M33 Triangulum Galaxy

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2015/11/06 - We had some issues with our focuser, so I had to reject lots of out-of-focus images. With the remaining images I managed to create this image of M33.

The Triangulum Galaxy is a spiral galaxy approximately 3 million light-years (ly) from Earth in the constellation Triangulum. It is catalogued as Messier 33 or NGC 598, and is sometimes informally referred to as the Pinwheel Galaxy, a nickname it shares with Messier 101. The Triangulum Galaxy is the third-largest member of the Local Group of galaxies, which includes the Milky Way, the Andromeda Galaxy and about 44 other smaller galaxies. It is one of the most distant permanent objects that can be viewed with the naked eye.

The galaxy is the smallest spiral galaxy in the Local Group and it is believed to be a satellite of the Andromeda Galaxy due to their interactions, velocities and proximity to one another in the night sky. It also has an H-II nucleus.


Object information
Name : M33 Triangulum Galaxy
Type : Galaxy
Constellation : Triangulum
Distance : 2.380K light-year
Apparent dimensions : 70'.8 × 41'.7
Apparent magnitude : 5.72

Image information
Image date : 2015/11/06, 2015/11/07, 2015/11/08, 2015/11/10, 2015/11/11, 2015/11/12
Right ascension : 1:33:55.786
Declination : 30°38' 58.89"
Focal length : 1685.66 mm
Focal ratio : f/6.64
Image resolution : 0.661 arcsec/pixel
Field of view : 35' 36.3" x 27' 7.5"
Sky quality : 21.5 mag/arcsecond2
Sensor temperature : -20°C
Light frames : 18 hours, 30 minutes total exposure time
35x 900 sec. luminance unbinned
18x 900 sec. red unbinned
10x 900 sec. green unbinned
11x 900 sec. blue unbinned
Image acquisition with ACP Observatory Control Software, ACP Scheduler and Maxim DL
Auto-guiding with Maxim DL
Auto-focusing with FocusMax
Bias frames : None
Dark frames : None
Flat frames : None
Processing : PixInsight for calibration, alignment and integration.
Adobe Photoshop CS6 for final touch.

Equipment information
Telescope : Orion Optics 10" ODK
Corrector : None
Focuser : Baader SteelTrack with SteelDrive
Mount : Mesu Mount 200 with Sidereal Technology SiTech Controller
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 : www.sunstarfrance.com, Hautes-Alpes, France