Date of Award
Master of Science in Applied Physics - (M.S.)
Dale E. Gary
Gregory D. Fleishman
The annular solar eclipse occurred on May 21, 2012 is studied using the radio data from the Jansky Very Large Array (JVLA), Sorrocco, Mexico. The eclipse is observed in the solar minimum activity period of solar cycle 24. The centimeter wavelength observation of the Sun's surface during the solar eclipse helps in determining the spatially well resolved features not obtained by the man made advanced technology. Even though, the activity on the Sun is observed to be low in the period of eclipse, the study provides a good opportunity to understand the quiet Sun features in the regions occulted by the Moon.
Rather than observing the Sun during the eclipse as a whole map of the entire field of view, differential technique is used to map strips of the field of view covered and obscured by the Moon's limb. This study is an attempt to understand the emission mechanism in the active region structures and the quiet Sun regions by realizing the change in the intensity levels of the observation than the intensity itself. During this work, it is discovered at least one anomaly in the data, called delay clunking, which reduces the frequency resolution to 125 MHz in 16 frequencies over the 2-4 GHz band. At the selected frequency of 2.56 GHz, the peak brightness temperature corresponding to both the active regions observed show 90% increase over the quiet Sun region value.
Even though the bright source like feature in the synthesis map does not show much variations in its size, it shows intensity enhancement at the peak occultation than the regions (quiet Sun) where the Moon is away from the active region. The correlation of the radio maps with the Solar Dynamo Observatory (SDO) show a good response to further study the JVLA data with a recheck in the calibration and with a higher frequency resolution.
Shaik, Shaheda Begum, "Solar eclipse observation on may 21, 2012 from JVLA" (2013). Theses. 179.