A corona is the outermost layer of a star's atmosphere. It consists of plasma.
Sunspots are phenomena on the Sun's photosphere that appear as temporary spots that are darker than the surrounding areas. They are regions of reduced surface temperature caused by concentrations of magnetic flux that inhibit convection. Sunspots appear within active regions, usually in pairs of opposite magnetic polarity. Their number varies according to the approximately 11-year solar cycle.
The Goddard Space Flight Center (GSFC) is a major NASA space research laboratory located approximately 6.5 miles (10.5 km) northeast of Washington, D.C. in Greenbelt, Maryland, United States. Established on May 1, 1959 as NASA's first space flight center, GSFC employs about 10,000 civil servants and contractors. Named for American rocket propulsion pioneer Robert H. Goddard, it is one of ten major NASA field centers. GSFC is partially within the former Goddard census-designated place; it has a Greenbelt mailing address.
The Solar and Heliospheric Observatory (SOHO) is a European Space Agency (ESA) spacecraft built by a European industrial consortium led by Matra Marconi Space that was launched on a Lockheed Martin Atlas IIAS launch vehicle on 2 December 1995, to study the Sun. It has also discovered over 5,000 comets. It began normal operations in May 1996. It is a joint project between the European Space Agency (ESA) and NASA. SOHO was part of the International Solar Terrestrial Physics Program (ISTP). Originally planned as a two-year mission, SOHO continues to operate after over 25 years in space; the mission has been extended until the end of 2025, subject to review and confirmation by ESA's Science Programme Committee.
The National Solar Observatory (NSO) is a United States federally funded research and development center to advance the knowledge of the physics of the Sun. NSO studies the Sun both as an astronomical object and as the dominant external influence on Earth. NSO is headquartered in Boulder and operates facilities at a number of locations - at the 4-meter Daniel K. Inouye Solar Telescope in the Haleakala Observatory on the island of Maui, at Sacramento Peak near Sunspot in New Mexico, and six sites around the world for the Global Oscillations Network Group one of which is shared with the Synoptic Optical Long-term Investigations of the Sun.
Transition Region and Coronal Explorer was a NASA heliophysics and solar observatory designed to investigate the connections between fine-scale magnetic fields and the associated plasma structures on the Sun by providing high resolution images and observation of the solar photosphere, the transition region, and the solar corona. A main focus of the TRACE instrument is the fine structure of coronal loops low in the solar atmosphere. TRACE is the third spacecraft in the Small Explorer program, launched on 2 April 1998, and obtained its last science image on 21 June 2010, at 23:56 UTC.
The Center for Astrophysics | Harvard & Smithsonian (CfA), previously known as the Harvard–Smithsonian Center for Astrophysics, is an astrophysics research institute jointly operated by the Harvard College Observatory and Smithsonian Astrophysical Observatory. Founded in 1973 and headquartered in Cambridge, Massachusetts, United States, the CfA leads a broad program of research in astronomy, astrophysics, Earth and space sciences, as well as science education. The CfA either leads or participates in the development and operations of more than fifteen ground- and space-based astronomical research observatories across the electromagnetic spectrum, including the forthcoming Giant Magellan Telescope (GMT) and the Chandra X-ray Observatory, one of NASA's Great Observatories.
The Lockheed Martin Solar and Astrophysics Laboratory (LMSAL) is part of the Lockheed Martin Advanced Technology Center (ATC) that is known primarily for its scientific work in the field of solar physics, astronomy and space weather. The LMSAL team is part of Lockheed Martin Space Systems and has close affiliations with NASA and the solar physics group at Stanford University.
STEREO is a solar observation mission. Two nearly identical spacecraft were launched in 2006 into orbits around the Sun that cause them to respectively pull farther ahead of and fall gradually behind the Earth. This enabled stereoscopic imaging of the Sun and solar phenomena, such as coronal mass ejections.
The Solar Dynamics Observatory (SDO) is a NASA mission which has been observing the Sun since 2010. Launched on 11 February 2010, the observatory is part of the Living With a Star (LWS) program.
