Solar dynamics imaging system a back-end instrument for the proposed NLST

The Solar Dynamics Imaging System (SDIS) will be one of the focal plane instruments operated at the National Large Solar Telescope (NLST). The prime objective of the instrument is to obtain high spatial and temporal resolution images of the region of interest on the Sun in the wavelength range from 390 nm to 900 nm. The SDIS provides filtergrams using broad-band filters while preserving the Strehl ratio provided by the telescope. Furthermore, the SDIS is expected to provide observations that allow image reconstruction to extract wave front information and achieve a homogenous image quality over the entire FOV.     

A source for the Reissner-Nordstrøm metric

An exact solution of the coupled Einstein-Maxwell equations representing the gravitational field in the interior of a sphere of charged incoherent matter in equilibrium is obtained which is a charged analogue of the static perfect fluid sphere solution with spheroidal 3-space obtained by Vaidya & Tikekar.     

Geomagnetic disturbances associated with disappearing solar filaments

To gain an insight into the origin of enhanced geomagnetic activity that is recently reported to follow the disparition brusque (DB) of quiescent solar filaments, a study is made of the interplanetary plasma and magnetic field data at 1 AU, in relation to DBs over the period January 1967 through March 1978. The investigation revealed that the minor (Ap 30) and major (Ap 50) geomagnetic disturbances that manifested within 8 days of DBs, almost invariably occurred (in 28 out of the 30 events studied) in association with the passage at Earth of high-speed streams in the solar wind. A majority of the streams (19 out of the 28 streams) exhibited a 27-day recurrence pattern and, thus, the associated enhancement in geomagnetic activity (and apparently followed DBs). The date of transit of the high-speed stream at Earth seems to control the delay time of the geomagnetic disturbance, rather than the size of the filament. A systematic spatial relationship between DB's and the potential solar sources of the high-speed streams (coronal holes and flares) does not appear to be present. The results point out the relevance and a prominent role of recurrent and transient high-speed structures in the solar wind in the enhancement of geomagnetic activity that accompagnies DBs.     

Radio Interferometric Observations of the Sun Using Commercial Dish TV Antennas

This memoir is a summary of my early childhood, education, and research career at the Naval Research Laboratory (NRL) in Washington, DC. I describe my early interest in astronomy and how I wound up working in the fields of solar physics and X-ray-UV spectroscopy of high temperature plasmas. I describe some of my home life and other interests, my education at the University of Pittsburgh, and the various projects and management activities that I have been fortunate to work on at NRL. I have been blessed with being able to work at a first-class research laboratory populated by outstanding scientists. I am particularly blessed to have worked with my many friends and colleagues in the NRL Space Science Division. Perhaps I am most blessed by having had wonderful parents that gave me the interests I have in life and the passion to pursue them, and an outstanding wife that has been my partner through good and bad times for over 50 years. I am now retired but for three years I was a participant in the NRL Voluntary Emeritus Program (VEP). However, this memoir is a personal account, and not work done as a VEP.