Articles written in Journal of Astrophysics and Astronomy

    • Mid-term periodicities and heliospheric modulation of coronal index and solar flare index during solar cycles 22–23


      More Details Abstract Fulltext PDF

      We applied fast Fourier transform techniques and Morlet wavelet transform on the time series data of coronal index, solar flare index, and galactic cosmic ray, for the period 1986–2008, in order to investigate the long- and mid-term periodicities including the Rieger ($\sim$130 to $\sim$190 days), quasi-period ($\sim$200 to $\sim$374 days), and quasi-biennial periodicities ($\sim$1.20 to $\sim$3.27 years) during the combined solar cycles 22–23. We emphasize the fact that a lesser number of periodicities are found in the range of low frequencies, while the higher frequencies show a greater number of periodicities. The rotation rates at the base of convection zone have periods for coronal index of $\sim$1.43 years and for solar flare index of $\sim$1.41 year, and galactic cosmic ray, $\sim$1.35 year, during combined solar cycles 22–23. In relation to these two solar parameters (coronal index and solar flare index), for the solar cycles 22–23, we found that galactic cosmic ray modulation at mid cut-offrigidity (${\rm Rc} = 2.43$GV) is anti-correlated with time-lag of few months.

  • Journal of Astrophysics and Astronomy | News

    • Continuous Article Publication

      Posted on January 27, 2016

      Since January 2016, the Journal of Astrophysics and Astronomy has moved to Continuous Article Publishing (CAP) mode. This means that each accepted article is being published immediately online with DOI and article citation ID with starting page number 1. Articles are also visible in Web of Science immediately. All these have helped shorten the publication time and have improved the visibility of the articles.

    • Editorial Note on Continuous Article Publication

      Posted on July 25, 2019

      Click here for Editorial Note on CAP Mode

© 2021-2022 Indian Academy of Sciences, Bengaluru.