IIA Institutional Repository: Recent submissions

  • The Nebular Remnant and Quiescent Spectrum of Nova Gk-Persei 
    Anupama, G. C; Prabhu, T. P (Royal Astronomical Society, 1993-07-15)
    CCD images of the nebular shell of the old nova GK Per in [N II] and [O III] emission lines, and also the quiescent spectrum in the optical region, are presented. Proper motion measurements of the knots in [N II]over the ...
  • Polarisation in A-type stars with circumstellar shells 
    Bhatt, H. C (European Southern Observatory, 1996-12)
    We present the results of optical linear polarisation measurements of about 30 A-type stars that are known to be either Ae/A shell stars or have shown anomalous emission in the infrared. Compared with the general population ...
  • Azimuthal structures in the wind and chromosphere of the Herbig AE star AB Aurigae. Results from the MUSICOS 1992 campaign 
    Boehm, T; Catala, C; Donati, J. F; Welty, A; Baudrand, J; Butler, C. J; Carter, B; Collier-Cameron, A; Czarny, J; Foing, B; Ghosh, K; Hao, J; Houdebine, E; Huang, L; Jiang, S; Neff, J. E; Rees, D; Semel, M; Simon, T; Talavera, A; Zhai, D; Zhao, F (European Southern Observatory, 1996-12)
    The observations of the MUSICOS 1992 campaign concerned three scientific programs, among which was the study of azimuthal structures in the wind and chromosphere of the pre-main sequence Herbig Ae star AB Aur. The He I ...
  • UBVR Polarimetry of the Peculiar R-Coronae Star V854-CENTAURI 
    Kameswara Rao, N; Raveendran, A. V (European Southern Observatory, 1993-07)
    We present UBVR polarimetry V 854 Cen obtained on four nights during February 1991-March 1992. Two sets of measurements are close to two nearby light maxima and the other two during the declines when the star was around 4 ...
  • Optical Emission Bands in the Spectrum of the R-Coronae and V854-CENTAURI at Minimum 
    Kameswara Rao, N; Lambert, D. L (Royal Astronomical Society, 1993-08-01)
    Several unidentified broad emission features, previously seen only in the spectrum of the nebulosity in the Red Rectangle, have been observed in a spectrum of the R CrB star V854 Cen taken in a deep minimum. Similarities ...
  • Polarized resonance line transfer with collisional redistribution 
    Mohan Rao, D (European Southern Observatory, 1993-07)
    In this paper we study the effect of depolarizing collisions on resonance line polarization in the absence of magnetic fields. The role of γ, the coherence parameter is investigated in determining the percentage of ...
  • Observations of the Rosette Nebula using the Decameter Wave Radio Telescope at Gauribidanur 
    Deshpande, A. A; Shevgaonkar, R. K; Sastry, Ch. V (D. Reidel Publishing Co., 1984-07)
    A map of Rosette Nebula in continuum absorption is made at 34.5 MHz using the Decameter Wave Radio Telescoe at Gauribidanur, India, with a resolution of 26×40, is presented. These observations are combined with the 2700 ...
  • Electric dipole and quadrupole transition amplitudes for Ba+ using the relativistic coupled-cluster method 
    Gopakumar, G; Merlitz, H; Chaudhuri, R. K; Das, B. P; Mahapatra, U. S; Mukherjee, D (The American Physical Society, 2002-09)
    We present our calculations of the electric dipole and quadrupole matrix elements for transitions between low-lying bound states of Ba1 that are relevant for parity nonconservation studies using the relativistic coupled-cluster ...
  • Photometric Variability of Four Coronally Active Stars 
    Pandey, J. C; Singh, K. P; Sagar, R; Drake, S. A (Indian Academy of Sciences, 2002-03)
    We present photometric observations of four stars that are optical counterparts of soft X-ray/EUV sources, namely 1ES 0829+15.9, 1ES0920-13.6, 2RE J110159+223509 and 1ES 1737+61.2. We have discovered periodic variability ...
