Edwin Powell Hubble was an American astronomer. He played a crucial role in establishing the fields of extragalactic astronomy and observational cosmology.
Hubble's law, also known as the Hubble–Lemaître law, is the observation in physical cosmology that galaxies are moving away from Earth at speeds proportional to their distance. In other words, the farther they are, the faster they are moving away from Earth. The velocity of the galaxies has been determined by their redshift, a shift of the light they emit toward the red end of the visible spectrum. The discovery of Hubble's law is attributed to Edwin Hubble's work published in 1929.
Extragalactic astronomy is the branch of astronomy concerned with objects outside the Milky Way galaxy. In other words, it is the study of all astronomical objects which are not covered by galactic astronomy.
Messier 87 is a supergiant elliptical galaxy in the constellation Virgo that contains several trillion stars. One of the largest and most massive galaxies in the local universe, it has a large population of globular clusters—about 15,000 compared with the 150–200 orbiting the Milky Way—and a jet of energetic plasma that originates at the core and extends at least 1,500 parsecs, traveling at a relativistic speed. It is one of the brightest radio sources in the sky and a popular target for both amateur and professional astronomers.
In 1944, Walter Baade categorized groups of stars within the Milky Way into stellar populations. In the abstract of the article by Baade, he recognizes that Jan Oort originally conceived this type of classification in 1926.
Allan Rex Sandage was an American astronomer. He was Staff Member Emeritus with the Carnegie Observatories in Pasadena, California. He determined the first reasonably accurate values for the Hubble constant and the age of the universe.
The Sloan Digital Sky Survey or SDSS is a major multi-spectral imaging and spectroscopic redshift survey using a dedicated 2.5-m wide-angle optical telescope at Apache Point Observatory in New Mexico, United States. The project began in 2000 and was named after the Alfred P. Sloan Foundation, which contributed significant funding.
The Lambda-CDM, Lambda cold dark matter, or ΛCDM model is a mathematical model of the Big Bang theory with three major components:
- a cosmological constant denoted by lambda (Λ) associated with dark energy
- the postulated cold dark matter denoted by CDM
- ordinary matter
The Astronomical Observatory of Rome is one of twelve Astronomical Observatories in Italy. The main site of the Observatory is Monte Porzio Catone. Part of the Istituto Nazionale di Astrofisica since 2002.
Mario Livio is an astrophysicist and an author of works that popularize science and mathematics. For 24 years (1991–2015) he was an astrophysicist at the Space Telescope Science Institute, which operates the Hubble Space Telescope. He has published more than 400 scientific articles on topics including cosmology, supernova explosions, black holes, extrasolar planets, and the emergence of life in the universe. His book on the irrational number phi, The Golden Ratio: The Story of Phi, the World's Most Astonishing Number (2002), won the Peano Prize and the International Pythagoras Prize for popular books on mathematics.
Robert P. Kirshner is an American astronomer, Chief Program Officer for Science for the Gordon and Betty Moore Foundation, and the Clownes Research Professor of Science at Harvard University. Kirshner has worked in several areas of astronomy including the physics of supernovae, supernova remnants, the large-scale structure of the cosmos, and the use of supernovae to measure the expansion of the universe.
The known history of supernova observation goes back to 1006 AD. All earlier proposals for supernova observations are speculations with many alternatives.
Knowledge of the location of Earth has been shaped by 400 years of telescopic observations, and has expanded radically since the start of the 20th century. Initially, Earth was believed to be the center of the Universe, which consisted only of those planets visible with the naked eye and an outlying sphere of fixed stars. After the acceptance of the heliocentric model in the 17th century, observations by William Herschel and others showed that the Sun lay within a vast, disc-shaped galaxy of stars. By the 20th century, observations of spiral nebulae revealed that the Milky Way galaxy was one of billions in an expanding universe, grouped into clusters and superclusters. By the end of the 20th century, the overall structure of the visible universe was becoming clearer, with superclusters forming into a vast web of filaments and voids. Superclusters, filaments and voids are the largest coherent structures in the Universe that we can observe. At still larger scales the Universe becomes homogeneous, meaning that all its parts have on average the same density, composition and structure.
Heidi Jo Newberg is an American astrophysicist known for her work in understanding the structure of our Milky Way galaxy. Among her team's findings are that the Milky Way is cannibalizing stars from smaller galaxies and that the Milky Way is larger and has more ripples than was previously understood. She is a founding participant in the Sloan Digital Sky Survey (SDSS) and the Sloan Extension for Galactic Understanding and Exploration (SEGUE), and is a leader of the astrophysical MilkyWay@home volunteer computing project team. She is a professor in the Department of Physics, Applied Physics, and Astronomy at Rensselaer Polytechnic Institute (RPI) in Troy, New York, US, and a Fellow of the American Physical Society.
Jeremy Richard Mould is an Australian astronomer currently at the Centre for Astrophysics and Supercomputing at Swinburne University of Technology. Mould was previously Director of the Research School of Astronomy and Astrophysics at the Australian National University and the American National Optical Astronomy Observatory. He is an Honorary Professorial Fellow, at the University of Melbourne.
Wendy Laurel Freedman is a Canadian-American astronomer, best known for her measurement of the Hubble constant, and as director of the Carnegie Observatories in Pasadena, California, and Las Campanas, Chile. She is now the John & Marion Sullivan University Professor of Astronomy and Astrophysics at the University of Chicago. Her principal research interests are in observational cosmology, focusing on measuring both the current and past expansion rates of the universe, and on characterizing the nature of dark energy.
Alice Eve Shapley is a professor at the University of California, Los Angeles (UCLA) in the Department of Physics and Astronomy. She was one of the discoverers of the spiral galaxy BX442. Through her time at University of California, Los Angeles (UCLA) she has taught Nature of the Universe, Black Holes and Cosmic Catastrophes, Cosmology: Our Changing Concepts of the Universe, Galaxies, Scientific Writing, AGNs, Galaxies, *and* Writing, and The Formation and Evolution of Galaxies and the IGM. Shapley has committed herself to over a two decades of research and publication in the interest of physics and astronomy.
Warrick John Couch is an Australian professional astronomer. He is currently a professor at Swinburne University of Technology in Melbourne. He was previously the Director of Australia's largest optical observatory, the Australian Astronomical Observatory (AAO). He was also the president of the Australian Institute of Physics (2015–2017), and a non-executive director on the Board of the Giant Magellan Telescope Organization. He was a founding non-executive director of Astronomy Australia Limited.
Laura Ferrarese is a researcher in space science at the National Research Council of Canada. Her primary work has been performed using data from the Hubble Space Telescope and the Canada-France-Hawaii Telescope.
Jonathan (Joss) Bland-Hawthorn is a British-Australian astrophysicist. He is a Laureate professor of physics at the University of Sydney, and director of the Sydney Institute for Astronomy.
