"they became an important part of the evidence that ""spiral nebulae"" are independent galaxies located far outside of our own Milky Way. Thus, Leavitt's discovery would forever change our picture of the universe, as it prompted Harlow Shapley to move our Sun from the center of the galaxy in the ""Great Debate"" and Edwin Hubble to move our galaxy from the center of the universe. Leavitt's discovery of a way to accurately measure distances on an inter-galactic scale, paved the way for modern astronomy's understanding of the structure and scale of the universe. The accomplishments of Edwin Hubble, the American"
"Edwin Hubble Edwin Powell Hubble (November 20, 1889 – September 28, 1953) was an American astronomer. He played a crucial role in establishing the fields of extragalactic astronomy and observational cosmology and is regarded as one of the most important astronomers of all time. Hubble discovered that many objects previously thought to be clouds of dust and gas and classified as ""nebulae"" were actually galaxies beyond the Milky Way. He used the strong direct relationship between a classical Cepheid variable's luminosity and pulsation period (discovered in 1908 by Henrietta Swan Leavitt) for scaling galactic and extragalactic distances. Hubble provided evidence"
"a huge number of external galaxies beyond our own Milky Way; then, work by Vesto Slipher and others showed that the universe is expanding. These advances made it possible to speculate about the origin of the universe, and allowed the establishment of the Big Bang Theory, by Georges Lemaître, as the leading cosmological model. A few researchers still advocate a handful of alternative cosmologies; however, most cosmologists agree that the Big Bang theory explains the observations better. Dramatic advances in observational cosmology since the 1990s, including the cosmic microwave background, distant supernovae and galaxy redshift surveys, have led to the"
"Galaxy, as well as the significant Doppler shift. In 1922 Ernst Öpik presented a very elegant and simple astrophysical method to estimate the distance of M31. His result put the Andromeda Nebula far outside our Galaxy at a distance of about 450,000 parsec, which is about 1,500,000 ly. Edwin Hubble settled the debate about whether other galaxies exist in 1925 when he identified extragalactic Cepheid variable stars for the first time on astronomical photos of M31. These were made using the 2.5 metre (100 in) Hooker telescope, and they enabled the distance of Great Andromeda Nebula to be determined. His"
"formation. American astronomer Edwin Hubble included M31 (then known as the Andromeda Nebula) in his groundbreaking 1923 research on galaxies. Using the 100-inch Hooker Telescope at Mount Wilson Observatory in California, he observed Cepheid variable stars in M31 during a search for novae, allowing him to determine their distance by using the stars as standard candles. The distance he found was far greater than the size of the Milky Way, which led him to the conclusion that many similar objects were ""island universes"" on their own. Hubble originally estimated that the Andromeda Galaxy was 900,000 light-years away, but Ernst Öpik's"
"Universe. To support his claim that the Great Andromeda Nebula is an external galaxy, Curtis noted the appearance of dark lanes resembling the dust clouds in the Milky Way, as well as the significant Doppler shift. In 1922, the Estonian astronomer Ernst Öpik gave a distance determination that supported the theory that the Andromeda Nebula is indeed a distant extra-galactic object. Using the new 100 inch Mt. Wilson telescope, Edwin Hubble was able to resolve the outer parts of some spiral nebulae as collections of individual stars and identified some Cepheid variables, thus allowing him to estimate the distance to"
"of the Universe about 13.8 billion years ago, and 379,000 years after the initial moments of the Big Bang. The luminous point-like cores of quasars were the first ""high-redshift"" () objects discovered before the improvement of telescopes allowed for the discovery of other high-redshift galaxies. For galaxies more distant than the Local Group and the nearby Virgo Cluster, but within a thousand megaparsecs or so, the redshift is approximately proportional to the galaxy's distance. This correlation was first observed by Edwin Hubble and has come to be known as Hubble's law. Vesto Slipher was the first to discover galactic redshifts,"
"Aleksander Wolszczan Aleksander Wolszczan (born 29 April 1946 in Szczecinek, Poland) is a Polish astronomer. He is the co-discoverer of the first extrasolar planets and pulsar planets. He was born on 29 April 1946 in Szczecinek located in present-day West Pomeranian Voivodeship, Poland; in the 1950s his family moved to Szczecin. His father Jerzy Wolszczan taught economics at former Szczecin Polytechnic (currently West Pomeranian University of Technology) and his mother, Zofia, worked for the Polish Writers' Union. His early interest in astronomy was inspired by his father who told him stories and myths connected with stellar constellations. As a seven-year-old"