  • New pulsating variables discovered from the Naini Tal-Cape survey 
    Seetha, S; Ashoka, B. N; Joshi, S; Girish, V; Sagar, R; Chaubey, U. S; Gupta, S. K (Astronomical Society of India, 2002-09)
    The Naini Tal-Cape survey has been initiated to search for pulsations in chemically peculiar A and F type stars. Many of the magnetic A peculiar type stars exhibit rapid oscillations with periods ranging from 4-16 minutes. ...
  • Search for activity signatures in T Thuri stars 
    Mekkaden, M. V (Astronomical Society of India, 2002-09)
    T Tauri stars are young, low mass, pre-main sequence stars. They exhibit a large variety of properties characteristic of earlier as well as later evolutionary phases and represent an important phase in the stellar ...
  • Study of Sun's rotation and solar activity 
    Javaraiah, J (Astronomical Society of India, 2002-09)
    In my thesis I have presented many interesting properties of Sun's rotation and magnetic activity derived from extensive analysis of over 100 year photoheliographic data on sunspot activity and 26 year's data on ...
  • Fluctuations in Moon's period and its relationship with the perigees of the Moon and the Sun 
    Ballabh, G. M; Alladin, S. M (Astronomical Society of India, 2002-09)
    Just as the regression of the nodes of the lunar orbit is connected with the periodicity in the eclipse phenomenon, the advance of perigee is connected with the periodicity in the fluctuations of Moon's synodic period. ...
  • Effect of solar wind streams on interplanetary features and on geomagnetic field 
    Singh, G. N; Shrivastava, P. K (Astronomical Society of India, 2002-09)
    High speed solar· wind streams are separated into two categories : (i) Corotating (ii) Flare-generated streams. Resul ts based on this analysis indicate the occurrence of large geomagnetic and interplanetary disturbances during ...
  • Quasi - periodic pulsations at decameter wavelengths in the November 24, 2000 solar flare 
    Subramanian, K. R; Ebenezer, E (Astronomical Society of India, 2002-09)
    Spectral observations of the Sun in the frequency range of 54 to 78 MHz in the November 24, 2000 solar flare showed quasi - periodic pulsations with periods in the range of 11 - 19 seconds. YOHKOH images of this flare ...
  • Studies on the E2-transition in CoXVII 
    Ray, H (EDP Sciences, 2002-09)
    The spectrum of the solar corona, plasma spectra, astrophysical objects and fusion devices exhibit forbidden lines in alkali-like ions. Ions belonging to the iron group are particularly important in this respect. More ...
  • Fading of light maximum and linear polarization variation in the carbon Mira R Leporis 
    Raveendran, A. V (Royal Astronomical Society, 2002-11)
    Polarimetry of R Lep obtained over the years 1991-2002 is presented. During this period the star underwent an episode of fading of the brightness at light maximum, after an interval of about 35 yr. An analysis of the data ...
  • Imaging Fabry-Perot observations of green coronal line during the total solar eclipse of 21 June 2001 
    Chandrasekhar, T; Ashok, N. M; Anandarao, B. G (Astronomical Society of India, 2002-09)
    A Fabry-Perot interferometric experiment on the Green Coronal line was successfully performed during the total solar eclipse of 21 June 2001 from Lusaka, Zambia. Use of a cooled CCD camera permitted 17 separate exposures ...
  • Spectroscopic Studies of the Solar Corona III. Density Diagnostics Using the Infrared Lines of Fe XIII 
    Singh, J; Sakurai, Takashi; Ichimoto, K; Takeda, Aki (Astronomical Society of Japan, 2002)
    We have obtained spectrographic observations of several coronal regions in three emission lines (6374Å [Fe X ], 10747Å [Fe XIII ], and 10798Å [Fe XIII ]) simultaneously. The 25-cm coronagraph at Norikura Observatory and ...
  • Studies on E2 Transition in the Na-like Highly Stripped Ion Fe XVI 
    Ray, H (The American Astronomical Society, 2002-11)
    The spectrum of the solar corona and plasma spectra in astrophysical objects and fusion devices exhibit forbidden lines in alkali-like ions. Ions belonging to the iron group are particularly important in this respect. The ...

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