Kodaikanal Observatory Bulletins (1905 - 1997 ): Recent submissions

  • Narrow Band Photometry in Emission Lines during the Total Solar Eclipse of October 24, 1995 
    Singh, J; Cowsik, R; Venkatakrishnan, P; Srinivasan, R; Chinnappan, V; Raju, K. P; Srikanth, R (Indian Institute of Astrophysics, Bangalore, 1997)
    To investigate the spatial variation of tempereture and density within coronal strucures, narrow band photometry in three coronal emission lines was done during this eclipse. The emission lines 6374 (FeX), 7892 (Fe XI) and ...
  • CCD Observations of the Total Solar Eclipse of October 24, 1995 
    Verma, V. K; Wahab Uddin; Gaur, V. P; Joshi, G. C; Bondal, K. R (Indian Institute of Astrophysics, Bangalore, 1997)
    The observations of the solar corona during the Total Solar Eclipse of October 24, 1995 were attempted in white light and in narrow band filters with peak wavelenghts centered at 5303 Armstrong (FeXIV) and at 6474 Armstrong ...
  • Ultra-low Spatial Resolution Photometry in Near-infrared to Detect the Solar Dust Ring 
    Singh, J; Cowsik, R; Raju, K. P; Mohin, S; Ravi, K (Indian Institute of Astrophysics, Bangalore, 1997)
    There are conflicting reports about the existence of the dust ring around the Sun. An experiment to detect the solar dust ring was performed by IIA group during the total solar eclipse of Oct. 24, 1995. A near-infrared ...
  • No signature of Circum-Solar Dust Ring up to 5R. from Optical Polarization and Near IR Observations of 24 October 1995 Total Solar Eclipse 
    Prasad, C. D; Ambastha, A. K (Indian Institute of Astrophysics, Bangalore, 1997)
    A circum-solar dust ring, consisting of interplanetary particles, is believed to be situated at 4R., and temporarily variable in anti-phase with the solar activity cycle. The signature of such a ring should be observable ...
  • A Study of Inner Solar Corona during Total Solar Eclipse of October 24, 1995 
    Saxena, A. K; Cowsik, R; Lancelot, J. P; Samson, J. P. A; Bagare, S. P; Ismail, R (Indian Institute of Astrophysics, Bangalore, 1997)
    To study the inner corona during the total solar eclipse of October 24, 1995, an experiment was setup at Kalpi, the second location of the two IIA camps. Continuous broad record at regular interval at 40ms (TV rate) using ...
  • Compton Broadening Due To Electron Scattering 
    Peraiah, A; Srinivasa Rao, M (Indian Institute of Astrophysics, Bangalore, 1993)
    We have investigated the effects of Compton broadening due to electron scattering in the hot stellar atmosphere, quasars, AGN's etc. We considered a purely electron scattering media. The Compton effect scattering function ...
  • Stellar Winds in O and B Type Stars: Hydrogen Atmosphere 
    Peraiah, A; Varghese, B. A (Indian Institute of Astrophysics, Bangalore, 1993)
    We present the results of calculations of radiation driven stellar winds O-B stars. The equations of conservation of mass and momentum are solved self consistently with the equation of line transfer. The influence of ...
  • Telescope drive requirements and design of a Microcontroller based drive and display system 
    Chinnappan, V (Indian Institute of Astrophysics, Bangalore, 1993)
    Optical telescope is a precision instrument which gives images of stars and galaxies when the telescope is pointed towards them. To design a good telescope drive, the requirements of a good telescope is to be well defined. ...
  • Laser Damage Threshold studies on Ion Plated Perylene Thin Films 
    Subbarayan, A; Balasubramanian, C; Narayandass, Sa. K (Indian Institute of Astrophysics, Bangalore, 1991)
    Perylene thin films were deposited on cleaned glass substrates by ion plating technique in r.f.glow (10 MHz) sustained by argon gas of pressure 0.399 Pa. Laser-induced damage threshold of these thin films has been studied ...
  • Optical Phase Conjugation in Iodine Solutions 
    Vijaya, R; Murti, Y. V. G. S; Sundararajan, G; Prasada Rao, T. A (Indian Institute of Astrophysics, Bangalore, 1991)
    Results of experimental investigations on the optical phase conjugation in iodine solutions are reported in this paper. Degenerate four wave mixing is performed at two different wavelengths - one within the resonant regime ...
