Astronomy Stories
Carnegie’s Mark Seibert, Barry Madore, Jeff Rich, and team have discovered that what was believed since the 1960s to be a relatively boring, small elliptical galaxy ...
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Pasadena, CA—Astronomers have believed since the 1960s that a galaxy dubbed UGC 1382 was a relatively boring, small elliptical galaxy. Ellipticals are the most common type of galaxy and lack...
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Pasadena, CA— The Astronomical Society of the Pacific (ASP) has announced that the Carnegie Observatories’ postdoctoral associate Rachael Beaton will receive the 2016 Robert J. Trumpler...
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Washington, DC— Brown dwarfs are sometimes called failed stars. They’re stars’ dim, low-mass siblings and they fade in brightness over time. They’re fascinating to astronomers...
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Pasadena, CA— Carnegie’s Allan Sandage, who died in 2010, was a tremendously influential figure in the field of astronomy. His final paper, published posthumously, focuses on unraveling a...
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Pasadena, CA— You can never predict what treasure might be hiding in your own basement. We didn’t know it a year ago, but it turns out that a 1917 image on an astronomical glass plate...
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Pasadena, CA—The lightest few elements in the periodic table formed minutes after the Big Bang.  Heavier chemical elements are created by stars, either from nuclear fusion in their...
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Take a tour with Cynthia Hunt through eight foundational images from the Carnegie Observatories' plate collection in Nautilus magazine....
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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...
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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-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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Rebecca Bernstein combines observational astronomy with developing new instruments and techniques to study her objects of interest. She focuses on formation and evolution of galaxies by studying the chemistry of objects called extra galactic globular clusters—old, spherical compact groups of...
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Josh Simon uses observations of nearby galaxies to study problems related to dark matter, chemical evolution, star formation, and the process of galaxy evolution. In one area he looks at peculiarly dark galaxies. Interestingly, some galaxies are so dark they glow with the light of just a few...
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Some 40 thousand tons of extraterrestrial material fall on Earth every year. This cosmic debris provides cosmochemist Conel Alexander with information about the formation of the Solar System, our galaxy, and perhaps the origin of life. Alexander studies meteorites to determine what went on before...
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Pasadena, CA— The Astronomical Society of the Pacific (ASP) has announced that the Carnegie Observatories’ postdoctoral associate Rachael Beaton will receive the 2016 Robert J. Trumpler Award. In...
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Pasadena, CA—Type II supernovae are formed when massive stars collapse, initiating giant explosions. It is thought that stars emit a burst of mass as a precursor to the supernova explosion. If...
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Pasadena, CA— Blazars are the brightest of active galactic nuclei, and many emit very high-energy gamma rays. New observations of a blazar known as PKS 1424+240 show that it is the most-distant known...
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October 11, 2018

Pasadena, CA—Carnegie’s Anthony Piro was part of a Caltech-led team of astronomers who observed the peculiar death of a massive star that exploded in a surprisingly faint and rapidly fading supernova, possibly creating a compact neutron star binary system. Piro’s theoretical work provided crucial context for the discovery. Their findings are published by Science.

Observations made by the Caltech team—including lead author Kishalay De and project principal investigator Mansi Kasliwal (herself a former-Carnegie postdoc)—suggest that the dying star had an unseen companion, which gravitationally siphoned away most of the star's mass before it exploded

John Graham
September 24, 2018

Washington, DC—Carnegie astronomer John Graham—who also served during different periods as both Vice President and Secretary of the American Astronomical Society—died at home in Washington, D.C., September 13 after a battle with brain cancer. He was 79.

Graham, who specialized in the observation of young stars and the star formation process in the Milky Way and neighboring galaxies, joined Carnegie’s Department of Terrestrial Magnetism from the Cerro Tololo Inter-American Observatory in 1985. George Preston, who was Director of the Carnegie Observatories at the time Graham came to DTM, also offered Graham a simultaneous five-year adjunct appointment at the

August 9, 2018

Washington, D.C.—Observatories NASA Hubble Postdoctoral Fellow Maria Drout will receive the tenth Postdoctoral Innovation and Excellence Award (PIE). These awards are made through nominations from the departments and are chosen by the Office of the President. The recipients are awarded a cash prize for their exceptionally creative approaches to science, strong mentoring, and contributing to the sense of campus community.

Maria Drout was one of four Carnegie astronomers who, along with colleagues from UC Santa Cruz, provided the first-ever glimpse of two neutron stars colliding last August. She was first author on a Science paper, which measured the changing light from that

August 2, 2018

Pasadena, CA—What happens when a star behaves like it exploded, but it’s still there?

About 170 years ago, astronomers witnessed a major outburst by Eta Carinae, the brightest known star in our Milky Way galaxy. The blast unleashed almost as much energy as a standard supernova explosion.

Yet, Eta Carinae survived.

An explanation for the eruption has eluded astrophysicists, but Carnegie telescopes played an important role in solving the mystery.

Researchers can’t t a time machine back to the mid-1800s to observe the outburst with modern technology. However, astronomers can use nature’s own “time machine,” courtesy of the fact

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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 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

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 2021.

The GMT has a unique design that offers several advantages. It is a segmented mirror telescope that employs seven of today’s largest stiff monolith mirrors as segments. Six off-axis 8.4 meter or 27-foot segments surround a central on-axis segment, forming a single optical surface 24.5 meters, or 80 feet, in diameter with a total collecting area of 368 square meters. The GMT

We are all made of stardust. Almost all of the chemical elements were produced by nuclear reactions in the interiors of stars. When a star dies a fraction of the elements is released into the inter-stellar gas clouds, out of which successive generations of stars form.

 Astronomers have a basic understanding of this chemical enrichment cycle, but chemical evolution and nulceosynthesis are still not fully understood. Andrew McWilliam measures the detailed chemical composition of Red Giant stars, which are about as old as the galaxy and retain their original chemical composition.  He is seeking answer to questions such as: What are the sites of nucleosynthesis? What

Distant galaxies offer a glimpse of the universe as it was billions of years ago. Understanding how the Milky Way and other galaxies originated provides a unique perspective on the fundamental physics of cosmology, the invisible dark matter, and  repulsive force of dark energy. Patrick McCarthy uses the facilities at Carnegie’s Las Campanas Observatory to explore the early formation and evolution of galaxies. He is also director of the Giant Magellan Telescope Organization, an international consortium that is building the next generation giant telescope.  

Galaxy formation is driven by the interplay between the large-scale distribution of dark matter—that non

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 simulations and analytic theory to figure out how the tiny fluctuations in density that were present when the universe was only 300 thousand years old, become the galaxies and black holes that we see now, after 14 billion years of cosmic evolution. 

 She has a three-pronged approach to unravelling the mysteries of the universe. On the largest scales, she studies the intergalactic

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