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  • Bhattacharyya, J. C; Sundareswaran. A (Indian Institute of Astrophysics, Bangalore, 1977)
    An electronic system for recording fast light curves is described. The system employs a two track magnetic tape recorder for intermediate storage of photometer and time signals and reproduces these on cathode ray oscilloscope ...
  • Mathur, S; Garcia, R. A; Regulo, C; Ballot, J; Salabert, D; Chaplin, W. J (American Institute of Physics, 2009)
    The Kepler mission will provide a huge amount of asteroseismic data during the next few years, among which hundreds of solar‐like stars will be targeted. The amount of stars and their observation length represent a step ...
  • Louis, R. E; Ravindra, B; Georgoulis, M. K; Kuker, M (Springer, 2015-04)
    We employ different shapes of apodizing windows in the local correlation tracking (LCT) routine to retrieve horizontal velocities using numerical simulations of convection. LCT was applied on a time sequence of temperature ...
  • Louis, R. E; Ravindra, B; Mathew, S. K; Bellot Rubio, L. R; Bayanna, A. R; Venkatakrishnan, P (IOP Publishing, 2012-08-10)
    We employ high-resolution filtergrams and polarimetric measurements from Hinode to follow the evolution of a sunspot for eight days starting on 2007 June 28. The imaging data were corrected for intensity gradients, projection ...
  • Herrero, A; Parthasarathy, M; Simon-Diaz, S; Hubrig, S; Sarkar, G; Muneer, S (Oxford University Press on behalf of the Royal Astronomical Society, 2020-05)
    From an analysis of absorption lines in the high-resolution spectra, we have derived the radial velocities, stellar parameters (Teff, log g, wind-strength parameter log Q, and projected rotational velocity), and abundances ...
  • Pandya, T. P; Saxena, A. K (Indian Institute of Astrophysics, 1978)
    Following Jones Calculus, a comprehensive theory of the Babinet Compensator has been presented. The performance of the system governed by the compensator-Polaroid unit, has been evaluated in terms of fringe visibility. ...
  • Sreedevi, Anu; Jha, Bibhuti K; Karak, Bidya Binay; Banerjee, D (American Astronomical Society, 2024-05-01)
    One of the intriguing mechanisms of the Sun is the formation of bipolar magnetic regions (BMRs) in the solar convection zone (CZ), which are observed as regions of concentrated magnetic fields of opposite polarity on ...
  • Singh, J; Jain, S. K (Indian Academy of Sciences, 1989-12)
    Observations of solar Ca(+) K daily plage area from 1951 to 1977 are analyzed to search for short-period (12-13 day) variations. The 27-day periodicity due to solar rotation modulation is found at all latitudes. Using an ...
  • Raju, K. P; Chandrasekhar, T; Ashok, N. M (IOP Publishing, 2011-08-01)
    Coronal green line (Fe XIV 5303 Å) profiles were obtained from Fabry-Perot interferometric observations of the solar corona during the total solar eclipse of 2001 June 21 from Lusaka, Zambia. The instrumental width is about ...
  • Nirupama Subrahmanyam (Government Observatory, Madras, 1962-10)
  • Vijayalakshmi, P; Shanmugaraju, A; Bendict Lawrance, M; Moon, Y.-J; Na, Hyeonock; Ebenezer, E (Springer, 2023-02)
    Halo coronal mass ejections (CMEs) from the Sun are the subset of CMEs, which are more energetic than the normal CMEs. Only the more energetic CMEs are observable in whitelight coronagraphs when they are traveling along ...
  • Chatzistergos, Theodosios; Ermolli, Ilaria; Krivova, Natalie A; Solanki, Sami K; Banerjee, D; Barata, Teresa; Belik, Marcel; Gafeira, Ricardo; Garcia, Adriana; Hanaoka, Yoichiro; Manjunath, H; Klimes, Jan; Korokhin, Viktor V; Lourenço, Ana; Malherbe, Jean-Marie; Marchenko, Gennady P; Peixinho, Nuno; Sakurai, Takashi; Tlatov, Andrey G (EDP Sciences, 2020-07)
    Context. Studies of long-term solar activity and variability require knowledge of the past evolution of the solar surface magnetism. The archives of full-disc Ca II K observations that have been performed more or less ...
  • Khare, P (Astronomical Society of India, 1996)
    Recent evidence suggesting that at least some of the Lyman alpha forest absorbers are not primordial and are indeed associated with galaxies is disucussed. Proximity effect, which deals with the change in the distribution ...
  • Vasundhara, R; Selvakumar, G; Anbazhagan, P (Oxford University Press on behalf of the Royal Astronomical Society, 2017-06)
    Results of analysis of 23 events of the 2014–2015 mutual event series from the Vainu Bappu Observatory are presented. Our intensity distribution model for the eclipsed/occulted satellite is based on the criterion that it ...
  • Ramya, M. Anche; Sen, A; Anupama, G. C; Sankarasubramanian, K; Skidmore, W (SPIE-The International Society for Optical Engineering, 2018-01)
    An analytical model has been developed to estimate the polarization effects, such as instrumental polarization (IP), crosstalk (CT), and depolarization, due to the optics of the Thirty Meter Telescope. These are estimated ...
  • Sagar, R (Astronomical Society of Indian, 1987-12)
    An analysis of the proper motion data and membership probability has been carried out for nine open clusters. The effects of observational errors on the parameters characterzing the frequency distributions of cluster and ...
  • Joshi, A; Uddin, W (Astronomical Society of India, 1991)
    We report the CaII K observations of a major umbral solar flare of optical class 3B which occurred on 1989 March 13. Correlated optical, microwave, soft X-ray (SXR), sudden ionospheric disturbance observations and the ...
  • Chowdhury, Partha; Ravindra, B; Bertello, Luca; Pevtsov, Alexei A (IOP Publishing, 2022-01-20)
    The Kodaikanal Observatory has provided long-term synoptic observations of chromospheric activities in the Ca ii K line (393.34 nm) since 1907. This article investigates temporal and periodic variations of the hemispheric ...
  • Brajesh, Kumar; Raja Bayanna, A; Venkatakrishnan, P; Kuchandy Mathew, S (IOP Publishing, 2016-08)
    The solar active region NOAA 11719 produced a large two-ribbon flare on 2013 April 11. We have investigated sudden variations in the photospheric magnetic fields in this active region during the flare by employing magnetograms ...
  • Bappu, M. K. V; Raghavan, Nirupama (Royal Astronomical Society, 1969)

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