The Center for Astrophysics | Harvard & Smithsonian

The Center for Astrophysics | Harvard & Smithsonian

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Juliana García-Mejía

Center for Astrophysics

Juliana García-Mejía

juliana.garcia-mejia@cfa.harvard.edu

About

Juliana García-Mejía is a final year graduate student at the CfA, as well as a Ford Foundation and NSF Fellow. Her research is focused on the development of novel astronomical instrumentation to enable the study of exoplanets, M dwarfs, and eventually the search for biosignatures on other planets. She is the PI of The Tierras Observatory, a new 1.3m ultra-precise fully-automated photometric observatory located atop Mt. Hopkins, Arizona. She is also a co-investigator in the FIOS project, a Fabry-Perot instrument designed for use on the Giant Magellan Telescope to detect oxygen in exoplanet atmospheres. Juliana is invested in promoting equity and inclusion within Astronomy and STEM, with particular attention towards engaging young Colombian students with the millenary question of whether life exists elsewhere in the Universe. This goal is embedded into the name of the Tierras observatory, as well as its logo. In her spare time, Juliana enjoys reading, cycling, training for triathlons, and dancing.

Harvard College '17, Harvard Astronomy PhD (2017 - Present)

Telescopes and Instruments

Giant Magellan Telescope

Is Earth unique, or are there other planets with life in the Milky Way? To answer this question and many others, astronomers need larger and more sensitive observatories than anything we currently have. For that reason, the Center for Astrophysics | Harvard & Smithsonian is collaborating with a number of other institutions around the world to create the Giant Magellan Telescope (GMT), currently under construction in Chile. The GMT will consist of seven large mirrors acting in concert as one giant telescope 80 feet across. That large size provides an unprecedented view of the sky and the ability to detect the chemical composition of exoplanet atmospheres. Like NASA’s Hubble Space Telescope, the GMT will be a powerful tool across the field of astronomy, providing insights into the formation of planets, the structure of galaxies, and the evolution of the universe itself.

Visit the GMT Website

MEarth

How many Earth-sized planets are out there? How many of those might support life? Answering these questions is complicated because Earth-like worlds are small, making them hard to detect. The MEarth Project — pronounced “mirth” — simplifies the problem by looking for planets orbiting small, red M dwarf stars. Potentially habitable Earth-sized planets have smaller orbits around these stars than yellow Sun-like stars, allowing MEarth to identify them. The MEarth telescopes are operated by the Center for Astrophysics | Harvard & Smithsonian and located at the CfA’s Fred Lawrence Whipple Observatory (FLWO) in Arizona and the Cerro Tololo Inter-American Observatory (CTIO) in Chile. Astronomers have used MEarth to identify multiple planets, including the rocky planet GJ1132b.

Visit the MEarth Website

Transiting Exoplanet Survey Satellite (TESS)

Astronomers have discovered thousands of planets orbiting other stars. Extrapolating from that knowledge, the Milky Way alone is probably home to hundreds of billions of planets, many of which are likely rocky, Earth-like worlds. NASA’s Transiting Exoplanet Survey Satellite (TESS) is a space observatory designed to look for exoplanets in orbit around 200,000 nearby bright stars, with a particular interest in identifying small planets. Astronomers from the Center for Astrophysics | Harvard & Smithsonian are part of the scientific team to analyze TESS data, as well as performing follow-up observations. The relative closeness of worlds in the TESS survey will allow astronomers to even study some of their atmospheres, using the future Giant Magellan Telescope (GMT) and other observatories. TESS observational program is complementary to NASA’s long-running Kepler/K2 mission, and could identify as many as 20,000 new exoplanet orbiting a wide variety of star types.

Visit the TESS Website

1.3 Meter Telescope

The Two Micron All-Sky Survey (2MASS) was an ambitious project to map the entire sky in infrared light, providing a cosmic census of galaxies, star clusters, small Solar System bodies, and many more. 2MASS used two telescopes: the 1.3 Meter Telescope operated by the Center for Astrophysics | Harvard & Smithsonian, located at the Fred Lawrence Whipple Observatory (FLWO) in southern Arizona; and an identical instrument operated by the Cerro Tololo Inter-American Observatory in Chile. The survey was concluded in the late 1990s, making the telescope available to CfA astronomers and collaborators for new projects. The telescope was converted to automatic control, and renamed Peters Automated Infrared Imaging Telescope (PAIRITEL), for a program monitoring transient events such as supernovas and gamma-ray bursts. The PAIRITEL project ran from 2003 to 2012. Plans are underway in 2019 to reconfigure the telescope for visible-light measurements to hunt for exoplanets.

Visit the 1.3 Meter Telescope Website