M33 (NGC 598, Triangulum Galaxy) - Spiral Galaxy , type Sc, in Triangulum.

LHa-HaR-G-B combination - (Click for a larger view 2000 px x 2000 px)

Mouse over to see identifications of objects (see info below)


M33 identification map


M33 (NGC 598, Triangulum Galaxy) - Spiral Galaxy , type Sc, in Triangulum

Probably discovered by Hodierna before 1654. Independently discovered by Charles Messier 1764.

M33 (The Triangulum Galaxy) is the member of our local group of galaxies. It is over 50000 light-years in diameter, the third largest in the Local Group of galaxies - only our own Milky Way and M31 (Andromeda Galaxy) are larger. The popular names of M33 include the Pinwheel Galaxy or Triangulum Galaxy.
The spacious spiral arms of M33 are rich in star forming HII regions. M33 is a faint and extended galaxy with a small, almost starlike nucleus. The light haze consist of faint stars, which shines in the yellowish light. Dark dust lanes can be traces into the nucleus. Unlike many other large galaxies, such as the Milky Way and Andromeda, M33 does not have a supermassive black hole in its center. From the nucleus, spiral arms reach out through the disk, which are populated by young hot blueish stars. They have formed from reddish diffuse nebulae, and indicate activity of star formation. Some of the bluish star clouds and reddish H II regions (diffuse nebulae) have been assigned by own NGC or IC numbers. The brightest and most impressive of M33's HII regions is NGC 604. This massive HII region spans about 1500 light years. There are also a number of globular clusters in the spiral arms.

North is up. The Horizontal FOV is about 40' . The image almost centered at:

Right Ascension 01:33:51 (h:m:s)
Declination +30:39:36.7 (deg:m:s)
Distance 3000 (kly)
Visual Brightness B=6.26, V=5.7 (mag)
Apparent Dimension 66' x 40' (arc min)

Optic(s): RC 12" with Astro-Physics corrector @ f/5
Mount: ASA DDM85 Premium
Camera: ATIK 4000 - monochrome CCD – 2048 x 2048 px ; 16x16 mm; 7.4 µm x 7.4 µm
Filters: Astronomik HaLRGB set, SupaSlim TrueTechnology Computerized Filter Wheel
Dates/Times: 2012-11-03, 2012-11-04, 2012-11-12 (three different nights)
Location: IRIDA Observatory, BG, longitude: E 24 44' 18", latitude: N 41 41' 42"
Exposure Details:

Ha = 100 min (subs. 20 min, bin 1) L = 70 min, R = 70 min, , G = 70 min, , B = 70 min (subs. 10 min, bin 1) Total Exposure Time - 380 min

More details: Dark and flat frames reduction
Guiding: All subexposures are unguided thanks to ASA DDM85 Premium mount

PixInsight / PS


All Contents copyright Velimir Popov unless otherwise noted.