IIA Institutional Repository: Recent submissions

  • Post-Sunset behaviour of the equatorial anomaly in the Indian sector 
    Sastri, J. H (The Council of Scientific and Industrial Research, 1982-02)
    A detailed Investigation is made of the relationship, In the post-sunset period, between the depth of the equatorial anomaly and the evening rise of F-region at the trough on a day-to-day basis, using pubhshed data ...
  • Equatorial spread-F configurations and geomagnetic activity 
    Sastri, J. H; Sasidharan, K; Subrahmanyam, V; Srirama Rao, M (The Council of Scientific and Industrial Research, 1978-11)
    Using quarter-hourly ionogram data at Kodaikanal (geomag. lat: 0.6°N; dip: 3•S0N) for the period 19.57-63 a study is made of the effect of geomagnetic activity on the occurrence of range and frequency types of spread-F. ...
  • Forenoon bite-out in f0F2 at low latitudes 
    Sastri, J. H; Ramesh, K. B (The Council of Scientific and Industrial Research, 1982-04)
    Evidence is presented showing that the longitudinal extent of the forenoon bite-out in f0F2 at low geomagnetic latitudes can sometimes be very narrow and that marked differences in the extent of the development of the ...
  • Phase variabilty of Sq (H) and the ionospheric equatorial anomaly 
    Sastri, J. H (The Council of Scientific and Industrial Research, 1982-04)
    A study is made of the behaviour of the equatorial ionization anomaly m the Indian region on days with an abnormal S/subq (H) phase limited to the electrojet belt. The anomaly is found to disappear or reduce in strength quite ...
  • 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 ...
  • Daytime equatorial VHF radiowave scintillations and sporadic-E layer 
    Koparkar, P. V; Rastogi, R. G; Sastri, J. H (The Council of Scientific and Industrial Research, 1989-08)
    Daytime VHF radiowave scintillations at Trivandrum are compared with the E-region irregularities at Kodaikanal. It is shown that daytime scintillations at Trivandrum are basically of two categories. One type of scintillations ...
  • Evolution of research in different astronomies in India 
    Bhattacharyya, J. C (The Council of Scientific and Industrial Research, 1986-10)
    The evolution of astronomical studies is reviewed with special reference to important achievements on Indian soil since the introduction of telescopic observations in the early seventeenth century. Important activities ...
  • Further spectroscopic observations of SN 1987A 
    Anupama, G. C; Prabhu, T. P; Ghosh, K. K; Ashoka, B. N; Giridhar, S (Elsevier, 1988)
    Spectroscopic observations of SN 1987a obtained during 1987 August 30 – September 8 from Vainu Bappu Observatory, Kavalur, are presented; the spectrum is compared and contrasted with the spectra recorded at earlier epochs. ...
  • Abnormal quiet days and the effect of geomagnetic activity on the diurnal variation of equatorial geomagnetic field 
    Sastri, J. H (The Council of Scientific and Industrial Research, 1983-04)
    It is shown that a conspicuous noontime positive deviation 10 the asymmetric component or the H field at equatorial electrojet stations, associated with the solar wind on quiet days with A/subp~5, does not manifest if ...
  • Occurrence of abnormal Sq (H) phase in the equatorial electrojet region 
    Sastri, J. H (Pergamon Press Ltd., 1981-07)
    From an analysis of published geomagnetic data of stations in the Indian equatorial region, it is shown that on days with an abnormal Sq (H) phase limited to the electrojet belt, conditions characteristic of complete or ...
  • Ejection of massive black holes from galaxies 
    Kapoor, R. C (Indian Academy of Sciences, 1976-11)
    Gravitational recoil of a gigantic black hole of about 10 to the 8th to 10 to the 9th solar masses formed in the nonspherical collapse of the nuclear part of a typical galaxy can take place with an appreciable speed as a ...
  • The large Magellanic cloud R CrB Star - HV 12842 
    Morgan, D. H; Nandy, K; Kameswara Rao, N (D. Reidel Publishing Co, 1986)
    This paper describes the behaviour of HV 12842 during the period 1976 - 1985 as it appears on the 38 I plates of LMC(N) taken with the UK 1.2 m Schmidt Telescope.
  • On the growth and decay of blanketing sporadic-E layers 
    Sastri, J. H (The Council of Scientific and Industrial Research, 1980-02)
    Vertical incidence ionospheric soundings with a C-3 ionosonde were performed at Kodaikanal (dip 3.5 deg N) at one minute intervals during October 1974-January 1975 with a view to monitoring the small scale fluctuations in ...
  • Photographic observation of the Moon`s position 
    Bappu, M. K. V (NISCAIR, 1958)
  • A spectroscopic study of the Scorpio-Centaurus association 
    Rajamohan, R (Indian Academy of Sciences, 1976-09)
    Rotational velocities for 112 members of the Scorpio-Centaurus association brighter than 8.5 magnitudes are derived from spectra obtained with a dispersion of 47 A/mm. Hydrogen and helium line intensities are determined ...
  • The frequency drift and time splitting of decameter solar radio bursts 
    Sastry, Ch. V (Gordon and Breach, Science Publishers Ltd., 1972-05)
    The frequency drift and time splitting of solar radio bursts are observed with a multi-channel radiometer and a polarimeter at frequencies around 25 MHz. It is found that a majority of noise storm bursts have drift ...
  • Ionospheric storm of 4 - 6 December 1958 in the Indian equatorial region. 
    Sastri, J. H (The Council of Scientific and Industrial Research, 1980-06)
    The characteristics of the ionospheric storm of 4-6 Dec. 1958 in the Indian sector (60-85°B) are studied using published data from ten ionospheric stations distributed from high mid latitudes to dip equator. It is shown ...
  • Torsion, time and temperature (The T/sup3 theorem) 
    de Sabbata, V; Sivaram, C (Allahabad Mathematical Society, 1991-06)
  • The time splitting of decameter solar radio bursts 
    Sastry, Ch. V (Gordon and Breach, Science Publishers Ltd., 1971-03)
    Solar radio bursts were observed with a multi-channel receiver with frequency separations of 100 to 200 kHz: at a center frequency of 25 MHz. The time resolution was 15 msec. Some properties of double bursts are described.
  • Orbit of the spectroscopic binary B Persei 
    Rajamohan, R; Parthasarathy, M (Indian Academy of Sciences, 1975-04)
    Spectroscopic orbital elements are derived for the close binary system b Persei on the basis of forty spectrograms. The period is redetermined as 1.527360 days, and variations in the orbital elements are confirmed by ...

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