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  • On the orbital periods of the eclipsing binaries CM Lacertae, AB Andromedae and YY Eridani 
    Panchatsaram, T; Abhyankar, K. D (Astronomical Society of India, 1981-09)
    A study of all the available photoelectric times of minima of CM Lac, AB And and YY Eri does not reveal any changes in their orbital periods.
  • On the orientation of the pulsar space velocity vector relative to the spin axis 
    Kochhar, R. K (Nature Publishing Group, 1977-05)
    It is noted that the angle between the space velocity vector and the spin axis projected on the plane of the sky has a value close to zero deg for three pulsars, close to 90 deg for six others, and between zero and 90 deg ...
  • On the origin of core radio emissions from black hole sources in the realm of relativistic shocked accretion flow 
    Das, Santabrata; Nandi, Anuj; Stalin, C. S; Rakshit, Suvendu; Dihingia, Indu Kalpa; Singh, Swapnil; Aktar, Ramiz; Mitra, Samik (Oxford University Press on behalf of Royal Astronomical Society, 2022-08)
    We study the relativistic, inviscid, advective accretion flow around the black holes and investigate a key feature of the accretion flow, namely the shock waves. We observe that the shock-induced accretion solutions are ...
  • On the Origin of Gamma-Ray Flares from Bright Fermi Blazars 
    Paliya, Vaidehi S; Böttcher, M; Gurwell, Mark; Stalin, C. S (IOP Publishing, 2021-12)
    The origin of γ-ray flares observed from blazars is one of the major mysteries in jet physics. We have attempted to address this problem following a novel spectral energy distribution (SED) fitting technique that explored ...
  • On the origin of highest energy cosmic rays 
    Sigl, G; Schramm, D. N; Bhattacharjee, P (Elsevier, 1994-09)
    In this paper we show that the conventional diffusive shock acceleration mechanism for cosmic rays associated with relativistic astrophysical shocks in active galactic nuclei (AGNs) has severe difficulties to explain the ...
  • On the oscillator strength and the dissociation energy of CN molecules 
    Sinha, K; Tripathi, B. M (Astronomical Society of Indian, 1986-03)
    Equivalent widths of the CN red system in the solar spectrum are determined and compared with previous observational data in order to evaluate various published values for oscillator strength and dissociation energy. The ...
  • On the Oscillator strengths of the Phillips bands 
    Sinha, K (Astronomical Society of India, 1984-03)
    The recently published values of oscillator strengths for the Phillips bands were checked with those obtainable from the solar spectrum. The results of (1982) Erman et al. based on the assumption of a varying electronic ...
  • On the Out of Phase Appearance of Large-Scale Diffuse Magnetic Field of the Sun with Respect to Sunspots 
    Dikpati, M; Choudhuri, A. R (Kluwer Academic Publishers, 1996-03)
    We assume the large-scale diffuse magnetic field of the Sun to originate from the poloidal component of a dynamo operating at the base of the convection zone, whereas the sunspots are due to the toroidal component. The ...
  • On the p-mode Asymmetry between Velocity and Intensity from the GONG+ Data 
    Tripathy, S. C; Jain, K; Hill, F; Toner, C. G (Astronomical Society of India, 2003)
    We have analyzed the local acoustic spectra of small regions over the solar surface at different locations from disk center to limb via the technique of ring diagrams. The analysis suggest that the frequency shifts between ...
  • On the parallax of α Herculis 
    Jacob, W. S (Royal Astronomical Society, 1853-06)
  • On the performance of a dual-beam polarimeter at Kodaikanal tower telescope 
    Nagaraju, K; Sankarasubramanian, K; Rangarajan, K. E; Ramesh, K. B; Singh, J; Devendran, P; Hariharan (Astronomical Society of India, 2008-09)
    Calibration and characterization of a dual-beam polarimeter installed at Kodaikanal Tower Telescope (KTT) for spectropolarimetric observations are presented in this paper. It was found that a slit width of 48 μ is optimum ...
  • On the Period of Delta Ceti 
    Mohan, Vijay (Astronomical Society of India, 1979-12)
    A period analysis of delts Ceti has been carried out. It has been found that the period of delta Ceti has undergone a sudden decrease somewhere after 1976. The average period between 1976 and 1978 has been found to be 0d.1611335
  • 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 ...
  • On the photoconductivity of amethyst quartz 
    Bappu, M. K. V (Calcutta University Press, 1953-12)
    This paper describes an investigation of the photoconducting nature of amethyst quartz. Measurements of photocurreut were made for varying voltages, intensities, radiations and temperatures. A spectral sensitivity curve ...
  • On the Photometric Error Calibration for the Differential Light Curves of Point-like Active Galactic Nuclei 
    Goyal, Arti; Mhaskey, Mukul; Gopal-Krishna; Witta, P. J; Stalin, C. S; Sagar, R (Indian Academy of Sciences, 2013-09)
    It is important to quantify the underestimation of rms photometric errors returned by the commonly used APPHOT algorithm in the IRAF software, in the context of differential photometry of point-like AGN, because of the ...
  • On the photometric period of HD 81410 
    Raveendran, A. V; Mekkaden, M. V; Mohin, S (Konkoly Observatory, 1981-06)
  • on the physical characteristics of Wolf-Rayet Stars 
    Bappu, M. K. V (University of Bihar, 1959-11)
    The Wolf-Rayet stars form a group of objects that have numerous peculiar features in their spectra. They are so named after their discoverers Wolf and Rayet of the Paris Observatory who first picked out three examples ...
  • On the points of bifurcation along the sequence of rotating axisymmetric masses with magnetic fields 
    Kochhar, R. K (Indian Academy of Sciences, 1975-11)
    It is shown that the points of bifurcation belonging to the third harmonics along the sequence of Maclaurin spheroids viewed from an inertial frame are distinct from the corresponding points along the Maclaurin sequence ...
  • On the Polar Coronal Rays of the Sun 
    Bhatnagar, A; Raheem, K. C. A (Kodaikanal Observatory, 1970-10)
    A study of the polar coronal rays made on two eclipse photographs is presented. From the frequency distribution of polar rays, it is shown that the maximum distribution of polar rays occurs in an annular zone arround ...
  • On the possibility of nitrous oxide (N2O) as a cometary parent molecule in Comet 1P/Halley 
    Saxena, P. P (Astronomical Society of India, 2004-09)
    Nitrous oxide as a possible parent molecule in Comet 1P/Halley is discussed in light of in situ measurements and theoretical considerations. Hitherto undiscussed in cometary context, N2O could be a trace parent molecule ...

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