Astronomy Stories
Wendy Freedman, the Crawford H. Greenewalt Director of the Carnegie Observatories and chair of the Giant Magellan Telescope Organization has accepted a position as a University Professor of Astronomy...
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Washington, D.C.—Astronomers have discovered an extremely cool object that could have a particularly diverse history—although it is now as cool as a planet, it may have spent much of its youth as hot...
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AudioPasadena, CA—Something is amiss in the Universe. There appears to be an enormous deficit of ultraviolet light in the cosmic budget. The...
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Audio Washington, D.C.— An international team of astronomers, including five Carnegie scientists, reports the discovery of two new planets...
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Pasadena, CA—Wolf-Rayet stars are very large and very hot. Astronomers have long wondered whether Wolf-Rayet stars are the progenitors of certain types of supernovae. New work from the Palomar...
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Audio Pasadena, CA— The structures and star populations of massive galaxies appear to change as they age, but much about how these...
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Pasadena, CA— New work from a team of scientists including Carnegie’s Josh Simon analyzed the chemical elements in the faintest known galaxy, called Segue 1, and determined that it is effectively a...
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Pasadena, CA— Astronomer and instrumentation expert Stephen Shectman of the Carnegie Observatories has been elected to the National Academy of Sciences. Shectman investigates the large-scale...
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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...
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The Carnegie Irvine Galaxy Survey is obtaining high-quality optical and near-infrared images of several hundred of the brightest galaxies in the southern hemisphere sky, at Carnegie’s Las Campanas Observatory to investigate the structural properties of galaxies. For more see    http...
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The fund supports a postdoctoral fellowship in astronomy that rotates between the Carnegie Science departments of Terrestrial Magnetism in Washington, D.C., and the Observatories in Pasadena California. 
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Leopoldo Infante became the director of the Las Campanas Observatory on July 31, 2017. Since 2009, Infante has been the founder and director of the Centre for Astro-Engineering at the Chilean university. He joined PUC as an assistant professor in 1990 and has been a full professor since 2006. He...
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Nick Konidaris is a staff scientist at the Carnegie Observatories and Instrument Lead for the SDSS-V Local Volume Mapper (LVM). He works on a broad range of new optical instrumentation projects in astronomy and remote sensing. Nick's projects range from experimental to large workhorse...
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Johanna Teske became the first new staff member to join Carnegie’s newly named Earth and Planets Laboratory (EPL) in Washington, D.C., on September 1, 2020. She has been a NASA Hubble Fellow at the Carnegie Observatories in Pasadena, CA, since 2018. From 2014 to 2017 she was the Carnegie...
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Pasadena, CA— Miguel Roth, director of Carnegie’s Las Campanas Observatory in Chile from 1990 to 2014 and the current representative of the Giant Magellan Telescope Organization (GMTO) in Chile was...
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Carnegie astronomer Mark Phillips, interim director of the Las Campanas Observatory, is one of a group of scientists being honored with the Breakthrough Prize in Fundamental Physics. The prize...
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The mysterious Blue Ring Nebula has puzzled astronomers since it was discovered in 2004. New work published in Nature by a Caltech-led team including Carnegie astrophysicists Mark Seibert and Andrew...
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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 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 collecting data for 30 years, using the Precision Doppler technique.  Highlights of this program include the detection of five of the first six exoplanets, the first eccentric planet, the first multiple planet system, the first sub-Saturn mass planet, the first sub-Neptune mass planet, the first terrestrial mass planet, and the first transit planet.Over the course of 30 years we have

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

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

Johanna Teske became the first new staff member to join Carnegie’s newly named Earth and Planets Laboratory (EPL) in Washington, D.C., on September 1, 2020. She has been a NASA Hubble Fellow at the Carnegie Observatories in Pasadena, CA, since 2018. From 2014 to 2017 she was the Carnegie Origins Postdoctoral Fellow—a joint position between Carnegie’s Department of Terrestrial Magnetism (now part of EPL) and the Carnegie Observatories.

Teske is interested in the diversity in exoplanet compositions and the origins of that diversity. She uses observations to estimate exoplanet interior and atmospheric compositions, and the chemical environments of their formation

Director Emeritus, George Preston has been deciphering the chemical evolution of stars in our Milky Way for a quarter of a century. He and Steve Shectman started this quest using a special technique to conduct a needle-in-the-haystack search for the few, first-generation stars, whose chemical compositions sketch the history of element formation in the galaxy. These earliest stars are very rare and they are characteristically low in heavy metals because of their age. They were made of Big Bang material, mostly hydrogen and helium. It was only later that heavier elements were formed in the nuclear furnaces of newer stars.

 In their first study, Preston and Shectman compiled a

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

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 materials of galaxy formation and its biproducts. These clues can be found in the gas that surrounds early galaxies. She is primarily an observational astronomer, working on the analysis and interpretation of high-resolution spectroscopy of distant quasars as well as near-infrared and optical spectroscopy of high-redshift galaxies. In addition to her scientific efforts, she is also the