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. Shectman was the former project scientist for Magellan and is largely responsible for the superb quality of 6.5-meter telescopes. He is now a member of the Giant Magellan Telescope Project Scientists’ Working Group.

 To understand large-scale structure, Shectman has participated in several galaxy surveys. He and collaborators discovered a particularly large void in the galaxy distribution in the early 1980s and subsequently conducted the Las Campanas Redshift Survey (LCRS) using the C100 fiber spectrograph—a device that collects light, disperses it into spectra to reveal the chemistry and other features. The LCRS was the definitive distance survey of the time and showed that the galaxy distribution becomes homogeneous at large scales compared with the strong fluctuations characteristic of the small-scale distribution.

Hydrogen and helium were produced in the Big Bang, but heavier elements came from nucleosynthesis in successive stellar generations. The oldest stars are deficient in heavy elements, what astronomers call metal-poor. In the 1980s, Shectman and George Preston conducted a survey for these objects. Using novel techniques they discovered the majority of known stars with heavy-element abundances less than about 1% of the Sun’s. Shectman has also worked on metal-poor stars in the Hamburg-ESO survey, using Magellan spectrographs to identify and study the best ones in detail.

 Shectman developed a series of photon-counting detectors for faint-object spectroscopy. They were used at Las Campanas and copied by other observatories. He also built the high-resolution echelle spectrograph and the multiobject fiber spectrograph for the 100-inch du Pont telescope. With Rebecca Bernstein, he built the high-resolution echelle spectrograph for Magellan, which has been in service for several years. He is currently working on the Magellan echellette spectrograph, a joint MIT-Carnegie project with Scott Burles (MIT) and Carnegie’s Ian Thompson, and the Magellan Planet Finder, a collaboration with Carnegie’s Paul Butler and Jeff Crane.

Shectman received his B.S. in physics from Yale Univesity and a Ph. D. in astronomy from Caltech where he was also a National Science Foundation fellow. Before joining the Carnegie staff in 1975, he was a postdoctoral fellow at the University of Michigan. For more information see http://obs.carnegiescience.edu/users/shec

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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

unWISE / NASA/JPL-Caltech / D.Lang (Perimeter Institute).
November 2, 2020

Pasadena, CA- La quinta generación del Sloan Digital Sky Survey recogió sus primeras observaciones del cosmos a la 1:47 a.m. del 24 de octubre de 2020. Este innovador estudio del cielo reforzará nuestra comprensión de la formación y evolución de las galaxias- incluyendo nuestra Vía Láctea- y los agujeros negros supermasivos que acechan en sus centros.  

El recién lanzado SDSS-V continuará la tradición pionera establecida por las generaciones anteriores, con un enfoque en el siempre cambiante cielo nocturno y los procesos físicos que ocurren en los objetos que componen nuestra visió

unWISE / NASA/JPL-Caltech / D.Lang (Perimeter Institute).
November 2, 2020

Pasadena, CA— The Sloan Digital Sky Survey’s fifth generation collected its very first observations of the cosmos at 1:47 a.m. MDT on October 24, 2020. This groundbreaking all-sky survey will bolster our understanding of the formation and evolution of galaxies—including our own Milky Way—and the supermassive black holes that lurk at their centers.  

The newly-launched SDSS-V will continue the path-breaking tradition set by the survey's previous generations, with a focus on the ever-changing night sky and the physical processes that drive these changes, from flickers and flares of supermassive black holes to the back-and-forth shifts of stars

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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