The Daniel K. Inouye Solar Telescope (DKIST) is a scientific facility for studies of the Sun at Haleakala Observatory on the Hawaiian island of Maui. Known as the Advanced Technology Solar Telescope (ATST) until 2013, it was named after Daniel K. Inouye, a US Senator for Hawaii. It is the world's largest solar telescope, with a 4-meter aperture. The DKIST is funded by National Science Foundation and managed by the National Solar Observatory. The total project cost is $344.13 million. It is a collaboration of numerous research institutions. Some test images were released in January 2020. The end of construction and transition into scientific observations was announced in November 2021.
In solar physics, a coronal loop is a well-defined arch-like structure in the Sun's atmosphere made up of relatively dense plasma confined and isolated from the surrounding medium by magnetic flux tubes. Coronal loops begin and end at two footpoints on the photosphere and project into the transition region and lower corona. They typically form and dissipate over periods of seconds to days and may span anywhere from 1 to 1,000 megametres in length.
Interface Region Imaging Spectrograph (IRIS), also called Explorer 94 and SMEX-12, is a NASA solar observation satellite. The mission was funded through the Small Explorer program to investigate the physical conditions of the solar limb, particularly the interface region made up of the chromosphere and transition region. The spacecraft consists of a satellite bus and spectrometer built by the Lockheed Martin Solar and Astrophysics Laboratory (LMSAL), and a telescope provided by the Smithsonian Astrophysical Observatory (SAO). IRIS is operated by LMSAL and NASA's Ames Research Center.
The Heliophysics Science Division of the Goddard Space Flight Center (NASA) conducts research on the Sun, its extended Solar System environment, and interactions of Earth, other planets, small bodies, and interstellar gas with the heliosphere. Division research also encompasses geospace—Earth's uppermost atmosphere, the ionosphere, and the magnetosphere—and the changing environmental conditions throughout the coupled heliosphere.
Louise Harra is a Northern Irish physicist, born in Lurgan, County Armagh, Northern Ireland. She is the Director of the World Radiation Centre of the Physical Meteorological Observatory in Davos (PMOD/WRC) and affiliated professor at the Institute of Particle Physics and Astrophysics of ETH Zurich.
Barbara June Thompson is an American solar physicist. She is a scientist at Goddard Space Flight Center where she researches coronal mass ejections and the dynamics of coronal structures. Thompson was the project scientist for NASA's Solar Dynamics Observatory mission through development and early flight.
Joan T. Schmelz is the Associate Director for Science and Public Outreach at the Stratospheric Observatory for Infrared Astronomy (SOFIA) for the Universities Space Research Association (USRA). Previously, Schmelz was the Deputy Director of Arecibo Observatory and the Director of USRA Operations at Arecibo from 2015 through 2018. Before joining USRA, Schmelz was an NSF Program Director in the Astronomical Sciences Division, where she oversaw the Astronomy & Astrophysics Postdoctoral Fellowship program, and a professor of physics at the University of Memphis from 1996 to 2017. Schmelz's research focus is heliophysics, specifically investigating the coronal heating problem as well as the properties and dynamics of the solar atmosphere. She uses spectroscopic and image data in the X-ray and ultraviolet wavelength ranges obtained from NASA satellites and rockets. She has published over 80 refereed scientific journal articles and authored three books.
Supra-arcade downflows (SADs) are sunward-traveling plasma voids that are sometimes observed in the Sun's outer atmosphere, or corona, during solar flares. In solar physics, arcade refers to a bundle of coronal loops, and the prefix supra indicates that the downflows appear above flare arcades. They were first described in 1999 using the Soft X-ray Telescope (SXT) on board the Yohkoh satellite. SADs are byproducts of the magnetic reconnection process that drives solar flares, but their precise cause remains unknown.
The Institute of Theoretical Astrophysics is a research and teaching institute dedicated to astronomy, astrophysics and solar physics located at Blindern in Oslo, Norway. It is a department of The Faculty of Mathematics and Natural Sciences at the University of Oslo. It was founded in its current form by Svein Rosseland with funding from the Rockefeller Foundation in 1934, and was the first of its kind in the world when it opened. Prior to that, it existed as the University Observatory which was created in 1833. It thus is one of the university's oldest institutions. As of 2019, it houses research groups in cosmology, extragalactic astronomy, and The Rosseland Centre for Solar Physics, a Norwegian Centre of Excellence.
Dr Natchimuthuk "Nat" Gopalswamy is an Indian American Solar physicist. He is currently a staff scientist at the Heliophysics Division of NASA’s Goddard Space Flight Center.
