M33 - Triangulum Galaxy
 
Date:
 
July 24, 2015
 
Location:
 
Landers, California USA
 
Telescope:
 
Explore Scientific ED127 Apo
 
Camera:
 
SBIG STF-8300M
 
Mount:
 
Astro-Physics Mach1GTO
 
Acquisition:
 
Maxim DL Pro 6
 
Filters:
 
Baader LRGB
 
Total Integration:
 
3.17 hours
 
Calibration:
 
Darks: 15ea
Bias: 15ea
Flats: 15ea
 
Subexposures:
 
L: 20 x 300s (1x1)
R: 15 x 120s (2x2)
G: 15x 120s (2x2)
B: 15 x 120s (2x2)
 
The Triangulum Galaxy is a spiral galaxy in the constellation Triangulum. It is also known as Messier 33 or NGC 598, and is sometimes referred to as the Pinwheel Galaxy, a nickname it shares with Messier 101.

With a diameter of about 60,000 light-years, the Triangulum Galaxy is the third-largest member of our Local Group of galaxies. The Local Group is a cluster of galaxies which includes the Milky Way Galaxy, Andromeda Galaxy and about 44 other galaxies. The Triangulum Galaxy is estimated to hold 40 billion stars, compared to 400 billion for the Milky Way and 1 trillion for the Andromeda Galaxy.

At a distance of 3 million light-years away, It is one of the most distant astronomical objects that can be viewed with the naked eye. Viewing it without the aid of a telescope requires exceptionally clear skies with no light pollution. It ranges from easily visible in dark skies to a difficult averted vision object in rural or suburban skies. For this reason, the Triangulum Galaxy is one of the critical sky marks of the Bortle Dark-Sky Scale.

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.