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The Carnegie Institution for Science is consolidating our California research departments into an expanded presence in Pasadena. With this move, we are building on our existing relationship with...
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 Illustration of DS Tuc AB by M. Weiss, CfA.
Pasadena, CA— A new kind of astronomical observation helped reveal the possible evolutionary history of a baby Neptune-like exoplanet. To study a very young planet called DS Tuc Ab, a Harvard...
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John Mulchaey
Pasadena, CA—John Mulchaey, Director and Crawford H. Greenewalt Chair of the Carnegie Observatories, was presented with a Humanitarian STAR Award by the honor...
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Washington, DC— Carnegie astronomers Stephen Shectman and Alycia Weinberger were selected for the inaugural class of Fellows of the American Astronomical Society in recognition of their “...
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Vera Rubin, courtesy of the Carnegie Institution for Science
Washington, DC— The Large Synoptic Survey Telescope and its joint funding agencies, the National Science Foundation and Department of Energy, announced Monday that it will be renamed the Vera C...
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Illustration by James Josephides, courtesy of Swinburne Astronomy Productions.
Pasadena, CA—A star traveling at ultrafast speeds after being ejected by the supermassive black hole at the heart of our galaxy was spotted by an international team of astronomers including...
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Ancient gas cloud courtesy of the Max Planck Society.
Washington, DC— The discovery of a 13 billion-year-old cosmic cloud of gas enabled a team of Carnegie astronomers to perform the earliest-ever measurement of how the universe was enriched with...
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The Earthbound Planet Search Program has discovered hundreds of planets orbiting nearby stars using telescopes at Lick Observatory, Keck Observatory, the Anglo-Australian Observatory, Carnegie's Las Campanas Observatory, and the ESO Paranal Observatory.  Our multi-national team has been...
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The Giant Magellan Telescope will be one member of the next class of super giant earth-based telescopes that promises to revolutionize our view and understanding of the universe. It will be constructed in the Las Campanas Observatory in Chile. Commissioning of the telescope is scheduled to begin in...
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The Carnegie-Spitzer-IMACS (CSI) survey, currently underway at the Magellan-Baade 6.5m telescope in Chile, has been specifically designed to characterize normal galaxies and their environments at a distance of about 4 billion years post Big Bang, expresses by astronomers as  z=1.5. The survey...
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With the proliferation of discoveries of planets orbiting other stars, the race is on to find habitable worlds akin to the Earth. At present, however, extrasolar planets less massive than Saturn cannot be reliably detected. Astrophysicist John Chambers models the dynamics of these newly found giant...
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Juna Kollmeier’s research is an unusual combination—she is as observationally-oriented theorist making predictions that can be compared to current and future observations. Her primary focus is on the emergence of structure in the universe. She combines cosmological hydrodynamic...
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Gwen Rudie
Gwen Rudie studies the chemical and physical properties of very distant galaxies and their surrounding gas in order to further our understanding of the processes that are central to the formation and development of galaxies. Critical to this research is our ability to trace the raw...
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Two nights ago, for the first time in history, astronomers from University of Arizona and Carnegie's Yuri Beletsky at Las Campanas Observatory used the Clay Magellan telescope together with...
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It is commonly believed that when looking for valuable treasure, the best place to look is the attic—after all, works by Caravaggio, Van Gogh, Rembrandt, and Jackson Pollack have been...
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Former Carnegie fellow and current trustee, astronomer Sandra Faber, has been awarded the 2017 Gruber Foundation Cosmology Prize.
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This artist's impression of the quasar P172+18. Credit: ESO/M. Kornmesser.
March 8, 2021

Pasadena, CA— The Magellan Baade telescope at Carnegie’s Las Campanas Observatory played an important role in the discovery of the most-distant known quasar with a bright radio emission, which was announced by a Max Planck Institute for Astronomy in Heidelberg and European Southern Observatory-led team and published in The Astrophysical Journal. One of the fastest-growing supermassive black holes ever observed, it is emitting about 580 times the energy as the entire Milky Way galaxy.

Quasars are incredibly luminous supermassive black holes accreting matter at the centers of massive galaxies. Their brightness allows astronomers to study them in detail even at great

3D spatial distribution of 16 spectroscopically confirmed proto-clusters.
February 12, 2021

Las Campanas Observatory—When the universe was about 350 million years old it was dark: there were no stars or galaxies, only neutral gas—mainly hydrogen—the residue of the Big Bang. That foggy period began to clear as atoms clumped together to form the first stars and the first quasars, causing the gas to ionize and high-energy photons to travel freely through space. 

This epoch, called the “reionization” epoch, lasted about 370 million years and the first large structures in the universe appear as groups or clusters of galaxies. 

An international team of astronomers grouped in the LAGER consortium (Lyman Alpha Galaxies in the Epoch

Vicinity of Tucana II ultra-faint dwarf galaxy. Credit: Anirudh Chiti/MIT.
February 1, 2021

Pasadena, CA—An MIT-led team of astronomers that includes Carnegie’s Joshua Simon, Lina Necib, and Alexander Ji has discovered an unexpected outer suburb of stars on the distant fringes of the dwarf galaxy Tucana II. Their detection, published by Nature Astronomy, confirms that the cosmos’ oldest galaxies formed inside massive clumps of dark matter—what astronomers refer to as a “dark matter halo."

