Browsing by Title

Sort by: Order: Results:

  • On the line profile changes observed during the X2.2 class flare in the active region NOAA 11158 
    Bayanna, A. R; Kumar, B; Venkatakrishnan, P; Mathew, S. K; Ravindra, B; Mathur, S; Garcia, R. A (IOP Publishing, 2014-02)
    The solar active region NOAA 11158 produced a series of flares during its passage through the solar disk. The first major flare (of class X2.2) of the current solar cycle occurred in this active region on 2011 February 15 ...
  • On the line ratio diagnostics for NeV, MgV, SiVII and Mg VII solar ions 
    Dwivedi, B. N; Mohan, Anita; Raju, P. K (Elsevier, 1997)
    We present NeV/MgV and MgVII/SiVII theoretical line intensity ratios as a function of electron density and temperature for physical conditions within the solar chromosphere-corona transition region. The electron pressure ...
  • On the Location of Footpoints of Sub-Arc Magnetic Structures in the Quiet Solar Photosphere 
    Sivaraman, K. R; Bagare, S. P; November, L. J (International Astronomical Union, 1990)
  • On the location of Solar Active Longitudes 
    Shelke, R. N; Verma, V. K (Astronomical Society of India, 1985-03)
    The longitudinal distributions of sudden ionospheric disturbances producing active regions with high flare activity and/or with at least one high energy flare particle event (PCA or GLE) have been examined. These active ...
  • On the long-cycle variability of the Algol OGLE-LMC-DPV-065 and its stellar, orbital, and disc parameters 
    Mennickent, R. E; Cabezas, M; Djurasevic, G; Rivinius, T; Hadrava, P; Poleski, R; Soszynski, I; Celedon, L; Astudillo-Defru, N; Raj, A; Fernandez-Trincado, J. G; Schmidtobreick, L; Tappert, C; Neustroev, V; Porritt, I (Oxford University Press on behalf of the Royal Astronomical Society, 2019-08)
    OGLE-LMC-DPV-065 is an interacting binary whose double-hump long photometric cycle remains hitherto unexplained. We analyze photometric time series available in archive data sets spanning 124 yr and present the analysis ...
  • On the magnitude variations of comet Swift-Tuttle (1992t) 
    Padalia, T. D; Gupta, S. K; Chaubey, U. S; Srivastava, R. K (Astronomical Society of India, 1995)
    The standard UBV magnitudes of the head of comet Swift-Tuttle(1992t)during four nights in December 1992, are estimated using our photoelectric observations. The overall brightness variations in the comet are discussed.
  • On the mass-radius relation for neutron stars 
    Abhyankar, K. D (Astronomical Society of India, 1991)
    The classical equation of state for a nonrelativistically degenerate gas containing free fermions gives an upper limit to the radius of a neutron star while the Schwarzschild radius gives the lower limit. The lower mass ...
  • On the Maxwellian alternative to the galactic dark matter problem 
    Sivaram, C (European Southern Observatory, 1993-08)
    Recently a new type of gravitational coupling due to a gravo-inductive force field generated by mass currents was introduced to account for constant rotation velocities at large distances from galactic cores. It is pointed ...
  • On the method of estimating emission altitude from relativistic phase shift in pulsars 
    Gangadhara, R. T (The University of Chicago Press, 2005-08-01)
    The radiation by relativistic plasma particles is beamed in the direction of field-line tangents in the corotating frame, but in an inertial frame it is aberrated toward the direction of rotation. We have revised the ...
  • On the nature of compact components of radio sources at 327 MHz 
    Balasubramanian, V; Janardhan, P; Ananthakrishnan, S; Srivatsan, R (Astronomical Society of India, 1996)
    The interplanetary scintillation (IPS) survey of about 5000 radio sources carried out during 1992-93 with the Ooty Radio Telescope (ORT) at 327 MHz has resulted in the detection of compact components in about 2700 sources. ...
