The Center for Astrophysics | Harvard & Smithsonian

The Center for Astrophysics | Harvard & Smithsonian

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High Energy Astrophysics

The Center for Astrophysics | Harvard & Smithsonian High Energy Astrophysics division focuses on X-ray astronomy and instrumentation involved in observations of high-energy sources. This research aims to address the physical processes involved in generating X-rays, the amount of matter in the Universe, and the origin, evolution, and ultimate fate of the Universe.

The High Energy Astrophysics Division's main focus is on X-ray astronomy via observations of high-energy sources with instruments aboard satellites, rockets, balloons, and the Space Shuttle. The Division also develops new instrumentation for future space missions to address the physical processes involved in generating X-rays, the amount of matter in the Universe, and the origin, evolution, and ultimate fate of the Universe.

X-ray astronomy has a short history, but has made rapid progress. Not until 1962 was the first X-ray source outside the Solar System - Scorpius X-1 - detected by a group led by Riccardo Giacconi. Giacconi's group went on to build the first X-ray astronomy satellite, UHURU. Giacconi moved his group to the newly formed CfA in 1973 to found the High Energy Astrophysics Division (HEA), where they led the team building the first X-ray astronomy satellite to use a mirror to take images of the universe in X-rays, the Einstein Observatory, and was over 100 times more sensitive than any previous mission. Now the Chandra X-ray Observatory continues this record, giving the most detailed images of the X-ray sky ever taken. Chandra detects sources 1 billion times fainter than Scorpius X-1, and locates them 10 billion times more precisely. A program in solar X-ray astronomy, started by Pippo Vaiana, made similarly great strides.

The Center for Astrophysics | Harvard & Smithsonian High Energy Astrophysics (HEA) division was founded in 1973 through the merging of high-energy scientists at the Smithsonian Astrophysical Observatory with a new group led by Dr. Riccardo Giacconi (Nobel Prize in Physics, 2002). Over the past 40 years, HEA has grown from a group of about 10 scientists to a combined staff of approximately 300, with 90 scientists and 30 postdoctoral fellows. Additionally, The CfA’s HEA division operates Chandra, NASA’s flagship X-ray Observatory.

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Projects

AstroAI

Atomic and Molecular Physics, High Energy Astrophysics, Optical and Infrared Astronomy, Radio and Geoastronomy, Solar, Stellar, and Planetary Sciences, Theoretical Astrophysics, Harvard University Department of Astronomy, Science Education Department, Central Engineering, Director's Office, Chandra X-ray Center, Institute for Theoretical Atomic Molecular and Optical Physics, Institute for Theory and Computation

AstroAI is a institute dedicated to the development of artificial intelligence to enable next generation astrophysics at the Center for Astrophysics | Harvard & Smithsonian. Learn More

AtomDB

High Energy Astrophysics

In extreme environments, where pressure, temperature, and density are high, atoms change the way they emit and absorb light. Electrons are stripped from nuclei, forming a plasma, and the ions emit X-rays when struck by free electrons. To assist astronomers in identifying atoms under these harsh conditions, the Center for Astrophysics | Harvard & Smithsonian maintains the AtomDB database of X-ray spectra. This catalog provides essential information for studying conditions in many astrophysical environments, including those near black holes, stars, and neutron stars.

DASCH (Digital Access to a Sky Century @ Harvard)

High Energy Astrophysics

The Harvard Astronomical Glass Plate Collection is an archive of roughly 500,000 images of the sky preserved on glass photographic plates, the way professional astronomers often captured images in the era before the dominance of digital technology. These plates are more than historical curiosities: they provide over a century’s worth of data that can be used by contemporary astronomers to trace how objects in the night sky change over periods from years to decades.

For that reason, the DASCH (Digital Access to a Sky Century @ Harvard) team are working to digitize the plates for digital storage and analysis. The process can also lead to new discoveries in old images, particularly of events that change over time, such as variable stars, novas, or black hole flares.

