Science & Technology Current Affairs April 2016

Features of the GIRI System

• It is a 30 MHz radar system that will be engaged in meteor and space weather research in a comprehensive way.

• It consists of a rectangular antenna array of 160 two-element Yagi-antenna, arranged in a 20*8 matrix, 20 transmitter units, 6 digital receivers including data processing systems, a radar controller, and a host computer.

• Its primary objective is to carry out unattended observations towards studying the forcing from the sun like variation in solar flux, solar flare and magnetic storm on the ionospheric irregularities.

• It also seeks to study unattended observations from the underneath atmosphere (e.g., waves generated by weather phenomena) on the ionospheric irregularities.

• It will provide important information on the angular location of plasma irregularities during the onset phase and its relationship to background ionospheric state parameters and sunset terminator.

• Investigations made using this facility are expected to improve the skill in Equatorial Plasma Bubble (EPB) forecasting which is detrimental for satellite based navigation/communication applications.

Hubble Discovered Largest Sample of Monster Stars

• The astronomers using the NASA/ESA Hubble Space Telescope have identified nine monster stars as R136 with masses over 100 times that of our Sun in the star cluster located about 170000 light-years away.

• The detected stars are not only extremely massive, but also extremely bright. Together these nine stars outshine the Sun by a factor of 30 million.