"does not deserve equal credit with Le Verrier for the discovery of Neptune. That credit belongs only to the person who succeeded both in predicting the planet's place and in convincing astronomers to search for it."" Shortly after its discovery, Neptune was referred to simply as ""the planet exterior to Uranus"" or as ""Le Verrier's planet"". The first suggestion for a name came from Galle, who proposed the name ""Janus"". In England, Challis put forward the name ""Oceanus"". Claiming the right to name his discovery, Le Verrier quickly proposed the name ""Neptune"" for this new planet, though falsely stating that"
"gravitationally sculpts the morphology of the belt. Paul Kalas Paul Kalas (born August 13, 1967) is a Greek American astronomer known for his discoveries of debris disks around stars. Kalas led a team of scientists to obtain the first visible-light images of an extrasolar planet with orbital motion around the star Fomalhaut, at a distance of 25 light years from Earth. The planet is referred to as Fomalhaut b. Kalas was born in New York City to George and Maria Kavallinis, who immigrated to the United States from Heraklion, Crete. Kalas attended Detroit Country Day School in Michigan, and studied"
"life story. A famous quote by Edwin Hubble goes: ""Equipped with his five senses man explores the universe around him and calls the adventure Science"". In the popular documentary """" by astronomer Carl Sagan, Hubble's life and work are portrayed on screen in episode 10: ""The Edge of Forever."" His work on Red Shift was immortalized in a limerick by Alexander Rolfe: Edwin Hubble Edwin Powell Hubble (November 20, 1889 – September 28, 1953) was an American astronomer. He played a crucial role in establishing the fields of extragalactic astronomy and observational cosmology and is regarded as one of the"
"outside the solar system that has been directly imaged. Luhman 16 now bears the discoverer's name following common practice for very nearby stars that have been discovered in modern times. These discoveries were made through painstaking analysis of mid-infrared data from the WISE satellite, a NASA mission that mapped the entire sky and detected several hundred million stars. The satellite mapped the entire sky twice between January 2010 and January 2011, thereby providing 2 sets of images and coordinates for every star. The motions of the nearest stars over the 6 month interval between the two sets of observations were"
"of star that is used as a means to determine the distance from the galaxy – see also standard candle) in several spiral nebulae, including the Andromeda Nebula and Triangulum. His observations, made in 1922–1923, proved conclusively that these nebulae were much too distant to be part of the Milky Way and were, in fact, entire galaxies outside our own, suspected by researchers at least as early as 1755 when Immanuel Kant's General History of Nature and Theory of the Heavens appeared. This idea had been opposed by many in the astronomy establishment of the time, in particular by Harvard"
"Way galaxy to be ""a myriad of tiny stars packed together in the sphere of the fixed stars"". In the 10th century, the Persian astronomer Abd al-Rahman al-Sufi (known in the West as ""Azophi"") made the earliest recorded observation of the Andromeda Galaxy, describing it as a ""small cloud"". Al-Sufi also identified the Large Magellanic Cloud, which is visible from Yemen, though not from Isfahan; it was not seen by Europeans until Magellan's voyage in the 16th century. These were the first galaxies other than the Milky Way to be observed from Earth. Al-Sufi published his findings in his ""Book"
"Steven S. Vogt Steven Scott Vogt (born December 20, 1949) is an American astronomer of German descent whose main interest is the search for extrasolar planets. He is credited, along with R. Paul Butler, for discovering Gliese 581 g, the first potentially habitable planet outside of the Solar System. He is a professor of astronomy and astrophysics at the University of California, Santa Cruz, and is known worldwide for designing and building HIRES, a high-resolution optical spectrometer mounted permanently on the W. M. Keck Observatory 10-meter telescope on Mauna Kea, Hawaii. HIRES is an instrument critical to observations and discoveries"
"University-based Harlow Shapley. Despite the opposition, Hubble, then a thirty-five-year-old scientist, had his findings first published in ""The New York Times"" on , 1924, then presented them to other astronomers at the January 1, 1925 meeting of the American Astronomical Society. Hubble's results for Andromeda were not formally published in a peer-reviewed scientific journal until 1929. Hubble's findings fundamentally changed the scientific view of the universe. Supporters state that Hubble's discovery of nebulae outside of our galaxy helped pave the way for future astronomers. Although some of his more renowned colleagues simply scoffed at his results, Hubble ended up publishing"
"the naked eye. The discovery of celestial bodies orbiting something other than Earth dealt a serious blow to the then-accepted Ptolemaic world system, a geocentric theory in which everything orbits around Earth. Galileo initially named his discovery the Cosmica Sidera (""Cosimo's stars""), but the names that eventually prevailed were chosen by Simon Marius. Marius discovered the moons independently at the same time as Galileo, and gave them their present names, which were suggested by Johannes Kepler, in Marius's ""Mundus Jovialis"", published in 1614. As a result of improvements Galileo Galilei made to the telescope, with a magnifying capability of 20×,"
