Skies By Africa

Images of the Heavens By Eric Africa

M33, the Triangulum Galaxy

M33 is one of the spectacular deep sky objects visible during fall (for the Northern Hemisphere). From our perspective, it lies in the constellation Triangulum, near Andromeda. For this reason it is known as the Triangulum galaxy, though it is also called the Pinwheel Galaxy (along with M101).

Despite its relative proximity to our galaxy and large size from our perspective, M33 is hard to see from a light-polluted site because it is dim for its size. It is classified by some as a low-surface-brightness galaxy for this reason.

Part of the reason for M33's low-surface brightness is its lack of a bright core region, as is typical of most spiral galaxies. It has recently been determined to lack a black hole in its nucleus, which may explain its loose nature as well as its low surface brightness.

M33 is known to be interacting with M31, and may eventually merge with its larger neighbor. M31 has recently been determined to have two black holes in its core, and observations have also indicated that M33 had a close encounter with M31 in the past. Now, wouldn't it be neat if we ever determine that the second black hole at M31's core actually used to reside at M33's core?

M33 is best seen from a dark sky site. My first definite sighting of this galaxy was at a very dark site in New Mexico through a 25" reflector in 2008, though high thin clouds at the time prevented me from seeing it at its best.
Constellation: Triangulum
When Visible: September - January
Distance: 3 Million Light-years
Date: August - September, 2008
Location: West Chester, Ohio
Exposure Details:
L: 43 x 10 minutes binned 1x1
R: 15 x 15 minutes binned 1x1
G: 15 x 15 minutes binned 1x1
B: 15 x 15 minutes binned 1x1
Equipment Used: Takahashi FSQ-106N on an Astro-Physics AP1200GTO mount. SBIG ST-10XMEI camera with CFW-8a filter wheel and Astrodon LRGB filters and Hutech LPS filter. Externally guided with a Meade DSI Pro on a Borg 45ED refractor.
Acquisition Software : MaximDL, TheSky6, CCDAutopilot
Processing Software: MaximDL, Photoshop CS, IrFanView
Older version: 2004 Version. Takahashi FS-102 on a Takahashi EM200 Temma-2 Mount. SBIG ST-8XE with Custom-Scientific LRGB Filters.