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28-466: The LMC is classified as a Magellanic spiral . 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. The LMC is predicted to merge with the Milky Way in approximately 2.4 billion years. With

56-697: 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 . Both the Large and Small Magellanic Clouds have been easily visible for southern nighttime observers well back into prehistory. It has been claimed that

84-584: A cosmological constant. In honor of this work, he was awarded the AURA Science Achievement Award in 1999. Schommer also worked on clusters of galaxies and their use in establishing the extragalactic distance scale ; dark matter in dwarf galaxies ; and designed and built a Fabry–Pérot interferometer and oversaw its installation at the Cerro-Tololo Observatory. In his final year at CTIO, Schommer took over

112-550: A paper on what is now called the "short distance" to the LMC. His work on star clusters in the Magellanic Clouds and the galaxy M33 were fundamental in providing a basis for our understanding of the chemical histories of those galaxies. Schommer was an active member of the High-z Supernova Search Team and co-authored their 1998 paper arguing that we live in an accelerating universe with

140-477: A relationship between their absolute luminosity and the period over which their brightness varies. However the variable of metallicity may also need to be taken as a component of this as consensus is this likely affects their period-luminosity relations . Unfortunately, those in the Milky Way typically used to calibrate the relation are more metal-rich than those found in the LMC. Modern 8-meter-class optical telescopes have discovered eclipsing binaries throughout

168-496: A rotation period of 250 million years. The LMC was long considered to be a planar galaxy that could be assumed to lie at a single distance from the Solar System. However, in 1986, Caldwell and Coulson found that field Cepheid variables in the northeast lie closer to the Milky Way than those in the southwest. From 2001 to 2002 this inclined geometry was confirmed by the same means, by core helium-burning red clump stars, and by

196-457: A type of unbarred spiral galaxy , while SBm are a type of barred spiral galaxy . SABm are a type of intermediate spiral galaxy . Type Sm and Im galaxies have also been categorized as irregular galaxies with some structure (type Irr-1 ). Sm galaxies are typically disrupted and asymmetric. dSm galaxies are dwarf spiral galaxies or dwarf irregular galaxies , depending on categorization scheme. The Magellanic spiral classification

224-485: Is 4 × 10  ergs /s. An X-ray astronomy instrument was carried aboard a Thor missile launched from the same atoll on September 24, 1970, at 12:54 UTC and altitudes above 300 km (190 mi), to search for the Small Magellanic Cloud and to extend observation of the LMC. The source in the LMC appeared extended and contained star ε Dor . The X-ray luminosity (L x ) over the range 1.5–12 keV

252-626: Is associated with SNR 0538-69.1. SNR 0540-697 was resolved using ROSAT . Magellanic spiral A Magellanic spiral galaxy is a spiral galaxy with only one spiral arm . Magellanic spiral galaxies are classified as the type Sm (with sub-categories SAm , SBm , SABm ); the prototype galaxy and namesake for Magellanic spirals is the Large Magellanic Cloud , an SBm galaxy. They are usually smaller dwarf galaxies and can be considered to be intermediate between dwarf spiral galaxies and irregular galaxies . SAm galaxies are

280-748: Is currently undergoing vigorous star formation activity. It holds the Tarantula Nebula , the most active star-forming region in the Local Group. The LMC has a wide range of galactic objects and phenomena that make it known as an "astronomical treasure-house, a great celestial laboratory for the study of the growth and evolution of the stars", per Robert Burnham Jr. Surveys of the galaxy have found roughly 60 globular clusters , 400 planetary nebulae and 700 open clusters , along with hundreds of thousands of giant and supergiant stars. Supernova 1987A —the nearest supernova in recent years—was in

308-465: Is the one that is a bright low-mass X-ray binary system ( LMXB ) in the LMC. DEM L316 in the Cloud consists of two supernova remnants. Chandra X-ray spectra show that the hot gas shell on the upper left has an abundance of iron. This implies that the upper-left SNR is the product of a Type Ia supernova ; much lower such abundance in the lower remnant belies a Type II supernova . A 16 ms X-ray pulsar

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336-971: The Cerro Tololo Inter-American Observatory (CTIO) in Chile . He was known for his wide range of research interests, from stellar populations to cosmology . Schommer was born in Chicago, Illinois to Harvey and Bea Schommer. He received a B.A. in Physics from the University of Chicago in 1970 and a Ph.D. in Astronomy from the University of Washington in 1977, where he continued for one year as instructor. Following two years in seminary college in Chicago, he held postdoctoral positions at Caltech (as Chaim Weizmann Fellow),

364-653: The European Southern Observatory's Very Large Telescope in Chile . Astronomers claim its gravity is influenced by a nearby star, which is about five times the mass of the Sun. The Large Magellanic Cloud has a prominent central bar and spiral arm . The central bar seems to be warped so that the east and west ends are nearer the Milky Way than the middle. In 2014, measurements from the Hubble Space Telescope made it possible to determine

392-750: The Hale Observatories , the University of Chicago , and Cambridge University (as NATO Postdoctoral Fellow) before joining the Department of Physics at the State University of New Jersey. He became increasingly unhappy with the department's unwillingness to support astronomy, and in 1990 he moved to CTIO in Chile where he remained until his death in 2001. Schommer carried out some of the first charge-coupled device (CCD) imaging studies of Large Magellanic Cloud star clusters, published in

