Триангулум Галактикасы: Жұлдыздар мен спиральдар әлемі

Spiral galaxy in the constellation Triangulum

The galaxy gets its name from the constellation Triangulum, where it can be spotted. It is sometimes informally referred to as the "Pinwheel Galaxy" by some astronomy references, This is fainter than many people are able to see, even at a very dark site.

The Triangulum Galaxy is the third largest member of the Local Group of galaxies. It has a diameter measured through the D25 standard the isophote where the surface brightness of the galaxy reaches 25 mag/arcsec2, to be about , making it roughly 70% the size of the Milky Way. It may be a gravitationally bound companion of the Andromeda Galaxy. Triangulum may be home to 40 billion stars, compared to 400 billion for the Milky Way and 1 trillion for Andromeda. In 2006, a group of astronomers announced the discovery of an eclipsing binary star in the Triangulum Galaxy. By studying the eclipses of the stars, astronomers were able to measure their sizes. Knowing the sizes and temperatures of the stars, they were able to measure the absolute magnitude of the stars. When the visual and absolute magnitudes are known, the distance to the star can be measured. The stars lie at the distance of
The Triangulum Galaxy is a source of H2O maser emission. The Pisces Dwarf (LGS 3), one of the small Local Group member galaxies, is located from the Sun. It is 20° from the Andromeda Galaxy and 11° from Triangulum. As LGS 3 lies at a distance of from both galaxies, it could be a satellite galaxy of either Andromeda or Triangulum. LGS 3 has a core radius of and 2.6 × 107 solar masses.

In the French astronomer Gérard de Vaucouleurs' revised Hubble Sandage (VRHS) system of galaxy morphological classification, the Triangulum Galaxy is classified as type SA(s)cd. The S prefix indicates that it is a disk shaped galaxy with prominent arms of gas and dust that spiral out from the nucleus—what is commonly known as a spiral galaxy. The A is assigned when the galactic nucleus lacks a bar shaped structure, in contrast to SB class barred spiral galaxies. American astronomer Allan Sandage's "(s)" notation is used when the spiral arms emerge directly from the nucleus or central bar, rather than from an inner ring as with an (r) type galaxy. Finally, the cd suffix represents a stage along the spiral sequence that describes the openness of the arms. A rating of cd indicates relatively loosely wound arms. About 54 globular clusters have been identified in this galaxy, but the actual number may be 122 or more.

As mentioned above, M33 is linked to M31 by several streams of neutral hydrogen and stars, and a more violent encounter will occur 2.5 billion years in the future. or participating in the collision between the Milky Way and M31, likely ending up orbiting the merger product and fusing with it much later. Two other possibilities are a collision with the Milky Way before the Andromeda Galaxy arrives or an ejection out of the Local Group. Astrometric data from Gaia appears in 2019 to rule out the possibility that M33 and M31 are in orbit. If correct, M33 is on its first infall proper into the Andromeda Galaxy (M31).