Sensing the Dynamic Universe

High Energy Astrophysics, Optical and Infrared Astronomy, Solar, Stellar, and Planetary Sciences, Science Education Department

The Sensing the Dynamic Universe (SDU) project creates sonified videos exploring the multitude of celestial variables such as stars, supernovae, quasars, gamma ray bursts and more. We sonify lightcurves and spectra, making the astrophysics of variables and transients accessible to the general public, with particular attention to accessibility for those with visual and/or neurological differences.

SDU Website

ChaMP (Chandra Multiwavelength Project) and ChaMPlane (Chandra Multiwavelength Plane) Survey

High Energy Astrophysics

NASA’s Chandra X-ray Observatory is a groundbreaking space telescope, with abilities beyond anything that came before it. The Chandra Multiwavelength Project (ChaMP) and Chandra Multiwavelength Plane (ChaMPlane) Survey exploit those abilities to catalog the variety of X-ray sources within archival Chandra data, with follow-up using other telescopes in other parts of the spectrum of light. The surveys identified previously unknown galaxy clusters, quasars, neutron star binary systems, and other significant astronomical sources both in the plane of the Milky Way — ChamPLane — and beyond the galaxy — ChaMP. ChaMP and ChaMPlane are led by astronomers at the Center for Astrophysics | Harvard & Smithsonian, in collaboration with researchers at a number of other institutions in the United States and around the world.

Chandra Supernova Remnant Catalog

High Energy Astrophysics

Galaxies are littered with supernova remnants: expanding clouds of material blasted out during the explosions of massive stars. These remnants are complex: full of strong magnetic fields, high-temperature collisions between particles, and flows of material into interstellar space. The clouds are rich environments that provide raw materials for future star formation, as well as laboratories for studying extreme astrophysics. For that reason, the Chandra Supernova Remnant Catalog collects the available observational data collected by NASA’s Chandra X-ray Observatory about supernova remnants in the Milky Way and our neighboring galaxies, the Magellanic Clouds. The catalog is managed by astronomers at the Center for Astrophysics | Harvard & Smithsonian, and includes information about the remnants’ shapes and X-ray spectra, along with corresponding radio observations for some specimens.

Telescopes and Instruments

1.2 Meter (48-inch) Telescope

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.

Visit the 1.2-Meter (48 Inch) Telescope Website

1.5-meter Tillinghast (60-inch) Telescope

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

Visit the 1.5 Meter (60 Inch) Tillinghast Telescope Website

AIR-Spec/ASPIRE

The Sun generates a powerful magnetic field, which drives the solar storms that occasionally batter the worlds of the Solar System. However, the magnetic fields in the solar corona are very hard to observe, despite their importance in creating space weather. For that reason, scientists at the Center for Astrophysics | Harvard & Smithsonian developed the Airborne Infrared Spectrometer (AIR-Spec), an instrument carried aboard an airplane to measure the properties and effects of the coronal magnetic field during solar eclipses, where the corona is most plainly visible. AIR-Spec was inaugurated during the 2017 total solar eclipse visible across the United States; an improved version will fly during the 2019 eclipse visible from South America and the southern Pacific Ocean.

Visit the AIR-Spec Website

Arcus

The most powerful astronomical events are often very bright in X-rays, including supermassive black holes, the hot atmospheres of stars, and the extremely hot plasmas in and around galaxy clusters. Arcus is a proposed NASA space telescope designed to study the X-ray spectrum of a wide range of astronomical phenomena to a level of sensitivity higher than any previous X-ray observatory. Center for Astrophysics | Harvard & Smithsonian scientists are the leaders of the collaboration proposing Arcus. The mission proposal will be due in late 2023 and, if ultimately accepted, Arcus would launch in 2031.

See Arcus Website

Chandra

The Chandra X-ray Observatory is NASA’s flagship X-ray observatory, providing essential data on everything from the environment surrounding newborn stars to the emissions from hot plasma inside galaxy clusters. The Smithsonian Astrophysical Observatory (SAO), as part of the Center for Astrophysics | Harvard & Smithsonian, manages Chandra’s day-to-day operations, providing spacecraft control, observation planning, and data processing for astronomers. Chandra is one of NASA’s orbiting Great Observatories, along with the Hubble.

