Solar, Stellar, and Planetary Sciences

The 1.2-Meter (48 Inch) Telescope is a general purpose visible-light telescope located at the Fred Lawrence Whipple Observatory (FLWO), a major observational facility of the Center for Astrophysics | Harvard & Smithsonian located in southern Arizona. Astronomers use this telescope to observe objects in the Solar System and the Milky Way, as well as other galaxies, including the supermassive black holes known as quasars. Astronomers also use the 1.2-Meter Telescope to observe star systems that might contain exoplanets, which is a major program for the observatory.

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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.

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The 1.5-Meter (60 Inch) Tillinghast Telescope is a general purpose visible-light telescope located at the Fred Lawrence Whipple Observatory (FLWO) in southern Arizona, operated by the Center for Astrophysics | Harvard & Smithsonian. Astronomers use this telescope to measure the spectrum of light emitted by a wide variety of objects in the Solar System, the Milky Way, and in distant galaxies.

CfA Operated (OIR) | Open to CfA Scientists | Active

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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.

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Measuring the mass of a distant exoplanet requires tracking the changes in light of the host star as the planet’s gravity tugs it slightly — a delicate process. The High Accuracy Radial velocity Planet Searcher for the Northern hemisphere (HARPS-N) is an instrument designed for that purpose. HARPS-N is installed on the Telescopio Nazionale Galileo at the Roque de los Muchachos Observatory on the island of La Palma in the Canary Islands. The instrument provides valuable follow-up observations for the smaller exoplanets identified by NASA’s Kepler/K2 space telescope and other observatories. Astronomers at the Center for Astrophysics | Harvard & Smithsonian are part of the international collaboration operating the instrument. Using the high quality data from HARPS-N, astronomers hope to measure the masses of Earth-like worlds to sufficient accuracy to determine how much these planets resemble ours.

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The Hungarian-made Automated Telescope Network (HATNet) is a set of computer-controlled small telescopes located at various observatories around the world. Five of these telescopes are hosted at the Fred Lawrence Whipple Observatory (FLWO), a Center for Astrophysics | Harvard & Smithsonian facility in southern Arizona. HATNet is designed to look for planets in orbit around bright stars; since beginning operations in 2001, astronomers have used the network to identify 70 confirmed exoplanets and several hundred additional candidates that have not yet been confirmed as exoplanets or ruled out as false positives.

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Since the early 1990s, astronomers have identified thousands of planets orbiting other stars. Most of those identifications have come thanks to one observatory: NASA’s Kepler space telescope. Until it lost its ability to point, Kepler observed a region of the sky containing about 150,000 stars with potential planets, monitoring them for the slight decrease in light caused by planets crossing in front of the star. After the spacecraft’s pointing control failed, the mission was renamed K2, and it continued to hunt for exoplanets as it tumbled slowly, with its field of view drifting slowly across the sky. The mission finally ended in 2018, though the data it produced continues to provide astronomers with valuable information about planets in our galactic neighborhood. Astronomers from the Center for Astrophysics | Harvard & Smithsonian were responsible for the preparation of the catalog for potentially interesting stars, and have participated extensively in follow-up observations of Kepler planetary discoveries.

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The twin Magellan Telescopes in Chile are each 6.5 meter optical telescopes. These telescopes are both equipped with instruments to take images and spectra of light from a wide variety of astronomical sources, including exoplanet systems, star-forming regions, supernova remnants, and interacting galaxies. The Magellan Telescopes — named Baade and Clay —  are hosted at the Las Campanas Observatory and are operated by a consortium of institutions, including the Center for Astrophysics | Harvard & Smithsonian, Carnegie Institution for Science, University of Arizona, the University of Michigan, and the Massachusetts Institute of Technology. In addition, CfA scientists and engineers provided a wide field f/5 focal system (including secondary mirror and corrective optics), and a powerful astronomical camera for use at the Clay telescope.

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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.

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Finding potentially habitable exoplanets is a major goal of modern astronomy, but Earth-like worlds in Earth-like orbits are hard to detect. The MINiature Exoplanet Radial Velocity Array (MINERVA) project is a set of small telescopes designed to look at two related but simpler systems: Earth-size planets close to their host stars, and “super-Earths” in more Earth-like orbits. MINERVA is a collaboration between the Center for Astrophysics | Harvard & Smithsonian, the University of Montana, Penn State, the University of Southern Queensland, and the University of Pennsylvania. The telescopes are hosted at the CfA’s Fred Lawrence Whipple Observatory (FLWO) in Arizona.

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The MMT Observatory is the premier visible-light and infrared telescope operated by the Center for Astrophysics | Harvard & Smithsonian. Located at the CfA’s Fred Lawrence Whipple Observatory (FLWO) in southern Arizona, this 6.5-meter (21 foot) telescope is used to study objects across the field of astronomy, from the Solar System to distant galaxies. The MMT has provided a testbed for new telescope technologies developed by scientists and engineers at CfA and the University of Arizona, which jointly operate the MMT Observatory.

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The Sun is the only star we can study in detail, providing us with the opportunity to observe stellar internal structure, magnetic fields, and atmosphere. Solar and Heliospheric Observer (SOHO), a space observatory jointly operated by NASA and the European Space Agency (ESA), has been one of the best sources for that knowledge. Originally designed to operate for two years, SOHO has provided daily data on the Sun for more than twenty years, making it one of the longest running space observatories. During that time, SOHO has monitored the Sun’s atmosphere, surface, and seismology, using a wide range of scientific instruments. Scientists and engineers at the Center for Astrophysics | Harvard & Smithsonian developed the instrument SOHO uses to measure the ultraviolet spectrum of the Sun.

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Infrared light is the key to studying a wide range of astronomical systems, including newborn stars and planets, dust in distant galaxies, and material swirling around black holes. The Spitzer Space Telescope was NASA’s orbiting infrared observatory, and part of NASA’s Great Observatories program, along with the Chandra X-ray Observatory and the Hubble Space Telescope. Scientists and engineers at the Center for Astrophysics | Harvard & Smithsonian led the design, testing, and construction of the Infrared Array Camera (IRAC). The Spitzer Space Telescope was launched in 2003 and retired in 2020.

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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.

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The Transition Region and Coronal Explorer (TRACE) was a space-based solar observatory which operated from 1998 through 2010. TRACE primarily observed in ultraviolet light to map the small-scale structure of the eruptions of gas on the Sun’s surface known as coronal loops, as well as the “transition region” where the Sun’s atmosphere increases in temperature dramatically. The telescope was a joint project of the Center for Astrophysics | Harvard & Smithsonian, NASA, and Lockheed Martin. The long duration of the mission enabled TRACE to be the second space-based solar observatory to monitor an entire sunspot cycle, which provided valuable information on how the Sun’s magnetic field affects its atmosphere.