The Center for Astrophysics | Harvard & Smithsonian

The Center for Astrophysics | Harvard & Smithsonian

Support Our Science

Nishu Karna

Center for Astrophysics

Nishu Karna

nishu.karna@cfa.harvard.edu

About

I am a solar physicist in the Solar and Stellar X-ray Group at CfA. My research focuses on studying the long term evolution of coronal holes, coronal cavities, and prominences/filaments. I also produce non-linear force-free field magnetic models of active regions, prominences, cavities, and pseudostreamers.

P.hD

Telescopes and Instruments

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

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

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

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

Deep Space Climate Observatory (DSCOVR)

Understanding climate change requires an understanding of Earth as a planet. The Deep Space Climate Observatory (DSCOVR) is a joint NASA-NOAA space observatory with two tasks: real-time tracking of conditions on Earth, and monitoring the solar wind — electrically charged particles streaming from the Sun. DSCOVR’s vantage point is a stable orbit between Earth and the Sun, allowing it to give us as much as an hour’s warning before solar storms hit, in addition to regularly-updated full-Earth images. Center for Astrophysics | Harvard & Smithsonian researchers collaborated on one of DSCOVR’s solar-wind instruments.

Visit the DSCOVR Website

Solar and Heliospheric Observer (SOHO)

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.

Visit the SOHO/UVCS Website