Visit the Chandra Website

Einstein Observatory

NASA’s Einstein Observatory was the first X-ray space telescope designed to produce images of astronomical X-ray sources. The spacecraft operated from 1978 through 1981, providing important observations of pulsars, supernova remnants, supermassive black holes in other galaxies, and many more, paving the way for NASA’s Chandra X-ray Observatory. The X-ray telescope was designed by researchers at the Center for Astrophysics | Harvard & Smithsonian.

High Resolution Coronal Imager (Hi-C)

Why the Sun’s corona — the wispy outermost atmosphere — is so much hotter than its surface stands as a big mystery in solar science. NASA’s High-Resolution Coronal Imager (Hi-C) is an ultraviolet telescope designed to help solve the mystery, and understand the processes by which the Sun sends violent storms of particles into the Solar System. Since most of the light from the Sun’s atmosphere is blocked by air molecules on Earth, Hi-C is carried on a short-flight rocket into Earth’s upper atmosphere. Since 2012, Hi-C has flown three times, providing the highest resolution images of the corona and revealing new details in the Sun’s atmosphere. Hi-C is jointly operated by NASA's Marshall Space Flight Center (MSFC) and the Center for Astrophysics | Harvard & Smithsonian, with contributions from other researchers around the world.

Visit the Hi-C Website

Hinode

The Sun is the closest star to Earth, and the single most important influence on the worlds of the Solar System in terms of the light and particles it emits. Studying the Sun, in other words, helps us understand the habitability of Earth, but also other stars elsewhere in the universe. One important solar observatory is the Japanese Aerospace Exploration Agency’s Hinode spacecraft, which carries three powerful instruments to study the Sun in X-rays, visible light, and ultraviolet light. Center for Astrophysics | Harvard & Smithsonian engineers collaborated in the development of the X-ray Telescope for the spacecraft. Hinode has been observing the Sun continuously since its launch in 2006, providing important day-by-day information about our host star’s activity.

Visit the Hinode/XRT Website

Interface Region Imaging Spectrograph (IRIS)

The Sun’s surface is incandescently hot, but its outer atmosphere — the corona — is far hotter, for reasons astronomers don’t fully understand. NASA’s Interface Region Imaging Spectrograph (IRIS) is an orbiting observatory designed to study the mysterious transitional part of the Sun’s lower atmosphere, where the heating of the material flowing into the corona takes place. Understanding the heating process may help predict solar storms as well. Scientists and engineers from the Center for Astrophysics | Harvard & Smithsonian contributed to the telescope for IRIS. In addition, CfA researchers participate in telescope operations, and provide scientific support and analysis for the observatory’s work.

Visit the IRIS Website

Lynx X-Ray Observatory

The Lynx X-ray Observatory is a proposed X-ray space telescope, designed to be the next generation following NASA’s Chandra X-ray Observatory and the European Space Agency’s upcoming Athena Telescope. This observatory will be able to take images of a larger area of the sky in X-ray light with better resolution than any existing telescope, allowing astronomers to study the first supermassive black holes, the hot gas surrounding galaxies as they evolve, and radiation from the earliest stars. Researchers from the Center for Astrophysics | Harvard & Smithsonian and other universities are presenting Lynx to NASA for consideration in the 2020 Decadal Survey, with a proposed launch date in the mid-2030s.

Visit the Lynx X-Ray Observatory Website

MMT Observatory

The MMT Observatory is the premier visible-light and infrared telescope jointly managed by the Smithsonian Astrophysical Observatory, part of the Center for Astrophysics | Harvard & Smithsonian, and the University of Arizona. Located at the 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 the CfA and the University of Arizona.

