Solar Astronomy
AREA DE ASTRONOMIA

DIF-FUS Universidad de sonora

Besides the rest of Astronomy, the one dedicated to the study of the most essential celestial body for the human species, the Sun, has come with important advances in the last years.

Until now it is clear that the Sun is a small star that stays active on the basis of the fusion of the Hydrogen that happens in its nucleus. The models of the solar interior establish two internal regions where the energy flows: the zone of radiation and the one of convection. Externally we caught the well-known layer Photosphere, from where we received most of the energy. Over the Photosphere, are the Cromosphere and Solar Corona.

The Sun presents a great variety of phenomena from its interior to the most external layer. These phenomena is associated with a 11 year cycle of activity, although it extend to 18 and 22 years. The knowledge of this phenomena is essential to understand the nature and future behavior of this star. The solar phenomena is based on an intense magnetic activity developed by the plasma in circulation at high temperatures.

The emitted solar energy to the interplanetary space because of the regular activity of the Sun, as well as the caused one in special form by great activity phenomena, arrives at the Earth in different ways. Relations established between several solar phenomena and effects in our planet already exist, for example:

• * The solar flares affect our planet causing alterations in the magnetic field, interference in the communications of short wave, interruptions of the electrical power, interference in the cellular telephony and presence of polar and boreal auroras.
• * The high speed solar wind of emitted by Coronal Holes causes geomagnetic disturbances.

Several efforts has been made to find other types of relations between the solar activity and our planet, as it is the weather and the consequences of the ultraviolet radiation on the planet before the damage in Earth's ozone layer. These relations will not be established if the knowledge of the solar physics does not advance .

The study of the solar activity has been improved with the launching of several solar observatories in Earth's orbit. From 1991 the Sun is observed in X rays by Japanese satellite YOHKOH. In 1994 and 1995 the solar poles were studied by the spaceship Ulysses. At the beginning of 1996 the satellite of the NASA/ESA, SOHO started operations, observing in ultraviolet the solar corona. The last year was placed in Earth's orbit the satellite TRACE of  NASA for observation in  high-resolution UV. Other satellites will be placed in Earth orbit to carry out another type of studies, complementing those that are made in the visible one and the infrared from Earth observatories.

In 1999, the cycle number 23 has started its maximum that will continue in 1999-2000 and with an increase in the presence of sunspots, flares and all phenomena related to this one. We are at a very appropriate time to start new efforts to respond the enigma that this star presents, the only one that we can study with detail.

This page is under construction since August 10, 1996.

INVEST IN THE FUTURE...

Last Update: January 22, 2000.