900 sec. oxygen-III unbinned
14x 900 sec. sulfur-II unbinned
Image acquisition scripted with Nebulosity v3
Auto-guiding with PHD (medium dither, settle < 0.3)
Bias frames : 100x unbinned
Dark frames : Bap pixel map
Flat frames : 5x hydrogen-alpha unbinned
5x oxygen-III unbinned
5x sulfur-II unbinned
Created with Gerd Neumann Aurora flatfield panel
Processing : PixInsight for calibration (bias frames, bad pixel map and flat frames), alignment and integration.
Adobe Photoshop CS6 for final touch.

Equipment information
Telescope : Sky-Watcher BKP250 10" 1200mm f/4.8 Newtonian
Corrector : Guan Sheng Optical 2" coma corrector and field flattener
Focuser : Moonlite CR newtonian focuser with DC motor and USBnFocus adapter
Mount : Sky-Watcher NEQ6-Pro german equatorial mount controlled with EQMOD via HiTec Astro EQDir
Camera : QSI 683wsg-8 cooled CCD camera with Kodak KAF-8300 sensor and Off Axis Guide (OAG) port
Guidecamera : Starlight Xpress Lodestar autoguider
Filters : Astrodon Tru-Balance E-Series LRGB & Astrodon 3nm H-α, 3nm O-III, 3nm S-II and 3nm N-II
Observatory site : Etten-Leur, The Netherlands