Large Magellanic Cloud
Satellite galaxy of the Milky Way / From Wikipedia, the free encyclopedia
The Large Magellanic Cloud (LMC) is a dwarf galaxy and satellite galaxy of the Milky Way.[7] At a distance of around 50 kiloparsecs (163,000 light-years),[2][8][9][10] the LMC is the second- or third-closest galaxy to the Milky Way, after the Sagittarius Dwarf Spheroidal (c. 16 kiloparsecs (52,000 light-years) away) and the possible dwarf irregular galaxy called the Canis Major Overdensity. Based on the D25 isophote at the B-band (445 nm wavelength of light), the Large Magellanic Cloud is about 9.86 kiloparsecs (32,200 light-years) across.[1][5] It is roughly one-hundredth the mass of the Milky Way[11] and is the fourth-largest galaxy in the Local Group, after the Andromeda Galaxy (M31), the Milky Way, and the Triangulum Galaxy (M33).
Large Magellanic Cloud | |
---|---|
Observation data (J2000 epoch) | |
Constellation | Dorado/Mensa |
Right ascension | 05h 23m 34s[1] |
Declination | −69° 45.4′[1] |
Distance | 163,000 light-years (49.97 kpc)[2] |
Apparent magnitude (V) | 0.13[1] |
Characteristics | |
Type | SB(s)m[1] |
Mass | 1×1010 (excluding dark matter), 1.38×1011[3] (including dark matter). M☉ |
Number of stars | 20 billion[4] |
Size | 9.86 kpc (32,200 ly)[1] (diameter; 25.0 mag/arcsec2 B-band isophote)[5] |
Apparent size (V) | 10.75° × 9.17°[1] |
Other designations | |
LMC, ESO 56- G 115, PGC 17223,[1] Nubecula Major[6] |
The LMC is classified as a Magellanic spiral.[12] It contains a stellar bar that is geometrically off-center, suggesting that it was once a barred dwarf spiral galaxy before its spiral arms were disrupted, likely by tidal interactions from the nearby Small Magellanic Cloud (SMC) and the Milky Way's gravity.[13] The LMC is predicted to merge with the Milky Way in approximately 2.4 billion years.[14]
With a declination of about −70°, the LMC is visible as a faint "cloud" from the southern hemisphere of the Earth and from as far north as 20° N. It straddles the constellations Dorado and Mensa and has an apparent length of about 10° to the naked eye, 20 times the Moon's diameter, from dark sites away from light pollution.[15]