The Center for Astrophysics | Harvard & Smithsonian

The Center for Astrophysics | Harvard & Smithsonian

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Leon Golub

Center for Astrophysics

Senior Astrophysicist, SAO

Leon Golub

lgolub@cfa.harvard.edu

About

I have worked on observations and analysis of solar and stellar magnetic atmospheres since the Skylab missions. Our group, the SSXG, has been and flown numerous innovative instruments on satellites, sounding rockets, high-altitude aircraft and balloons.

Telescopes and Instruments

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

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

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

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.

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.

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