  • On the nature of propagating MHD waves in the solar atmosphere 
    Gupta, G. R (Indian Institute of Astrophysics, 2010-12)
  • On the nature of radiation from the nucleus of a CD galaxy A0779 
    Deshpande, M. R; Joshi, U. C (Astronomical Society of India, 1993)
    An attempt is made to detect synchrotron radiation from the nucleus of a CD galaxy A-0779 through polarization studies. We have detected a high degree of polarization (up to 9 percent in ultraviolet) with a bimodal ...
  • On the nature of response of dayside equatorial geomagnetic H-field to sudden magnetospheric compressions 
    Sastri, J. H; Yumoto, K; Rao, J. V. S. V; Subbiah, R (Elsevier, 2006-09)
    A step-like increase in the solar wind ram pressure causes a sudden compression of the magnetosphere which manifests as a sudden commencement (SC) in the geomagnetic field. SC manifests in two basic forms in the geomagnetic ...
  • On the nature of substorm-related transient electric field disturbances in the equatorial ionosphere 
    Sastri, J. H; Ramesh, K. B; Karunakaran, D (Elsevier, 1992-01)
    Results are presented of a study of h-prime F data derived from interval ionograms recorded on the night of August 29-30, 1957 at Kodaikanal (10 deg 14 min N, 77 deg 29 min E, geomag. lat. 0.6 deg N) during a geomagnetic ...
  • On the nature of the compact condensations at the centre of galaxies 
    Mitra, A (Astronomical Society of India, 2002)
    There are many observational evidences for the existence of massive compact condensations in the range 106 - 1010 M? at the core of various galaxies and in particular in the core of High Energy Gamma Ray emitting galaxies. ...
  • On the Neutrino Emissivity of Degenerate Strange Quark Matter 
    Datta, B; Raha, S; Sinha, B (World Scientific Publishing Company, 1988-10)
    We examine the neutrino emissivity of a system of degenerate three-component (u, d, s) strange quark matter using improved expressions for the quark chemical potentials in a self-consistent manner, and obtain tighter bounds ...
  • On the non-acceleration origin of the highest energy cosmic rays 
    Sivaram, C (University of Calgary, 1993)
    The Hawking radiation from primordial black holes in their near terminal stages of evaporation can produce ultra high energy (UHE) particles spontaneously. The contribution from such objects to the highest energy cosmic ...
  • On the observational behaviour of the highly polarized Type IIn supernova SN 2017hcc 
    Brajesh Kumar; Eswaraiah, C; Singh, A; Sahu, D. K; Anupama, G. C; Kawabata, K. S; Yamanaka, Masayuki; Otsubo, Ikki; Pandey, S. B; Nakaoka, Tatsuya; Kawabata, Miho; Aryan, Amar; Akitaya, Hiroshi (Oxford University Press on behalf of the Royal Astronomical Society, 2019-09)
    We present the results based on photometric (Swift UVOT), broad-band polarimetric (V and Rbands) and optical spectroscopic observations of the Type IIn supernova (SN) 2017hcc. Our study is supplemented with spectropolarimetric ...
  • On the occurrence and vertical movement of kink at Kodaikanal 
    Narayana Iyer, K; Rastogi, R. G (American Geophysical Union, 1974)
    The occurrence of ionospheric irregularities observed as sharp discontinuities (kinks) on the ionograms and moving upward with time at Kodaikanal have been studied for a period covering high, medium, and low solar activity ...
  • On the occurrence of AQDs at Kodaikanal 
    Sastri, J. H; Murthy, B. S (The Council of Scientific and Industrial Research, 1978-02)
    A study is made of the occurrence of 'abnormal quiet days' (AQDs) at Kodaikanal (10 deg 14 min N, 77 deg 28 min E; dip 3.5 deg N) using H-field data over a 26-yr period (1950-1975). The results show distinctive differences ...

Search DSpace

Browse

My Account