My first time imaging Messier 33.  The temperature  Sunday night was 0 Celsius and a little windy so I shortened my run and time outside, but the time I finished I was cold and couldn’t wait to pack up and go home.  I will go for M33 again.

PinWheel Galaxy:

Pinwheel Galaxy Messier 33 (NGC 598) is commonly known as the Triangulum Galaxy. Barely visible to the naked eye, this nearby spiral is the third-largest galaxy in the Local Group, after the nearby Andromeda Galaxy (M 31) and our own Milky Way.Discovery and HistoryThe Triangulum Galaxy was probably discovered by Giovanni Batista Hodierna before 1654, who may have grouped it together with the open cluster NGC 752. The galaxy was independently rediscovered by Charles Messier in 1764, who catalogued it as M 33. The galaxy was not noted by any known pre-telescopic observer, which is not surprising: given its indistinctness, it is not likely to be noticed unless one already knows of its existence.William Herschel, who otherwise carefully avoided numbering Messier's objects, observed M 33 in 1784 and catalogued it as H V.17. Herschel also catalogued the galaxy's brightest and largest star-forming region separately as H III.150. Messier 33 was among the first "spiral Nebulae" identified by William Parsons, the Third Earl of Rosse. It was also among the first such "nebulae" identified as a separate galaxy. Edwin Hubble published a fundamental study in 1926, using Cepheid variable stars found in M 33 to show that it must lie far beyond the Milky Way.Messier 33 is sometimes informally referred to as the "Pinwheel Galaxy", a name that is more often used to refer to M 101 in Ursa Major. The Triangulum Galaxy was mentioned in the Star Trek: The Next Generation episode "Where No One Has Gone Before" as the galaxy to which the USS Enterprise travels when an apparent malfunction boosts its warp engine speed.Observing TriangulumFor the amateur observer, the Triangulum Galaxy can be glanced with the naked eye under exceptionally good conditions, making it the most distant object visible without optical aid. Its visibility is strongly affected by even small amounts of light pollution, making it one of the critical objects on the Bortle Dark Sky Scale.Visual observers may confuse M 33 with NGC 752, a nearby open cluster that is brighter than the Triangulum Galaxy. M 33 is outstanding in good binoculars, but its total magnitude of 5.7 is distributed over a 70' x 45' area - nearly four full Moons! - making its surface brightness extremely low. Therefore, low magnification is best for this object.In a modest telescope under very dark skies, one can see its loosely-wound spiral arms, filled with clumps and bright knots. The brightest of these, NGC 604 (William Herschel's H III.150), is situated in the northeastern part of the galaxy. Several other knots in the spiral arms of M 33 also have their own NGC numbers: NGCs 588, 592, 595, and NGC 603; as well as ICs 131, 132, 133, 134, 135, 136, 137, 139-40, 142, and 143.More ambitious observers with large telescopes (greater than 16" aperture) may try to track down some of M 33's globular clusters. M 33 is also a rewarding target for astrophotographers.

Properties and Associations:

At least three techniques have been used to measure M 33's distance. Older sources give 2.3 to 2.4 million light years, but a 2004 study using Cepheid variable observations found a value of 2.9 million. In 2006, the discovery of an eclipsing binary star in the Triangulum Galaxy gave a distance of 3.1 million light years. Assuming an average of 3.0 million light-years, M 33 lies about 750,000 light years from the Andromeda galaxy, M 31.At this distance, M 33's angular diameter corresponds to about 50,000 light-years - about half the size of the Milky Way. However, M 33's faintest outliers seem to reach farther, to a true diameter of perhaps 60,000 light-years. M 33 is estimated to contain 10 to 40 billion solar masses, and may be home to between 30 and 40 billion stars, compared to 200-400 billion for the Milky Way, and 1 trillion stars for Andromeda. This galaxy is small compared to the Andromeda galaxy M 31, and to our Milky Way. But this size is closer to the average known for spiral galaxies in the universe.Despite its modest size, M 33 is home to one of the largest H II regions known. NGC 604 has a diameter of nearly 1,500 light-years, and contains at least 200 newly-formed hot stars of 15 to 60 solar masses. The Triangulum galaxy is a "late" type Sc spiral, whose pronounced arms exhibit numerous reddish H II regions (including NGC 604), as well as bluish clouds of young stars. Older population II stars and globular clusters have also been found in M 33. Although no supernovae have yet been observed in the Triangulum galaxy, several supernova remnants have. At least 112 variables have been discovered in M 33, including 4 novae and about 25 Cepheids. In 2007, a black hole about 15.7 times the mass of the Sun was detected in the galaxy using data from the Chandra X-ray Observatory. The black hole, named M 33 X-7, orbits a companion star which it eclipses every 3.5 days.M 33 is approaching our Solar System at 182 km/s. Corrected for our motion around the Milky Way's galactic center, M 33 is approaching our galaxy at 24 km/sec, which means that M 33 is moving towards M 31. In fact, the Triangulum galaxy may be a remote but gravitationally bound companion of Andromeda. The Pisces Dwarf galaxy (LGS 3), one of the Local Group's small member galaxies, is possibly a satellite of Triangulum.

@SkySafari Pro