Browsing by Title

Sort by: Order: Results:

  • Sporadic Variations in Wolf-Rayet Stars 
    Shylaja, B. S (International Astronomical Union, 1991)
    Many Wolf-Rayat stars display variations which are observable either spectroscopically or photometrically or both. These are not exclusively associated with binery systems. A study is made of the sporadic events in the ...
  • Sporadic-E associated with the Leonid meteor shower event of November 1998 over low and equatorial latitudes 
    Chandra, H; Sharma, S; Devasia, C. V; Subbarao, K. S. V; Sridharan, R; Sastri, J. H; Rao, J. V. S. V (European Geosciences Union, 2001-01)
    Rapid radio soundings were made over Ahmedabad, a low latitude station during the period 16 20 November 1998 to study the sporadic-E layer associated with the Leonid shower activity using the KEL Aerospace digital ionosonde. ...
  • Spot activity in the RS CVn binary DM Ursae Majoris 
    Mekkaden, M. V; Raveendran, A. V; Rosario, M. J; Heckert, P. A (Royal Astronomical Society, 2009-04)
    We present extensive UBVRI photometry of the active RS CVn binary DM UMa obtained at two different observatories over 1988-2008. We find the light curve of the star to be highly variable. The long-term photometry shows no ...
  • Spot activity in the RS CVn binary HR 1099 
    Mekkaden, M. V; Raveendran, A. V; Mohin, S (Indian Academy of Sciences, 1982-03)
    UBV photometry of HR 1099 obtained during the 1979-80 and 1980-81 observing seasons is presented. An analysis of the available data shows that the brightness at the light curve maximum increases as the wave amplitude ...
  • Spot and filament rotation in a sigmoidal flare 
    Sundararaman, K; Ramesh, K. B; Selvendran, R (Astronomical Society of India, 2001)
    The role played by the rotation of the umbrae in a sunspot with respect to the H? filament in inducing magnetic shear for the sigmoidal brightening is reported in this paper. We carried out these studies by using photoheliogram ...
  • SPOT Modelling in the Rs-Canum System Wy-Cancri 
    Vivekananda Rao, P; Sarma, M. B. K (Astronomical Society of India, 1990)
  • Spot size of 17m-diameter MACE reflector in presence of surface inaccuracies 
    Koul, D. K; Koul, M. K; Tickoo, A. K; Bhat, C. L (Astronomical Society of India, 2002)
    The MACE (for Major Atmospheric Cerenkov Experiment), an imaging cerenkov telescope for gamma-ray astronomy investigations in the sub-TeV energy bracket, plans to use a 17 m-diameter high quality reflecter mounted with a ...
  • Spread-F at Kodaikanal 
    Sastri, J. H; Murthy, B. S (European Geophysical Society, 1975-06)
    Quarter-hourly ionograms of Kodaikanal for the period January 1968 to December 1969 have been examined for occurrence of Spread-F. Spread-F occurrence as a feature on ionograms is more or less a regular nocturnal event ...
  • Squeezing of a coupled state of two spinors 
    Devi, A. R. U; Mallesh, K. S; Sbaih, M. A. A; Nalini, K. B; Ramachandran, G (Institute of Physics Publishing Ltd., 2003-05-16)
    The notion of spin squeezing involves a reduction in the uncertainty of a component of the spin vector vecS below a certain limit. This aspect has been studied earlier (Mallesh et al 2000a <A article="0305-4470/33/4/310">J. ...
  • SS 433: results of a recent multiwavelength campaign 
    Chakrabarti, S. K; Anandarao, B. G; Pal, S; Mondal, S; Nandi, A; Bhattacharyya, A; Mandal, S; Sagar, R; Pandey, J. C; Pati, A. K; Saha, S. K (Royal Astronomical Society, 2005-09)
    We conducted a multiwavelength campaign in 2002 September-October, to observe SS 433. We used the Giant Meter Radio Telescope for radio observations, the Physical Research Laboratory Infrared Telescope at Mt Abu for infrared ...
  • Stability of collinear equilibrium points in the generalised photogravitational elliptic restricted three-body problem 
    Sahoo, S. K; Ishwar, B (Astronomical Society of India, 2000)
    We have examined stability of collinear equilibrium points in the generalised photogravitational elliptic restricted three body problem. The problem is generalised in the sense that the smaller primary is considered as an ...
  • Stability of cool flux tubes in the solar chromosphere Linear analysis 
    Hasan, S. S; Kneer, F (EDP Sciences, 1986-04)
    The linear stability of cool flux tubes in the solar chromosphere which are initially in radiative equilibrium is examined. Owing to the presence of carbon monoxide, there exists a narrow region near the temperature minimum ...
  • Stability of cool flux tubes in the solar chromosphere. II - Non-linear dynamical behaviour 
    Hasan, S. S; Kneer, F (The European Southern Observatory, 1990-06)
    A single vertical cool flux tube in the solar chromosphere is focused upon for stability studies. The analysis of a previous study by Hasan and Kneer (1986) is extended to the nonlinear regime with a view to examining the ...
  • The Stability of Fiber Spectrographs in the Faint-source Regime 
    Bundy, Kevin; Law, David; MacDonald, Nick; Westfall, Kyle B.; Sivarani, T; Divakar, Devika; Bershady, Matthew; Gu, Meng; Yan, Renbin; Roy, Namrata; Poppett, Claire; Drory, Niv (American Astronomical Society, 2022-09-01)
    The use of optical fibers in astronomical instrumentation offers high-multiplex and light-gathering flexibility. However, with most previous fiber spectrographs optimized for large fields of view on modest-aperture telescopes, ...
  • Stability of galaxies across morphological sequence 
    Aditya, K (Oxford University Press on behalf of Royal Astronomical Society, 2023-06)
    We investigate the stability of nearby disc galaxies and galaxies at redshift (z) equal to 4.5. We explore the connection between the stability parameter (QRW), star formation rate (SFR), gas fraction (f Gas), and the ...
  • Stability of supermassive, neutrino dominated objects 
    Sivaram, C (World Scientific, 1995)
  • Stability of triangular points in the generalised photogravitational restricted three body problem 
    Singh, J; Ishwar, B (Astronomical Society of India, 1999)
    We study the effect of oblateness and radiation pressure forces of the primaries on the location and the stability of the triagular points in the restricted three body problem. We observe that the equations of motion and ...
  • Star clusters in the magellanic clouds II. age-dating, classification, and spatio-temporal distribution of the SMC clusters 
    Nayak, P. K; Subramaniam, A; Choudhury, S; Sagar, R (EDP Sciences, 2018-08)
    Aims. We aim to estimate the age and reddening parameters of already identified star clusters within the Small Magellanic Cloud (SMC) in a consistent way using available photometric data, classify them based on their mass ...
  • Star clusters in the magellanic clouds-1: parameterisation and classification of 1072 clusters in the LMC 
    Nayak, P. K; Subramaniam, A; Choudhury, S; Indu, G; Sagar, R (Oxford University Press on behalf of the Royal Astronomical Society, 2016-12-01)
    We have introduced a semi-automated quantitative method to estimate the age and reddening of 1072 star clusters in the Large Magellanic Cloud (LMC) using the Optical Gravitational Lensing Experiment III survey data. This ...
  • Star formation : circumstellar environment around Young Stellar Objects 
    Manoj, P (Astronomical Society of India, 2005-09)
    In this thesis we have undertaken a detailed study of the evolution of young circumstellar disks from the early pre-main sequence phase to the main sequence phase. We have used several observational diagnostics of the disks ...

Search DSpace

Browse

My Account