Our own Milky Way is surrounded by a cadre of orbiting dwarf galaxies—relics of the ancient universe. A new technique developed by lead author Anirudh Chiti of MIT extended the astronomers’ reach and revealed never-before-seen stars on the

A giant star being slowly devoured by a black hole courtesy of NASA Goddard.
January 12, 2021

Pasadena, CA—In a case of cosmic mistaken identity, an international team of astronomers revealed that what they once thought was a supernova is actually periodic flaring from a galaxy where a supermassive black hole gives off bursts of energy every 114 days as it tears off chunks of an orbiting star.

Six years after its initial discovery—reported in The Astronomer’s Telegram by Carnegie’s Thomas Holoien—the researchers, led by Anna Payne of University of Hawai’i at Mānoa, can now say that the phenomenon they observed, called ASASSN-14ko, is a periodically recurring flare from the center of a galaxy more than 570 million light-years away in the

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The Carnegie Hubble program is an ongoing comprehensive effort that has a goal of determining the Hubble constant, the expansion rate of the universe,  to a systematic accuracy of 2%. As part of this program, astronomers are obtaining data at the 3.6 micron wavelength using the Infrared Array Camera (IRAC) on Spitzer Space Telescope. The team has demonstrated that the mid-infrared period-luminosity relation for Cepheids, variable stars used to determine distances and the rate of the expansion,  at 3.6 microns is the most accurate means of measuring Cepheid distances to date. At 3.6 microns, it is possible to minimize the known remaining systematic uncertainties in the Cepheid

The recent discovery that the universe is expanding at an accelerating rate has profoundly affected physics. If the universe were gravity-dominated then it should be decelerating. These contrary results suggest a new form of “dark energy”—some kind of repulsive force—is driving the universe. To get a grasp of dark energy, it is extremely important that scientists get the most accurate measurements possible of Type Ia supernovae. These are specific types of exploring stars with exceptional luminosity that allow astronomers to determine distances and the acceleration rate at different distances. At the moment, the reality of the accelerating universe remains

The Carnegie-Spitzer-IMACS (CSI) survey, currently underway at the Magellan-Baade 6.5m telescope in Chile, has been specifically designed to characterize normal galaxies and their environments at a distance of about 4 billion years post Big Bang, expresses by astronomers as  z=1.5.

The survey selection is done using the Spitzer Space Telescope Legacy fields, which provides as close a selection by stellar mass as possible.

Using the IMACS infrared camera, the survey goal is to study galaxies down to low light magnitudes. The goal is to reduce the variance in the density of massive galaxies at these distances and times to accurately trace the evolution of the galaxy mass

Along with Alycia Weinberger and Ian Thompson, Alan Boss has been running the Carnegie Astrometric Planet Search (CAPS) program, which searches for extrasolar planets by the astrometric method, where the planet's presence is detected indirectly through the wobble of the host star around the center of mass of the system. With over eight years of CAPSCam data, they are beginning to see likely true astrometric wobbles beginning to appear. The CAPSCam planet search effort is on the verge of yielding a harvest of astrometrically discovered planets, as well as accurate parallactic distances to many young stars and M dwarfs. For more see  http://instrumentation.obs.carnegiescience.edu/

While the planets in our Solar System are astonishingly diverse, all of them move around the Sun in approximately the same orbital plane, in the same direction, and primarily in circular orbits. Over the past 25 years Butler's work has focused on improving the measurement precision of stellar Doppler velocities, from 300 meters per second in the 1980s to 1 meter a second in the 2010s to detect planets around other stars. The ultimate goal is to find planets that resemble the Earth.

Butler designed and built the iodine absorption cell system at Lick Observatory, which resulted in the discovery of 5 of the first 6 known extrasolar planets.  This instrument has become the de

Alan Boss is a theorist and an observational astronomer. His theoretical work focuses on the formation of binary and multiple stars, triggered collapse of the presolar cloud that eventually made  the Solar System, mixing and transport processes in protoplanetary disks, and the formation of gas giant and ice giant protoplanets. His observational works centers on the Carnegie Astrometric Planet Search project, which has been underway for the last decade at Carnegie's Las Campanas Observatory in Chile.

While fragmentation is universally recognized as the dominant formation mechanism for binary and multiple stars, there are still major questions. The most important of these

Staff astronomer emeritus Eric Persson headed a group that develops and uses telescope instrumentation to exploit new near-infrared (IR) imaging array detectors. The team built a wide-field survey camera for the du Pont 2.5-meter telescope at Carnegie’s Las Campanas Observatory in Chile, and the first of two cameras for the Magellan Baade telescope. Magellan consortium astronomers use the Baade camera for various IR-imaging projects, while his group focuses on distant galaxies and supernovae.

Until recently, it was difficult to find large numbers of galaxies at near-IR wavelengths. But significant advances in the size of IR detector arrays have allowed the Persson group

Alycia Weinberger wants to understand how planets form, so she observes young stars in our galaxy and their disks, from which planets are born. She also looks for and studies planetary systems.

Studying disks surrounding nearby stars help us determine the necessary conditions for planet formation. Young disks contain the raw materials for building planets and the ultimate architecture of planetary systems depends on how these raw materials are distributed, what the balance of different elements and ices is within the gas and dust, and how fast the disks dissipate.

Weinberger uses a variety of observational techniques and facilities, particularly ultra-high spatial-