[ad_1]
The Large Magellanic Cloud is a nearby galaxy, 1/10 the mass of the Milky Way, with a cloud-like appearance. It has 400 planetary nebulae, 60 globular clusters, and 700 open clusters. It is measured using Cepheid variable stars.
The Large Magellanic Cloud is a neighboring galaxy of the Milky Way, our home galaxy. It is only 160,000 light years away, far less than the more famous Andromeda Galaxy, which is two million light years away. The Large Magellanic Cloud receives less attention because it is less photogenic, less luminous, and significantly smaller than both the Milky Way and the Andromeda galaxies.
The Large Magellanic Cloud has a mass of about ten billion Suns, making it only 1/10 the mass of the Milky Way. The Large Magellanic Cloud is called a “cloud” because of its cloud-like appearance: it is not fundamentally different in composition than any other galaxy. Surveys of the Large Magellanic Cloud have found 400 planetary nebulae, 60 globular clusters and 700 open clusters, with hundreds of thousands of giant and supergiant stars. The most recent supernova, Supernova 1987a, occurred in the Large Magellanic Cloud. Observations of stellar phenomena within the cloud have been used for generations to familiarize astronomers with different classes of celestial objects.
The Large Magellanic Cloud is classified as an irregular galaxy, although it has a prominent bar in its center indicating it may have been a barred spiral in the past. The Large Magellanic Cloud is the second-closest galaxy to the Milky Way: only the Sagittarius Dwarf Spheroidal is closer, at a distance of only 51,000 light-years. This is very close, as the Milky Way galaxy itself is only 100,000 light-years in diameter.
As with other galaxies, the distance to the Large Magellanic Cloud is measured using what astronomers call “standard candles”, the most popular being Cepheid variable stars. Cepheid variable stars ignite and cool over broadly fixed periodic intervals. Since the period of their variability is strongly related to their absolute magnitude, the absolute magnitude of distant Cepheid variables can be known by observing their period. Once the absolute and observed magnitudes of the star are known, its distance can be calculated.
[ad_2]