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Browsing IIAP Publications by Title

Browsing IIAP Publications by Title

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  • Javaraiah, J (Elsevier, 2013-09-01)
    Recently, we analyzed the combined Greenwich and Solar Optical Observing Network (SOON) sunspot group data during the period 1874-2011 and studied variations in the annual numbers of small, large and big sunspot groups. ...
  • Sukanya, N; Stalin, C. S; Joseph, P; Rakshit, S; Praveen, D; Damle, R (Indian Academy of Sciences, 2018-12)
    Flux variability is one of the defining characteristics of Seyfert galaxies, a class of active galactic nuclei (AGN). Although these variations are observed over a wide range of wavelengths, results on their flux variability ...
  • Sukanya, N; Stalin, C. S; Joseph, P; Rakshit, S; Praveen, D; Damle, R (Indian Academy of Sciences, 2018-12)
    Flux variability is one of the defining characteristics of Seyfert galaxies, a class of active galactic nuclei (AGN). Although these variations are observed over a wide range of wavelengths, results on their flux variability ...
  • Karak, B. B; Miesch, Mark (Cambridge University Press, 2018-02)
    We explore the cause of the solar cycle variabilities using a novel 3D Babcock– Leighton dynamo model. In this model, based on the toroidal flux at the base of the convection zone, bipolar magnetic regions (BMRs) are ...
  • Javaraiah, J (Springer, 2010)
    Using sunspot group data from Greenwich and from the Solar Optical Observation Network during 1879–2008, we find that the mean meridional motion of the observed spot groups varies considerably on a time scale of about 10–20 ...
  • Javaraiah, J; Bertello, L; Ulrich, R. K (Springer, 2005-12)
    The solar equatorial rotation rate, determined from sunspot group data during the period 1879 2004, decreased over the last century, whereas the level of activity has increased considerably. The latitude gradient term of ...
  • Javaraiah, J (Springer, 2011-06)
    Using the combined Greenwich (1874 – 1976) and Solar Optical Observatories Network (1977 – 2009) data on sunspot groups, we study the long-term variations in the mean daily rates of growth and decay of sunspot groups. ...
  • Priyal, M; Singh, J; Ravindra, B; Kameshwaran Rathina, Somasundaram (Springer, 2017-07)
    In our previous article (Priyal et al. in Solar Phys. 289, 127, 2014) we have discussed the details of observations and methodology adopted to analyze the Ca-K spectroheliograms obtained at the Kodaikanal Observatory (KO) ...
  • Javaraiah, J (EDP Sciences, 2010-01)
    Aims. We seek the long-term variations close to the length of a solar cycle in the mean meridional motion of sunspot groups (a proxy of the meridional plasma flow). Methods. Using the largest set of available reliable ...
  • Javaraiah, J (Elsevier B.V, 2015-01)
    The combined Greenwich and Solar Optical Observing Network (SOON) sunspot group data during 1874–2013 are analysed and studied the relatively long-term variations in the annual sums of the areas of sunspot groups in 0°–10°, ...
  • Javaraiah, J (Springer, 2003-01)
    Using Greenwich data (1879 1976) and SOON/NOAA data (1977 2002) on sunspot groups we found the following results: (i) The Sun's mean (over all the concerned cycles during 1879 1975) equatorial rotation rate (A) is significantly ...
  • Ramesh, R (Kluwer Academic Publishers, 1999-10)
    We report radio observations of enhanced emission associated with the extreme-ultraviolet (EUV) jets from polar coronal hole regions of the Sun, with the Gauribidanur radioheliograph (GRH). We have estimated the brightness ...
  • Sastri, J. H (American Geophysical Union, 1996-02)
    The effect of solar activity on the postsunset peak of F region vertical plasma drift at Kodaikanal (77°28'E, dip 3°N) is determined as a function of season and for two levels of magnetic activity using extensive HF phase ...
  • Gokhale, M. H; Hiremath, K. M (Elsevier, 1986)
    It is shown that if a thin, isolated and untwisted magnetic flux tube, consisting of a current-free core bounded by a thin current sheath, is in an ‘overall’ equilibrium in a stratified atmosphere, then there is, in general, ...
  • Sterken, C; Manfroid, J; Anton, K; Barzewski, A; Bibo, E; Bruch, A; Burger, M; Duerbeck, H. W; Duemmler, R; Heck, A; Hensberge, H; Hiesgen, M; Inklaar, F; Jorissen, A; Juettner, A; Kinkel, U; Zongli, L; Mekkaden, M. V; Ng, Y. K; Niarchos, P; Puttmann, M; Szeifert, T; Spiller, F; Vandijk, R; Vogt, N; Wanders, I (European Southern Observatory, 1993-11)
    In this paper we present the second catalogue of photometric data in the Stromgren system obtained during the period October 1986 - September 1990 in the framework of the Long-Term Photometry of Variables (LTPV)program at ...
  • Venkatakrishnan, P (Kluwer Academic Publishers, 1990-08)
    We demonstrate that magnetic tension vanishes at regions of large magnetic shear on the polarity inversion line. The characteristics of these tension-free fields depend on the density of the medium and, therefore, change ...
  • Saxena, A. K; Yeswanth, L (SPIE, 1990-12)
    This paper describes a method for testing a right angle prism, or any other optical component having a right angle, to subarcsecond accuracy. The method makes use of Haidinger fringes and is simple to use. Unlike autocollimation ...
  • Sawant, H. S; Neri, J. A. C. F; Fernandes, F. C. R; Cecatto, J. R; Sankararaman, M. R; Faria, C; Stephany, S; Rosa, R. R; Andrade, M. C; Alonso, E. M. B; Ludke, E; Subramanian, K. R; Ramesh, R; Sundararajan, M. S; Ananthakrishnan, S; Swarup, G; Boas, J. W. V; Botti, L. C. L; Moron, C. E; Saito, J. H (Elsevier B. V., 2003)
    We present the technical characteristics of a low-cost radio telescope for solar/non solar observations at decimetric (1200–1700 MHz) and centimetric (2700 and 5000 MHz) wavelengths known as Brazilian Decimetric Array ...
  • Ramesh, R (Cambridge University Press, 2005)
    Ground based radio imaging observations play an useful role in the study of mass ejections from the solar corona since they do not have the limitation of an occulter and both the disk/limb events can be detected early in ...
  • Ramesh, R; Sastry, Ch. V (Astronomical Society of the Pacific, 2005-12)
    We measured the degree of circular polarization of the thermal radiation from discrete structures in the solar corona at a frequency of 77 MHz and attempted to derive the magnetic field strength of these regions.

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