  • Use of Lasers in Satellite to Earth Communication Link 
    Sundar Kumar Iyer, S; Mukunda Rao, M (Indian Institute of Astrophysics, Bangalore, 1991)
    With the growing demand of communication requirement all over the world, there is no way out to go in for higher carrier frequencies. A far sighted move be to in for laser communication links in areas like earth to satellite ...
  • Rib Waveguide polarizer in GaAs/AlGaAs 
    Gupta, V. L; Sharma, E. K; Tripathi, K. N; Srivastava, G. P (Indian Institute of Astrophysics, Bangalore, 1991)
    Metal clad wave guides have an extremely large differential attenuation of TE and TM states of polarization and can be used to design efficient intergrated polarizers. Described here is a AlGaAs rib wave guide polarizer ...
  • Fast Photometry Uisng CCD 
    Srinivasan, R; Muralishankar, S; Rajamohan, R (Indian Institute of Astrophysics, Bangalore, 1991)
    Observations of certain objects which exhibit fast changes in their light output seems to be of great interest in optical astronomy. Important informations can be obtained on their internal structures of the stars through ...
  • Intensified CCD Camera Based Remote Guiding Unit for VBT and Observation of Speckles with ICCD 
    Chinnappan, V; Saha, S. K; Faseehana (Indian Institute of Astrophysics, Bangalore, 1991)
    For successful observations in any telescope, guiding becomes important. On 2.34 m Telescope at Vainu Bappu Observatory, Kavalur, a remote guiding system is assembled using Intensified CCD camera and a PC based image ...
  • Increment Threshold as a Function of Background Illumination: Contribution of cellular adaptation 
    Gupta, B. D (Indian Institute of Astrophysics, Bangalore, 1991)
    In the present communication we have studied the contribution of cellular adaptation in increasing the photoreceptor increment threshold as a function of background intensity in intact eye and isolated retina. In intact ...
  • A Sol-Gel Derived AR coating on Ophthalmic Lenses in the Visible Region 
    Biswas, P. K; Atta, A. K; Ganguli, D (Indian Institute of Astrophysics, Bangalore, 1991)
    Deposition of antireflective coating in the visible region by the sol-gel spinning technique has been described in this communication. A 2-layer design, centred at 550 nm, was used. The design can be denoted as Glass/H/L/Air ...
  • Thickness Dependence of the Optical properties of Vacuum Evaporated YF3 Thin Films 
    Satyamoorthy, R; Narayandass, Sa. K; Balasubramanian, C; Mangalaraj, D (Indian Institute of Astrophysics, Bangalore, 1991)
    Rare earth oxides and fluorides are well known for their refractory nature and chemical stability and so they find considerable application in electronic and optical devices. The present investigation deals with the optical ...
  • Application of Spectroscopic Ellipsometry to Study the Effect of Annealing on Cadmium Sulphide Thin Films 
    Mathew, Sunny; Vijayakumar, K. P (Indian Institute of Astrophysics, Bangalore, 1991)
    Multiple angle spectroscopic ellipsometery (SE) has been used to study the variation in the layer structure due to annealing of CdS thin films prepared by spray pyrolysis technique. The samples were studied using visible ...
  • Fabrication of Gradient-Index lens by Ion-Exchange in Glass 
    Masalkar, P. J; Rao, V. V; Sirohi, R. S (Indian Institute of Astrophysics, Bangalore, 1991)
    GRIN lenses have been fabricated using Ag/sup+/ < -- > Na/sup+/ ion-exchange in glass. The fabrication process and characterization of GRIN lenses are discussed. The refractive index profile was studied on the Mach-Zehnder ...
  • Development of Polishing Procedure for Producing Highly Specularly Reflecting Surface for Sun Shield Panels of INSAT II TS VHRR Radiant Cooler 
    Saxena, A. K (Indian Institute of Astrophysics, Bangalore, 1991)
    VIRR Radient Cooler used for cooling of infrared detector of VHRR instrument onboard INDIAN NATIONAL SATELLITE [INSAT II] is being developed at Thermal Systems Division of ISAC/ISRO, Bangalore. This development work is ...

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