"distance determination. The extragalactic distance scale is a series of techniques used today by astronomers to determine the distance of cosmological bodies beyond our own galaxy, which are not easily obtained with traditional methods. Some procedures utilize properties of these objects, such as stars, globular clusters, nebulae, and galaxies as a whole. Other methods are based more on the statistics and probabilities of things such as entire galaxy clusters. Discovered in 1956 by Olin Wilson and M.K. Vainu Bappu, the Wilson–Bappu effect utilizes the effect known as spectroscopic parallax. Many stars have features in their spectra, such as the calcium"
"the Sun far from the center. Both analyses failed to take into account the absorption of light by interstellar dust present in the galactic plane, but after Robert Julius Trumpler quantified this effect in 1930 by studying open clusters, the present picture of our host galaxy, the Milky Way, emerged. A few galaxies outside the Milky Way are visible on a dark night to the unaided eye, including the Andromeda Galaxy, Large Magellanic Cloud and the Small Magellanic Cloud. In the 10th century, the Persian astronomer Al-Sufi made the earliest recorded identification of the Andromeda Galaxy, describing it as a"
"down. It was Isaac Newton, with his invention of celestial dynamics and his law of gravitation, who finally explained the motions of the planets. Newton also developed the reflecting telescope. Improvements in the size and quality of the telescope led to further discoveries. The English astronomer John Flamsteed catalogued over 3000 stars, More extensive star catalogues were produced by Nicolas Louis de Lacaille. The astronomer William Herschel made a detailed catalog of nebulosity and clusters, and in 1781 discovered the planet Uranus, the first new planet found. The distance to a star was announced in 1838 when the parallax of"
"fact, and indeed at the time it was highly controversial whether or not these nebulae were ""island universes"" outside our Milky Way. Ten years later, Alexander Friedmann, a Russian cosmologist and mathematician, derived the Friedmann equations from Albert Einstein's equations of general relativity, showing that the universe might be expanding in contrast to the static universe model advocated by Einstein at that time. In 1924 Edwin Hubble's measurement of the great distance to the nearest spiral nebulae showed that these systems were indeed other galaxies. Independently deriving Friedmann's equations in 1927, Georges Lemaître, a Belgian physicist, proposed that the inferred"
"of its present age. On July 11, 2007, using the 10-metre Keck II telescope on Mauna Kea, Richard Ellis of the California Institute of Technology at Pasadena and his team found six star forming galaxies about 13.2 billion light years away and therefore created when the universe was only 500 million years old. Only about 10 of these extremely early objects are currently known. More recent observations have shown these ages to be shorter than previously indicated. The most distant galaxy observed as of October 2016, GN-z11, has been reported to be 32 billion light years away, a vast distance"
"the place predicted by Lowell, and subsequent observations showed it to have an orbit beyond that of Neptune. This ruled out classification as an asteroid, and they decided this was the ninth planet that Lowell had predicted. The discovery was made on Tuesday, February 18, 1930, using images taken the previous month. The name ""Pluto"" was suggested by an 11-year-old English schoolgirl, Venetia Burney. It won out over numerous other suggestions because it was the name of the Roman god of the underworld, who was able to render himself invisible, and because Percival Lowell's initials PL formed the first 2"
"any visually diffuse astronomical object, including galaxies beyond the Milky Way, until galaxies were confirmed as extragalactic systems by Edwin Hubble in 1924.) Herschel published his discoveries as three catalogues: ""Catalogue of One Thousand New Nebulae and Clusters of Stars"" (1786), ""Catalogue of a Second Thousand New Nebulae and Clusters of Stars"" (1789) and the previously cited ""Catalogue of 500 New Nebulae ..."" (1802). He arranged his discoveries under eight ""classes"": (I) bright nebulae, (II) faint nebulae, (III) very faint nebulae, (IV) planetary nebulae, (V) very large nebulae, (VI) very compressed and rich clusters of stars, (VII) compressed clusters of"
"Carl Sagan Carl Edward Sagan (; November 9, 1934December 20, 1996) was an American astronomer, cosmologist, astrophysicist, astrobiologist, author, science popularizer, and science communicator in astronomy and other natural sciences. He is best known for his work as a science popularizer and communicator. His best known scientific contribution is research on extraterrestrial life, including experimental demonstration of the production of amino acids from basic chemicals by radiation. Sagan assembled the first physical messages sent into space: the Pioneer plaque and the Voyager Golden Record, universal messages that could potentially be understood by any extraterrestrial intelligence that might find them. Sagan"
