Kodaikanal Observatory Bulletins (1905 - 1997 ): Recent submissions

  • An Aspheric Grin Ray Trace Program for Thermal Analysis of Optical Systems 
    Sharma, D. K; Shyam, D; Sujatha, G (Indian Institute of Astrophysics, Bangalore, 1991)
    In this communication we describe a program which can ray trace through systems bounded by spherical/ aspheric surfaces together with the option to trace through media having graded index profile (GRIN) for one or more ...
  • Helmholtz Resonance Cell for Gas Phase Photoacoustic Studies 
    Ajith Prasad, K. C; Nampoori, V. P. N; Vallabhan, C. P. G (Indian Institute of Astrophysics, Bangalore, 1991)
    The design and frabication of a Helmholtz type gas phase photoacoustic cell are described. The cell which incorporates a miniature microphone (Knowles B.T.1759) along with a matching pre-amplifier is very sensitive and can ...
  • On Luminescent Properties of SrS: Sm Phosphor Using Nitrogen Laser Excitation 
    Baby, Thomas; Nampoori, V. P. N (Indian Institute of Astrophysics, Bangalore, 1991)
    The fluorescence emission spectrum of SrS: Sm phosphor in the visible region is recorded. It consists of three groups of emission bands which are well resolved into discrete lines. On the basis of the crystal field theory, ...
  • Comparison of Experimental and Theoretical Study of Diffuse Reflectance of Highly Scattering Particulate Systems 
    Shah, H. S; Adroja, D. G; Vaidya, D. B (Indian Institute of Astrophysics, Bangalore, 1991)
    Diffuse reflectance of titanium dioxide pigment dispersion is measured in visible region for wavelengths 400(20)700 nm. Kubelka-Munk absorption and scattering coefficients are determined using two constant K-M theory. ...
  • Asymptotic Values of Some Scattering Parameters from Mie Theory 
    Shah, G. A (Indian Institute of Astrophysics, Bangalore, 1991)
    The scattering parameters such as extinction efficiency, albedo, asymmetry parameter, etc, have been studied on the basis of the Mie theory of scattering of electromagnetic radiation by a sphere as well as the classical ...
  • Some Aspects of Rayleigh and Mie Scattering in the Atmosphere Over Pune 
    Devara, P. C. S; Raj, P. E (Indian Institute of Astrophysics, Bangalore, 1991)
    Computations of aerosol mixing ratio [( Na + Nm)/Nm] have been made using the aerosol number density (Na) estimated from the laser radar (lidar) observations carried out at the IITM, Pune and air molecular number density ...
  • Multipole structure of the heliomagnetic field and northsouth asymmetry in the heliospheric current sheet 
    Girish, T. E; Prabhakaran Nayar, S. R (Indian Institute of Astrophysics, Bangalore, 1988)
    North-South asymmetry in the heliospheric current sheet (HCS) defined as the difference in the maximum helioatitudinal extension of the HCS in the northern and southern heliospheres, can be classified into two different ...
  • Observations of the brightness temperature distribution of the quiet solar corona at decametric wavelengths 
    Sastry, Ch. V (Indian Institute of Astrophysics, Bangalore, 1988)
    The brightness temperature distribution of the quiet solar corona at a wavelength of 8.9 Meters is measured with two types of radio telescopes: (1) A “ T ” type array with a resolution of 26’x38’ and (2) A fan beam ...
  • Optical observations of the Sun 
    Bhatnagar, A (Indian Institute of Astrophysics, Bangalore, 1988)
  • Possibility of occurrence of solar proton flares in relation to other phenomena 
    Uddin, W; Pande, M. C; Verma, V. K (Indian Institute of Astrophysics, Bangalore, 1988)
    In the present investigation we have studied the relation between solar proton flares and associated optical, radio and x-ray events. It is found that optical flares are usually associated with large optical flares in ...
  • Diffuse echo bursts at 34.5 MHz 
    Subramanian, K. R (Indian Institute of Astrophysics, Bangalore, 1988)
    The solar radio bursts during their propagation towards the earth are refracted, scattered, reflected and absorbed. The combination of these effects play a role in determining the source size, position, brightness temperature ...
  • On the periodicity of solar great hard X-ray bursts, energic solar radio bursts and sunspot data 
    Verma, V. K; Joshi, G. C (Indian Institute of Astrophysics, Bangalore, 1988)
    In the last solar maximum period (cycle 21) the 152-158 day periodicity was found in the occurrence rate of solar flares through solar gamma ray, microwave, soft X-ray, hard X-ray and H-alpha flares. In the present, brief ...
  • Electron impact polarization of resonance lines from Li-like ions 
    Chandra, Suresh (Indian Institute of Astrophysics, Bangalore, 1988)
  • Two ribbon flare on April 3, 1980 
    Jain, Rajmal (Indian Institute of Astrophysics, Bangalore, 1988)
    H alpha observations of a two ribbon (TR) flare which were associated with exceptionally high microwave (MW) and hard X-ray emissions are presented and discussed. The good spatial and temporal resolution of the H alpha ...
  • Reduction of Photoheliograms by IBM-PC controlled digitizer 
    Ambastha, A (Indian Institute of Astrophysics, Bangalore, 1988)
    A method is described here to determine heliographic coordinates of sunspots on a photoheliogram using an IBM-PC controlled digitizer. Sunspot proper-motions and buildup of magnetic energy in solar active regions may be ...
  • Peculiar abundances in Solar particle emissions 
    Vahia, M. N (Indian Institute of Astrophysics, Bangalore, 1988)
    In this paper we attempt to show that currently available data on solar flare particle abundances allows studies of abundance and enchancement patterns. In particular we show that solar particles originate from regions of ...
  • Solar X-ray bursts 
    Rausaria, R. R (Indian Institute of Astrophysics, Bangalore, 1988)
    The experimental results of X-ray bursts about spectral characteristics, spatial distribution and directivity measurements carried out with PVO/ISEE-3 spacecraft imaging instruments of HXIS and Hard X-ray burst spectrometers ...
  • Radio emission from the Solar Corona due to shock waves 
    Thejappa, G (Indian Institute of Astrophysics, Bangalore, 1988)
    The slowly drifting solar type II radio bursts are believed to be due to the flare associated shock waves propagating radially outward in the corona. The main observational characteristics of these bursts show that the ...
  • A new technique to study the variability of the Sun 
    Singh, J (Indian Institute of Astrophysics, Bangalore, 1988)
    A method has been developed to take the high resolution spectra in ionized calcium K line at different latitudes and integrated over visible 180/sup0/ longitude. These spectra have been analysed to study the variability ...
  • Long term periodicities of Geomagnetic reversals and stability of ancient Galactic motions of the solar system 
    Negi, J. G (Indian Institute of Astrophysics, Bangalore, 1988)
    Paleomagnetic records can be a rich source of empirical data in characteristic time scales of tremendous interest to solar astronomers and verifiable theories on the earth’s evolution in its galactic environment. The record ...

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