NGC2403 Spiral Galaxy

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2014/02/02 - Finally, afters months of bad weather I was able to shoot this galaxy. Preparations for the remote robotic setup are finished, so I could setup my own gear again. The ASA DDM60 and 10" RC behaved perfect, resulting in this image.

NGC2403 (also Caldwell 7) is an intermediate spiral galaxy in the constellation Camelopardalis. NGC2403 is an outlying member of the M81 Group, and is approximately 8 million light-years distant. It bears a striking similarity to M33, being about 50,000 light years in diameter and containing numerous star-forming H II regions. The northern spiral arm connects it to nearby galaxy NGC2404. NGC2403 can be observed using 10×50 binoculars.

NGC2403 was discovered by William Herschel in 1788. Allan Sandage detected Cepheid variables in NGC2403 using the Hale telescope, giving it the distinction of being the first galaxy beyond our local group within which a Cepheid was discovered. He derived a distance of a mere 8 thousand light years. Today, it is thought to be a thousand times further away at about 8 million light years (2.5 Mpc).

Object information
Name : NGC2403 Spiral Galaxy
Type : Galaxy
Constellation : Camelopardalis
Distance : 8M light-year
Apparent dimensions : 21'.9 × 12'.3
Apparent magnitude : 8.90

Image information
Image date : 2014/02/02
Right ascension : 7:36:51.031
Declination : 65°35' 50.62"
Focal length : 1381.68 mm
Focal ratio : f/5.44
Image resolution : 0.806 arcsec/pixel
Field of view : 43' 58.5" x 32' 5.1"
Sensor temperature : -30°C
Light frames : 6 hours, 10 minutes total exposure time
13x 600 sec. luminance unbinned
8x 600 sec. RGB unbinned
Image acquisition with CCDAutoPilot and Maxim DL
Auto-guiding with Maxim DL
Auto-focusing with FocusMax
Bias frames : 100x unbinned
Dark frames : None
Flat frames : 5x luminance unbinned
5x RGB unbinned
Automated sky twilight flats with CCDAutoPilot
Processing : PixInsight for calibration, alignment and integration.
Adobe Photoshop CS6 for final touch.

Equipment information
Telescope : Robtics 10" 2000mm f/8 Ritchey Chretien
Corrector : Astro-Physics CCDT67 Focal Reducer
Focuser : Moonlite CS Ritchey Chretien focuser with high resolution stepper motor
Mount : ASA DDM60 Pro direct drive german equatorial mount controlled with AutoSlew
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