Triangulum Galaxy
The Triangulum Galaxy, more accurate than Triangulum Galaxy (also known as Triangulumnebel, Messier 33 and NGC 598 referred ) is a spiral galaxy with dimensions of 70 ' x 40 ' and the overall brightness of 5.7 mag in the constellation triangle. Thus, it is after the Andromeda Galaxy, the second brightest spiral galaxy in the night sky and one of our closest.
However, its brightness spread over a larger area so that they do not freiäugig, but at best in binoculars is visible. Therefore are easier to observe in the telescope about 20 distant galaxies.
Description
The Triangulum Galaxy is with a diameter of about 50,000 to 60,000 light years from the Andromeda Galaxy ( ≈ 150,000 light years ) and the Milky Way ( ≈ 100,000 light years ) the third-largest object in the Local Group.
Completely run by the M33 in the Messier catalog object was according to the second galaxy M51, at the Lord Rosse in 1845 with his giant telescope could foresee a spiral structure. The existence of these spiral arms has been doubted by other astronomers, but long.
The distance to the Triangulum Galaxy is just under 3 million light-years, the baryonic mass of the spiral galaxy (stars and gas ) is about 2% of the mass of the Milky Way or 4-6 billion solar masses. Together with the surrounding dark matter is likely to be between 20 and 40 billion solar masses.
Perhaps the Triangulum Galaxy is gravitationally bound to the Andromeda nebula, from which he is about 1 million light- years away.
Proper motion
2005 succeeded a German team of researchers from observations of H2O masers on opposite sides of the spiral galaxy with the VLBA to set up a model for the rotation and proper motion of the Triangulum galaxy. The team came to the conclusion that the galaxy itself. Having a proper motion of -30 ± 8 micro- arcseconds ( μ " / a ) per year in right ascension and 45 ± 9 μ " moves / a declination From this, the researchers involved an overall rate of 190 ± 60 km / s relative to the Milky Way system, showing the movement in the general direction of the Andromeda nebula. Such measurements have so far succeeded only for a few galaxies and provide an essential prerequisite for dynamic models of the Local Group dar.
Associated objects
There are some globular clusters, some of which are rare object class of the blue globular clusters associated with this galaxy. Probably the Triangulum Galaxy also has a satellite galaxy, namely the Pisces dwarf galaxy.
HII regions
Even William Herschel noticed in monitoring the Triangulum galaxy, the large HII region ( a diffuse gaseous nebulae of ionized hydrogen) NGC 604 Herschel took this as a separate object but still true and gave her the name H III.150. This giant star -forming region is one with a diameter of nearly 1500 light years of the largest known objects of this type and is similar to the spectral characteristics of the Orion Nebula. Even amateur telescopes allow the observation of this gas nebula, which is north-east to find the center of the galaxy. Herschel also noticed three smaller HII regions, namely NGC 588, NGC 592 and NGC 595
M33 X-7
In October of 2007, researchers discovered using the Chandra X-ray Observatory in the galaxy, the most massive black hole known at this time, which has evolved from a single star. More massive black holes are known at this time only from the nuclei of galaxies, where these objects increase in size by the collapse of matter and on. The object that was named M33 X - 7 and X-ray source is estimated to be nearly 16 solar masses. It is located in orbit around a exceptional with about 70 solar masses large star, which is likely to be a blue giant star. According to previous findings by researchers stellar black holes actually have a mass upper limit of about 15 solar masses.
Visibility
Because of its large angular extent and the resulting low surface brightness of the Triangulum Galaxy with small telescopes due to excessive enlargement is seldom to be found. It is recommended that the observation with a bright binoculars, about 15x70 or 20x80. A freiäugige sighting of the galaxy is only under very good conditions possible ( zenitnah, no moon, low light pollution ). Thus, the Triangulum Galaxy is the most distant object visible to the naked eye.