"Nine. Following the discovery of the planet Neptune in 1846, there was considerable speculation that another planet might exist beyond its orbit. The Planet Nine hypothesis predicts a specific planet of a certain size and with certain orbital characteristics that are different from past theories. Attempts to detect planets beyond Neptune by indirect means such as orbital perturbation date back beyond the discovery of Pluto. George Forbes was the first to postulate the existence of trans-Neptunian planets in 1880, and his work is considered similar to more recent Planet Nine theories. In Forbes's model the planet had a semi-major axis"
"the outer Solar System. Although most astronomers agree that Planet X, as Lowell defined it, does not exist, as of January 2016 there is speculation concerning Planet Nine. Planets beyond Neptune Robert Sutton Harrington Robert Sutton Harrington (October 21, 1942 – January 23, 1993) was an American astronomer who worked at the United States Naval Observatory (USNO). Harrington was born near Newport News, Virginia. His father was an archaeologist. He was married to Betty-Jean Maycock in 1976, with two daughters, Amy and Ann. Harrington worked at the USNO. Another astronomer there, James W. Christy, consulted with him after discovering bulges"
"Galle, and a ring of Neptune have been named in his honor. Google celebrated Johann Gottfried Galle's 200th Birthday with Google Doodle https://www.google.com/doodles/johann-gottfried-galles-200th-birthday! Johann Gottfried Galle Johann Gottfried Galle (9 June 1812 – 10 July 1910) was a German astronomer from Radis, Germany, at the Berlin Observatory who, on 23 September 1846, with the assistance of student Heinrich Louis d'Arrest, was the first person to view the planet Neptune and know what he was looking at. Urbain Le Verrier had predicted the existence and position of Neptune, and sent the coordinates to Galle, asking him to verify. Galle found Neptune"
"Geoffrey Marcy Geoffrey William Marcy (born September 29, 1954) is an American astronomer. He is one of the pioneers and leaders in the discovery and characterization of exoplanets. Marcy was Professor of Astronomy at the University of California, Berkeley and an Adjunct Professor of Physics and Astronomy at San Francisco State University before stepping down in October 2015. His colleagues in the Berkeley Astronomy Department forced him to resign after allegations of sexual harassment were substantiated by a Berkeley investigation. Marcy and his research teams are recognized for discovering many extrasolar planets, including 70 out of the first 100 known"
"Planets beyond Neptune Following the discovery of the planet Neptune in 1846, there was considerable speculation that another planet might exist beyond its orbit. The search began in the mid-19th century and continued at the start of the 20th with Percival Lowell's quest for Planet X. Lowell proposed the Planet X hypothesis to explain apparent discrepancies in the orbits of the giant planets, particularly Uranus and Neptune, speculating that the gravity of a large unseen ninth planet could have perturbed Uranus enough to account for the irregularities. Clyde Tombaugh's discovery of Pluto in 1930 appeared to validate Lowell's hypothesis, and"
"Paul Kalas Paul Kalas (born August 13, 1967) is a Greek American astronomer known for his discoveries of debris disks around stars. Kalas led a team of scientists to obtain the first visible-light images of an extrasolar planet with orbital motion around the star Fomalhaut, at a distance of 25 light years from Earth. The planet is referred to as Fomalhaut b. Kalas was born in New York City to George and Maria Kavallinis, who immigrated to the United States from Heraklion, Crete. Kalas attended Detroit Country Day School in Michigan, and studied astronomy and physics at the University of"
"Johann Bayer gave three of these clusters designations as if they were single stars. The first person to use a telescope to observe the night sky and record his observations was the Italian scientist Galileo Galilei in 1609. When he turned the telescope toward some of the nebulous patches recorded by Ptolemy, he found they were not a single star, but groupings of many stars. For Praesepe, he found more than 40 stars. Where previously observers had noted only 6-7 stars in the Pleiades, he found almost 50. In his 1610 treatise ""Sidereus Nuncius"", Galileo Galilei wrote, ""the galaxy is"
"as astronomy textbook for secondary school. he is the author of the book essays about the universe. Boris Vorontsov-Velyaminov Boris Aleksandrovich Vorontsov-Velyaminov (Борис Александрович Воронцов-Вельяминов) (February 14, 1904 – January 27, 1994) was a Soviet/Russian astrophysicist. His name is sometimes given as Vorontsov-Vel'yaminov. He independently discovered the absorption of light by interstellar dust, which was also discovered by Robert Julius Trumpler. He compiled a catalogue of what are now known as Vorontsov-Velyaminov galaxies (the ""Atlas of Interacting Galaxies""), as well as a larger and more general catalogue of galaxies (the ""Morphological Catalogue of Galaxies""). He also studied and classified planetary"