420-835: The Local Group . Parameters of these systems can be measured without mass or compositional assumptions. The light echoes of supernova 1987A are also geometric measurements, without any stellar models or assumptions. In 2006, the Cepheid absolute luminosity was re-calibrated using Cepheid variables in the galaxy Messier 106 that cover a range of metallicities. Using this improved calibration, they find an absolute distance modulus of ( m − M ) 0 = 18.41 {\displaystyle (m-M)_{0}=18.41} , or 48 kpc (160,000 light-years). This distance has been confirmed by other authors. By cross-correlating different measurement methods, one can bound

448-439: The LMC's cluster system has kinematics consistent with the clusters moving in a disk-like distribution. These results were confirmed by Grocholski et al., who calculated distances to a sample of clusters and showed that the cluster system is distributed in the same plane as the field stars. Distance to the LMC has been calculated using standard candles ; Cepheid variables are one of the most popular. These have been shown to have

476-676: The Large Magellanic Cloud. The Lionel-Murphy SNR (N86) nitrogen -abundant supernova remnant was named by astronomers at the Australian National University 's Mount Stromlo Observatory , acknowledging Australian High Court Justice Lionel Murphy 's interest in science and its perceived resemblance to his large nose. A bridge of gas connects the Small Magellanic Cloud (SMC) with the LMC, which evinces tidal interaction between

504-658: The cloud is also visible much of the night, and the height of winter in June nearly coincides with closest proximity to the Sun's apparent position. Measurements with the Hubble Space Telescope , announced in 2006, suggest the Large and Small Magellanic Clouds may be moving too quickly to be orbiting the Milky Way . Astronomers discovered a new black hole inside the Large Magellanic Cloud in November 2021 using

532-466: The current epoch at opposition on about 5 December when thus visible from sunset to sunrise from equatorial points such as Ecuador, the Congos, Uganda, Kenya and Indonesia and for part of the night in nearby months. Above about 28° south , such as most of Australia and South Africa, the galaxy is always sufficiently above the horizon to be considered properly circumpolar , thus during spring and autumn

560-474: The distance; the residual errors are now less than the estimated size parameters of the LMC. The results of a study using late-type eclipsing binaries to determine the distance more accurately was published in the scientific journal Nature in March 2013. A distance of 49.97 kpc (163,000 light-years) with an accuracy of 2.2% was obtained. Like many irregular galaxies , the LMC is rich in gas and dust, and

588-591: The first known written mention of the Large Magellanic Cloud was by the Persian astronomer ' Abd al-Rahman al-Sufi Shirazi (later known in Europe as "Azophi"), which he referred to as Al Bakr , the White Ox, in his Book of Fixed Stars around 964 AD. However, this seems to be a misunderstanding of a reference to some stars south of Canopus which he admits he has not seen. The first confirmed recorded observation

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616-549: The galaxies. The Magellanic Clouds have a common envelope of neutral hydrogen, indicating that they have been gravitationally bound for a long time. This bridge of gas is a star-forming site. No X-rays above background were detected from either cloud during the September 20, 1966, Nike-Tomahawk rocket flight nor that of two days later. The second took off from Johnston Atoll at 17:13 UTC and reached an apogee of 160 km (99 mi), with spin-stabilization at 5.6 rps. The LMC

644-499: The management of the U.S. Gemini Project Office as Project Scientist. He was an advocate for a strong national observatory that would allow U.S. astronomers access to world-class, ground-based facilities. At the time of his death, Schommer was in the process of moving to Tucson, Arizona to establish a U.S. Gemini Science Center and a remote observing facility. Schommer committed suicide in La Serena, Chile, on December 12, 2001. He

672-484: The tip of the red giant branch. All three papers find an inclination of ~ 35°, where a face-on galaxy has an inclination of 0°. Further work on the structure of the LMC using the kinematics of carbon stars showed that the LMC's disk is both thick and flared, likely due to interactions with the SMC. Regarding the distribution of star clusters in the LMC, Schommer et al. measured velocities for ~ 80 clusters and found that

700-487: Was 6 × 10  W ( 6 × 10 erg/s ). The Large Magellanic Cloud (LMC) appears in the constellations Mensa and Dorado . LMC X-1 (the first X-ray source in the LMC) is at RA 05 40 05 Dec −69° 45′ 51″, and is a high-mass X-ray binary (star system) source ( HMXB ). Of the first five luminous LMC X-ray binaries: LMC X-1, X-2, X-3, X-4 and A 0538–66 (detected by Ariel 5 at A 0538–66), LMC X-2

728-495: Was in 1503–1504 by Amerigo Vespucci in a letter about his third voyage. He mentioned "three Canopes [ sic ], two bright and one obscure"; "bright" refers to the two Magellanic Clouds , and "obscure" refers to the Coalsack . Ferdinand Magellan sighted the LMC on his voyage in 1519 and his writings brought it into common Western knowledge. The galaxy now bears his name. The galaxy and southern end of Dorado are in

756-538: Was introduced by Gerard de Vaucouleurs , along with Magellanic irregular (Im), when he revamped the Hubble classification of galaxies. Robert Schommer Robert A. Schommer (December 9, 1946 – December 12, 2001) was an American observational astronomer . He was a professor at Rutgers University and later a project scientist for the U.S. office of the Gemini Observatory Project at

784-511: Was not detected in the X-ray range 8–80 keV. Another was launched from same atoll at 11:32 UTC on October 29, 1968, to scan the LMC for X-rays. The first discrete X-ray source in Dorado was at RA 05 20 Dec −69°, and it was the Large Magellanic Cloud. This X-ray source extended over about 12° and is consistent with the Cloud. Its emission rate between 1.5–10.5 keV for a distance of 50 kpc

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