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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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 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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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...
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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...
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Stephen Shectman blends his celestial interests with his gift of developing novel telescope instrumentation. He investigates the large-scale structure of the galaxy distribution; searches for ancient stars that have few elements; develops astronomical instruments; and constructs large telescopes....
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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--A team of astronomers has discovered the most distant cluster of red galaxies ever observed using FourStar, a new and powerful near-infrared camera on the 6.5m Magellan Baade Telescope...
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The Sloan Digital Sky Survey’s fifth generation collected its very first observations of the cosmos at 1:47 a.m. on October 24, 2020. This groundbreaking all-sky survey will bolster our...
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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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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 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. 

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

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 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

Staff member emeritus François Schweizer studies galaxy assembly and evolution by observing nearby galaxies, particularly how collisions and mergers affect their properties. His research has added to the awareness that these events are dominant processes in shaping galaxies and determining their stellar and gaseous contents.

When nearby galaxies collide and merge they yield valuable clues about processes that occurred much more frequently in the younger, distant universe. When two gas-rich galaxies collide, their pervasive interstellar gas gets compressed, clumps into dense clouds, and fuels the sudden birth of billions of new stars and thousands of star clusters.

Anthony Piro is the George Ellery Hale Distinguished Scholar in Theoretical Astrophysics at the Carnegie Observatories. He is a theoretical astrophysicist studying compact objects, astrophysical explosions, accretion flows, and stellar dynamics. His expertise is in nuclear physics, thermodynamics, condensed matter physics, General Relativity, and fluid and magneto-hydrodanmics. He uses this background  to predict new observational phenomena as well as to understand the key underlying physical mechanisms responsible for current observations. He uses a combination of analytic and simple numerical models to build physical intuition for complex phenomena.

Piro recieved his 

Mark Phillips is the Las Campanas Observatory (LCO) Director Emeritus. From 2006 to 2017 Phillips served as the Associate Director for Magellan, and from 2014 to 2017 he was the interim LCO Director. He is a world-renowned supernova expert. Most stars die quietly by cooling down and “turning off” when they have exhausted their nuclear fuel. But, a few stars end in a gigantic thermonuclear explosion known as a supernova. These objects remain extremely bright for a few weeks, sometimes outshining the galaxies in which they reside. Their extreme brightness at maximum makes them potentially powerful “standard candles”—baselines for probing

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-