Astronomy Stories
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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Washington, D.C.—A team of scientists, including Carnegie’s Alan Boss, has discovered two Earth-like planets in the habitable orbit of a Sun-like star. Their work is published in Science Express.  ...
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Pasadena, CA— Supernovae were always thought to occur in two main varieties. But a team of astronomers including Carnegie’s Wendy Freedman, Mark Phillips and Eric Persson is reporting the discovery...
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Pasadena, CA — Using information gathered from several telescopes, a team of astronomers, including Carnegie’s Eric Murphy, searched the sky for very rarely seen dusty starburst galaxies, formed soon...
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Pasadena, CA—For only the second time in history, a team of scientists--including Carnegie's Michele Fumagalli--have discovered an extremely rare triple quasar system. Their work is published by...
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Pasadena, CA— A team of astronomers including Carnegie’s Ian Thompson have managed to improve the measurement of the distance to our nearest neighbor galaxy and, in the process, refine an...
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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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Washington, D.C.— An international team of scientists, including Carnegie’s Paul Butler, has discovered that Tau Ceti, one of the closest and most Sun-like stars, may have five planets. Their work is...
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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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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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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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Globular clusters are spherical systems of some 100,000  gravitationally bound stars. They are among the oldest components of our galaxy and are key to understanding the age and scale of the universe. Previous measurements of their distances have compared the characteristics of different types...
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Galacticus is not a super hero; it’s a super model used to determine the formation and evolution of the galaxies. Developed by Andrew Benson, the George Ellery Hale Distinguished Scholar in Theoretical Astrophysics, it is one of the most advanced models of galaxy formation available. Rather...
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Pasadena, CA— Supernovae were always thought to occur in two main varieties. But a team of astronomers including Carnegie’s Wendy Freedman, Mark Phillips and Eric Persson is reporting the discovery...
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Johanna Teske was awarded the third Postdoctoral Innovation and Excellence (PIE) Award, which is made through nominations from the department directors and chosen by the Office of the President. She...
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Audio Washington, D.C.— An international team of astronomers, including five Carnegie scientists, reports the discovery of two new planets orbiting a very old star that is near to our own Sun. One of...
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Earth's Moon, public domain image
January 23, 2019

Pasadena, CA— “Can moons have moons?”

This simple question—asked by the four-year old son of Carnegie’s Juna Kollmeier—started it all.  Not long after this initial bedtime query,  Kollmeier was coordinating a program at the Kavli Institute for Theoretical Physics (KITP)  on the Milky Way while her one-time college classmate Sean Raymond of Université de Bordeaux was attending a parallel KITP program on the dynamics of Earth-like planets.   After discussing this very simple question at a seminar, the two joined forces to solve it.  Their findings are the basis of a paper published in Monthly Notices

December 14, 2018

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 awarded the Bernardo O’Higgins Order by the Chilean Foreign Affairs Ministry in Santiago today. The honor is in recognition “of his contribution to the development of astronomy in Chile, and for inspiring appreciation and knowledge of astronomy among students and people of all ages.”

The award is the highest civilian honor for non-Chileans. O’Higgins was one of the founders of the Chilean Republic. The award was established in 1965 to recognize

An artist’s conception of a type Ia supernova exploding, courtesy of ESO.
December 11, 2018

Pasadena, CA—New work from the Carnegie Supernova Project provides the best-yet calibrations for using type Ia supernovae to measure cosmic distances, which has implications for our understanding of how fast the universe is expanding and the role dark energy may play in driving this process. Led by Carnegie astronomer Chris Burns, the team’s findings are published in The Astrophysical Journal.  

Type Ia supernovae are fantastically bright stellar phenomena. They are violent explosions of a white dwarf—the crystalline remnant of a star that has exhausted its nuclear fuel—which is part of a binary system with another star.

In addition to being

Pan-STARRS image showing the host galaxy of the newly discovered supernova ASASSN-18bt
November 29, 2018

Pasadena, CA—A supernova discovered by an international group of astronomers including Carnegie’s Tom Holoien and Maria Drout, and led by University of Hawaii’s Ben Shappee, provides an unprecedented look at the first moments of a violent stellar explosion. The light from the explosion's first hours showed an unexpected pattern, which Carnegie's Anthony Piro analyzed to reveal that the genesis of these phenomena is even more mysterious than previously thought.

Their findings are published in a trio of papers in The Astrophysical Journal and The Astrophysical Journal Letters. (You can read them here, here, and here.)

Type Ia supernovae are

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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

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 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

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

John Mulchaey is the director and the Crawford H. Greenewalt Chair of the Carnegie Observatories. He investigates groups and clusters of galaxies, elliptical galaxies, dark matter—the invisible material that makes up most of the universe—active galaxies and black holes. He is also a scientific editor for The Astrophysical Journal and is actively involved in public outreach and education.

Most galaxies including our own Milky Way, exist in collections known as groups, which are the most common galaxy systems and are important laboratories for studying galaxy formation and evolution. Mulchaey studies galaxy groups to understand the processes that affect most

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

Like some other Carnegie astronomers, staff associate Jeffrey Crane blends science with technology. His primary interests are instrumentation, the Milky Way and the neighboring Local Group of galaxies, in addition to extrasolar planets. In 2004, then-research associate Crane joined Steve Shectman, Ian Thompson, and the Carnegie team to design the Planet Finder Spectrograph (PFS), now installed and operational on the Magellan Clay telescope.

Radial velocities are the speeds and directions of stars moving away from or toward the Earth.  Extrasolar planet hunters use them to detect the telltale wobbles of stars that are gravitationally tugged by orbiting planets. Astronomical