From IAC-The Institute of Astrophysics of the Canary Islands [Instituto de Astrofísica de Canarias](ES): “Solar physicists build a 2D model which can explain the bright points in the solar corona”

Instituto de Astrofísica de Andalucía

From IAC-The Institute of Astrophysics of the Canary Islands [Instituto de Astrofísica de Canarias](ES)

Daniel Nóbrega Siverio

Fernando Moreno Insertis

A numerical experiment conducted by two researchers at the Instituto de Astrofísica de Canarias (IAC), Daniel Nöbrega Siverio and Fernando Moreno Insertis, has allowed them to show, for the first time, how one of the most widely distributed structures in the solar atmosphere, the coronal bright points, can form and acquire energy by the action of the solar granulation.

When the Sun is observed from space detectors of X-rays or the extreme-ultraviolet, its atmosphere is found to be full of bright points, both during solar active epochs when a large number of sunspots is observed, and during quieter epochs. When they are inspected in detail we find that these coronal bright points (CBP) comprise a set of magnetic arcs, which emit huge quantities of energy por periods of hours or even days, probably via a process known as magnetic recombination.

Until now the models of CBPs were highly simplified and did not take into account critical aspects of solar physics ,such as the supply of energy to magnetic structures by solar granules.

In a study recently published in the prestigious journal The Astrophysical Journal Letters [below] Daniel Nóbrega Siverio and Fernando Moreno Insertis, astrophysicists at the IAC, have studied these bright points, using a latest generation numerical code, the Bifrost code. This code allows one to model the Sun with the realism needed to include convective and radiative processes which have a fundamental influence on the heating of the solar atmosphere.

With their model, these researchers show for the first time that the action of the solar granulation on a magnetic structure of the type expected to be found in many CBP gives rise to hot, bright arches, which explains the different features observed during solar space missions for decades. The article also includes predictions of what the cool zones below a CBP are like,and their small scale structure which has not yet been tackled observationally,and which will need data of extremely high resolution, such as those from the Swedish Solar Telescope (SST) on La Palma [below], the the recent Solar Orbiter space mission in order to confirm them.

This study has needed thousands of hours of calculations on two of the most advanced supercomputer facilities in Europe, Betzy (in Norway) and MareNostrum (in Spain). It has been carried out within the Whole Sun project, a programme funded by the European Research Council, in which the IAC is taking part, along with four other European institutions.

Betzy ATOS supercomputer. HPC Wire.

MareNostrum 4 supercomputer at Barcelona Supercomputing Center.

Science paper:
The Astrophysical Journal Letters

See the full article here .


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IAC-The Institute of Astrophysics of the Canary Islands [Instituto de Astrofísica de Canarias](ES) operates two astronomical observatories in the Canary Islands:

Roque de los Muchachos Observatory on La Palma
Teide Observatory on Tenerife.

The Instituto de Astrofísica the headquarters, which is in La Laguna (Tenerife).

Observatorio del Roque de los Muchachos at La Palma (ES) at an altitude of 2400m.

The seeing statistics at ORM make it the second-best location for optical and infrared astronomy in the Northern Hemisphere, after Mauna Kea Observatory Hawai’i.

Maunakea Observatories Hawai’i altitude 4,213 m (13,822 ft).

The site also has some of the most extensive astronomical facilities in the Northern Hemisphere; its fleet of telescopes includes the 10.4 m Gran Telescopio Canarias, the world’s largest single-aperture optical telescope as of July 2009; the Telescopio Nazionale Galileo (IT) (ES) a 3.58-meter Italian telescope; the William Herschel Telescope (second largest in Europe), and the adaptive optics corrected Swedish 1-m Solar Telescope.

Gran Telescopio Canarias [Instituto de Astrofísica de Canarias ](ES) sited on a volcanic peak 2,267 metres (7,438 ft) above sea level.

Isaac Newton Group 4.2 meter William Herschel Telescope at Roque de los Muchachos Observatory on La Palma in the Canary Islands(ES), 2,396 m (7,861 ft).

The Swedish 1m Solar Telescope SST at the Roque de los Muchachos observatory on La Palma Spain, Altitude 2,360 m (7,740 ft).

The observatory was established in 1985, after 15 years of international work and cooperation of several countries with the Spanish island hosting many telescopes from Britain, The Netherlands, Spain, and other countries. The island provided better seeing conditions for the telescopes that had been moved to Herstmonceux by the Royal Greenwich Observatory, including the 98 inch aperture Isaac Newton Telescope (the largest reflector in Europe at that time). When it was moved to the island it was upgraded to a 100-inch (2.54 meter), and many even larger telescopes from various nations would be hosted there.

Tiede Observatory, Tenerife, Canary Islands (ES)

Teide Observatory [Observatorio del Teide], IAU code 954, is an astronomical observatory on Mount Teide at 2,390 metres (7,840 ft), located on Tenerife, Spain. It has been operated by the Instituto de Astrofísica de Canarias since its inauguration in 1964. It became one of the first major international observatories, attracting telescopes from different countries around the world because of the good astronomical seeing conditions. Later the emphasis for optical telescopes shifted more towards Roque de los Muchachos Observatory on La Palma.