New Radiotelescopes Make Solar Flare Studies Possible
It follows one article published on the day (12/21) in the website of the "Agência FAPESP” noting that a new Radio Telescopes make new Solar Flare Studies possible.
New Radio Telescopes Make
New Solar Flare Studies Possible
By Fábio Castro
December 21, 2011
the only ones of their kind, are
installed at the Argentine Observatory
Agência FAPESP – A group of Brazilian scientists led the installation of two solar polarimetric radio telescopes in Argentina on November 22. These instruments are the only ones in the world that operate between 20 and 200 gigahertz, filling an enormous gap that had impeded the study of many aspects related to solar flares.
The project “Solar patrol polarization telescopes at 45 and 90 GHz,” financed by FAPESP under its Regular Research Support program, is coordinated by Adriana Válio, professor at the Universidade Presbiteriana Mackenzie School of Engineering, and by Pierre Kaufmann, coordinator of the Mackenzie Center of Radioastronomy and Astrophysics (CRAAM).
The instruments will be operated under an agreement that has involved scientists from the CRAAM and the observatory at the El Leoncito Astronomical Complex (CASLEO) in San Juan, Argentina, for the past 11 years. The radio telescopes have been installed and aligned and have already begun working.
According to Kaufmann, the two millimeter wave radio telescopes will allow for observations at 45 and 90 gigahertz, respectively.
As Kaufmann told the Agência FAPESP, "They are the only operational radio telescopes of this type in the world today. Their measurements will complement spectrums of solar flares observed at higher frequencies at CASLEO—from 200 to 400 gigahertz—and at frequencies lower than 20 gigahertz, obtained with instruments in the United States."
The gap in the band of frequencies from 20 to 200 gigahertz has not only limited studies on certain parameters of solar flares, but has caused many complications in interpreting results obtained with existing instruments.
“It is a very critical band about which the scientific community has no information. The new instruments are expected to bring us crucial information for the understanding of solar flares,” Kaufmann said.
The radio telescopes will be used to study the energy conversion and production mechanisms behind solar flares. “Even though it’s possible today to see rich detailed images of the spectacular mass ejections of solar flares, the physical phenomenon that causes all these manifestations is unknown,” he explained.
Aside from scientific relevance, Kaufmann noted that the study of the energetic mechanism of solar flares is important because of their byproducts, which impact the Earth by altering the so-called “space weather.”
“Even though we have no details about the physics of solar flares, they definitely have a strong impact on Earth’s climate. These explosions liberate immense quantities of energy that interact with interplanetary space and Earth,” he said.
Flares and Effects
According to Válio, the two radio telescopes will have the role of complementing the other instruments at CASLEO—with 200-400 gigahertz frequencies—installed 60 meters away in El Leoncito, and instruments in the United States that operate at frequencies lower than 20 gigahertz. The set of measurements will offer a complete picture of solar activity from the microwave level to the sub-millimeter level.
“The two new radio telescopes observe the entire solar disc at a high temporal resolution of 10 milliseconds, offering large quantities of data in terms of time. When all the calibrations are finished, the instruments will practically operate remotely, observing the Sun daily and placing the data on the internet,” she explained.
The radio telescopes cost 165,000 Euros, and installation was budgeted at US $25,000. Even though the cost is not high for instruments of this type, they have not been built due to the technological developments necessary to manufacture their receptors.
“Another factor that makes these instruments exclusive, aside from the frequencies at which they operate, is the capacity to measure polarization. The emission of energy from the Sun is thermal and not polarized. But an explosion involves highly accelerated electrons that spiral around magnetic lines with a preferential direction—making the emissions polarized,” said Válio.
She says that with polarization, it is possible to distinguish solar flares—even the very small ones—from atmospheric effects. “We will be able to investigate phenomena that will give us information about how the electrons are injected in the magnetic field of the flare,” she said.
Source: WebSite Agência FAPESP - http://agencia.fapesp.br/en/