Visit the MMT Website

Pan-STARRS-1 Science Consortium

Many objects in the sky don’t change or move visibly on human time scales. However, many others do, especially objects in the Solar System. The Panoramic Survey Telescope and Rapid Response System (Pan-STARRS) program is designed to monitor the sky for transient astronomical phenomena: everything from near-Earth asteroids to supernovas in far-off galaxies. The first phase of the program, Pan-STARRS1, used a 1.8-meter telescope on the summit of Haleakalā on the island of Maui in Hawaii. The Center for Astrophysics | Harvard & Smithsonian is part of the international Pan-STARRS1 Science consortium, along with the University of Hawaii and other institutions around the world. Pan-STARRS1 data revealed many asteroids, comets, and other previously-unknown moving or variable astronomical objects.

Visit the Pan-STARRS1 Science Consortium Website

Parker Solar Probe

What is driving the solar wind? Some particles in the Sun’s atmosphere gain enough speed to escape the Sun’s gravitational pull and bombard the worlds of the Solar System, but the processes behind the phenomenon are still mysterious. To solve that mystery, NASA’s Parker Solar Probe spacecraft was built to fly through the Sun’s atmosphere, performing the first up-close solar measurements in history. Scientists and engineers at the Center for Astrophysics | Harvard & Smithsonian built the Solar Probe Cup (SPC) instrument for the spacecraft. SPC is part of the Solar Wind Electrons Alphas and Protons (SWEAP) instrument suite used to sample particles directly from the Sun’s atmosphere for analysis.

Visit the Parker Solar Probe SWEAP Website

Solar Dynamics Observatory (SDO)

The Sun is both life-giving and dangerous. Variations in the Sun’s light and wind have profound effects on Earth, while solar storms can wreak havoc on power and communications systems. NASA’s Solar Dynamics Observatory (SDO) is a spacecraft dedicated to studying these potentially dangerous variations, and the magnetic fields that drive them. Engineers at the Center for Astrophysics | Harvard & Smithsonian contributed to the design and construction of the four Atmospheric Imaging Array (AIA) telescopes. AIA is one of the three major experiments carried by SDO.

Visit the SDO Website

Spitzer Space Telescope

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.

Visit the Spitzer Space Telescope IRAC Page

The Coronal Spectrographic Imager in the EUV (COSIE)

Space weather is a matter of concern for all of us: storms from the Sun can disrupt global communications and electrical power grids. However, we still don’t understand exactly how these storms are formed, much less how to predict them. To complement existing solar observations, the Coronal Spectrographic Imager in the EUV (COSIE) is a proposed telescope for use on the International Space Station, designed to view the Sun in extreme ultraviolet (EUV) light. If the project is selected, COSIE would provide a thousand times improvement in EUV observations of the Sun’s atmosphere over existing telescopes, providing a better means of spotting and predicting solar storms. COSIE is a proposal by researchers at the Center for Astrophysics | Harvard & Smithsonian, who are also developing the technology to make the instrument possible.

Transition Region and Coronal Explorer (TRACE)

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.

Uhuru

The Uhuru X-ray Explorer Satellite was the first spacecraft dedicated to X-ray astronomy. During its mission in the early 1970s, Uhuru mapped the X-ray sky. It provided the first observational evidence for black holes, revealed that galaxy clusters contain hot X-ray-emitting gas, and charted the behavior of neutron stars in binary systems. The observatory was named Uhuru, the Swahili word meaning “freedom”, in honor of Kenyan independence and because the rocket carrying the spacecraft was launched into orbit from a site off the coast of Kenya near Mombasa. The success of the Uhuru satellite led the way for all subsequent space telescopes, from the Einstein Observatory to NASA’s flagship Chandra X-ray Observatory.

Wind Spacecraft

NASA’s Wind Spacecraft has observed the Sun ever since its launch in 1994, making it one of the most successful and longest-running space observatories. Orbiting at a special location between Earth and the Sun, Wind measures the properties of the electrically-charged particles known as the solar wind. Scientists from the Center for Astrophysics | Harvard & Smithsonian currently operate one of Wind’s instruments, which collects ions from the solar wind. Data from the spacecraft have been used in over 4,500 journal articles, doctoral dissertations, and other scientific publications. Wind was built to last: it has enough fuel to keep operating for another 50 years.

Visit the Wind Spacecraft Website