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 distances, geometry, and expansion of the universe.

Type Ia supernovae are especially attractive. Thought to be the complete thermonuclear disruption of a small, very dense stellar remnant called a white dwarf, they are highly uniform. And because of their immense luminosity at maximum light (up to 10 billion times that of the Sun), they can be observed at great distances. Phillips wants to understand the role they have in the evolution of the universe, and to determine how they can be used as standard candles for measuring distance.

Phillips has shown that Type Ia supernovae can be used as standard candles because of a tight correlation between the rate of decline from maximum light and peak luminosity. Phillips and collaborators have extended their supernovae observations to the infrared and found that Type Ia supernovae exhibit a much smaller range of luminosities at these wavelengths, making them nearly perfect standard candles. Particularly important is that in infrared the absorption of the supernova light due to dust is negligible.

Phillip joined a two-part, 5-year project called the Carnegie Supernova Program (CSP). The team is obtaining light curves—how light varies over time—of some 100 nearby Type Ia supernovae in the optical and infrared. This sample will provide a comparison for the second component of the project—near-infrared observations of about 50 very distant—known as high-redshift (0.3 < z < 0.7) —Type Ia supernovae. The goal is to measure the expansion history of the universe at different distances for a new measurement of the acceleration of the universe, which should provide clues to the nature of the mysterious dark energy that is driving the acceleration.

Phillips received an A.B. from San Diego State University and a Ph.D. in astronomy from UC-Santa Cruz. After graduate school, he was a postdoctoral associate at both Cerro Tololo Inter-American Observatory (CTIO), and the Anglo-Australian Observatory. He then moved back to Chile in 1982 to become a staff astronomer at CTIO. He was later director of the CTIO  National Optical Astronomy Observatory, before joining Carnegie  in 1998.  For more see http://obs.carnegiescience.edu/users/mmp

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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

An artist’s conception of GN-z11 courtesy of Jingchuan Yu.
December 14, 2020

Pasadena, CA— New work from an international team of astronomers including Carnegie’s Gregory Walth improves our understanding of the most-distant known astrophysical object— GN-z11, a galaxy 13.4 billion light-years from Earth.

Formed 400 million years after the Big Bang, GN-z11 was previously determined by space telescope data to be the most-distant object yet discovered. In two newly published Nature Astronomy papers, a team led by Linhua Jiang at the Kavli Institute for Astronomy and Astrophysics at Peking University took near-infrared spectra using ground-based telescopes that confirmed the galaxy’s distance. They also caught an ultraviolet flash

The Blue Ring Nebula courtesy of Mark Seibert
November 18, 2020

Pasadena, CA— 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 McWilliam revealed that the phenomenon is the extremely difficult-to-spot result of a stellar collision in which two stars merged into one.

Sixteen years ago, NASA’s Galaxy Evolution Explorer (GALEX) spacecraft discovered a large, faint blob of gas with a star at its center—an object unlike anything previously seen in our Milky Way galaxy. The blob is represented as blue in the ultraviolet images of GALEX—although it doesn't actually emit

Carnegie theoretical astrophysicist Anthony Piro engages with the VizLab wall.
November 18, 2020

Pasadena, CA— In a refurbished Southern California garage, Carnegie astrophysicists are creating the virtual reality-enabled scientific workspace of the future where they will unlock the mysteries of the cosmos.

Imagine standing in front of a wave of data and probing the mysteries of the universe’s most-ancient galaxies side-by-side with swirling, colorful simulations of galaxy formation—seeing what aligns with expectations and what needs further interrogation.  A portal to fake universes may sound like science fiction, but it is now a reality at the Carnegie Observatories. 

The campus has just undertaken its new experiential

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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 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

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/

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

Phillip Cleves’ Ph.D. research was on determining the genetic changes that drive morphological evolution. He used the emerging model organism, the stickleback fish, to map genetic changes that control skeletal evolution. Using new genetic mapping and reverse genetic tools developed during his Ph.D., Cleves identified regulatory changes in a protein called bone morphogenetic protein 6 that were responsible for an evolved increase in tooth number in stickleback. This work illustrated how molecular changes can generate morphological novelty in vertebrates.

Cleves returned to his passion for coral research in his postdoctoral work in John Pringles’ lab at Stanford

Brittany Belin joined the Department of Embryology staff in August 2020. Her Ph.D. research involved developing new tools for in vivo imaging of actin in cell nuclei. Actin is a major structural element in eukaryotic cells—cells with a nucleus and organelles —forming contractile polymers that drive muscle contraction, the migration of immune cells to  infection sites, and the movement of signals from one part of a cell to another. Using the tools developed in her Ph.D., Belin discovered a new role for actin in aiding the repair of DNA breaks in human cells caused by carcinogens, UV light, and other mutagens.

Belin changed course for her postdoctoral work, in

Evolutionary geneticist Moises Exposito-Alonso joined the Department of Plant Biology as a staff associate in September 2019. He investigates whether and how plants will evolve to keep pace with climate change by conducting large-scale ecological and genome sequencing experiments. He also develops computational methods to derive fundamental principles of evolution, such as how fast natural populations acquire new mutations and how past climates shaped continental-scale biodiversity patterns. His goal is to use these first principles and computational approaches to forecast evolutionary outcomes of populations under climate change to anticipate potential future