Accession Number : ADA259983


Title :   Granulation In and Out of Magnetic Region


Corporate Author : PHILLIPS LAB HANSCOM AFB MA


Personal Author(s) : Koutchmy, Serge


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a259983.pdf


Report Date : 25 Jun 1988


Pagination or Media Count : 21


Abstract : We performed an analysis of several granulation pictures obtained in both a quiet region and a plage or magnetic region. Filtergrams of ultra-narrow passband and free of line-blocking were obtained with the Sac Peak Vacuum Telescope with an average 0.5 arcsec spatial resolution. Results of a statistical comparative study are presented: amplitude spectra, RMS and histograms of intensity fluctuations. The precise location of a large sample of magnetic field structures identified with MgI b sub 1 + 0.4A filtergrams was analyzed; 20.4% of these structures overlap or are inserted in granules, which give a natural explanation of the high value of the RMS in the magnetic region. We used selected very high spatial resolution broad-band short exposure time pictures to show crinkles-type structures at the center of granules that we identify with the abnormal granulation and 'magnetic' granules.


Descriptors :   *SOLAR PHYSICS , REPRINTS , MAGNETIC FIELDS , SPECTRA , SOLAR ACTIVITY , AMPLITUDE , TELESCOPES , SOLAR SPECTRUM , CONVECTION(ATMOSPHERIC) , SUNSPOTS , PHOTOSPHERE , SUN , GRANULES


Subject Categories : Astrophysics


Distribution Statement : APPROVED FOR PUBLIC RELEASE