Browsing by Title

Sort by: Order: Results:

  • Plasma mechanisms for variability in active galactic nuclei 
    Krishan, V; Wiita, P J (1994-03)
    We consider several physical processes, dominated by plasma effects, that might play roles in producing variability in Active Galactic Nuclei (AGN). One class of processes involves oscillations in the plasma itself. If ...
  • Plasma wave aided two photon decay of an electromagnetic wave in a plasma 
    Magesh Kumar, K. K; Singh, R; Krishan, V (American Institute of Physics Publishing, 2014-11)
    The presence of a Langmuir wave in an unmagnetized plasma is shown to allow parametric decay of an electromagnetic wave into two electromagnetic waves, which is otherwise not allowed due to wave number mismatch. The decay ...
  • Plasmas: the first state of matter 
    Krishan, V (Cambridge University Press, 2014)
    Most astronomers believe that the universe began about 15 billion years ago when an explosion led to its expansion and cooling. The present state of the universe compels us to believe that the universe was extremely hot ...
  • Plume-like structures of extinction clouds at 19 Saturn radii 
    Vasundhara, R; Bhattacharyya, J. C; Rozario, M (Astronomical Society of India, 1986-12)
    Observations of the occultation of the star SAO 158763 by Saturn's magnetospheric region around 19 Saturn radii on May 12, 1984 are compared with the observations by Mahra et al. (1985) of the same event. Certain disparities ...
  • Pluto's Atmosphere in Plateau Phase Since 2015 from a Stellar Occultation at Devasthal 
    Sicardy, Bruno; Nagarhalli M, Ashok; Tej, Anandmayee; Pawar, Ganesh; Deshmukh, Shishir; Deshpande, Ameya; Sharma, Saurabh; Desmars, Josselin; Assafin, Marcelo; Ortiz, Jose Luis; Benedetti-Rossi, Gustavo; Braga-Ribas, Felipe; Vieira-Martins, Roberto; Santos-Sanz, Pablo; Chand, Krishan; Bhatt, B. C (IOP Publishing, 2021-12-20)
    A stellar occultation by Pluto was observed on 2020 June 6 with the 1.3 m and 3.6 m telescopes located at Devasthal, Nainital, India, using imaging systems in the I and H bands, respectively. From this event, we derive ...
  • PM asks Indian Scientists' to return home 
    Deccan Herald (Deccan Herald, 1986-01-07)
  • Pointing of HAGAR telescope mirrors 
    Gothe, K. S; Prabhu, T. P; Vishwanath, P. R; Acharya, B. S; Srinivasan, R; Chitnis, V. R; Kamath, P. U; Srinivasulu, G; Saleem, F; Kemkar, P. M. M; Mahesh, P. K; Gabriel, F; Manoharan, J; Dorji, N; Dorjai, T; Angchuk, D; D'souza, A. I; Duhan, S. K; Nagesh, B. K; Rao, S. K; Sharma, S. K; Singh, B. B; Sudersanan, P. V; Thsering, M. T; Upadhya, S. S; Anupama, G. C; Britto, R. J; Cowsik, R; Saha, L; Shukla, A (Springer, 2013-04)
    An array of seven atmospheric Cherenkov telescopes was commissioned at a high altitude site in Hanle in the Ladakh region of the Himalayas. The array called HAGAR has been designed to observe celestial γ-rays of energy ...
  • Pointing system for the balloon-borne astronomical payloads 
    Nirmal, K; Sreejith, A. G; Mathew, J; Mayuresh, Sarpotdar; Ambily, S||Prakash, A; Safonova, M; Murthy, J (SPIE-The International Society for Optical Engineering, 2016-12)
    We describe the development and implementation of a light-weight, fully autonomous 2-axis pointing and stabilization system designed for balloon-borne astronomical payloads. The system is developed using offthe-shelf ...
  • Pointing-accuracy for the 1.2m Gurushikhar telescope - measurement and improvement 
    Bobra, A. D; Subhedar, D. V; Banerjee, D. P. K (Astronomical Society of India, 1998)
  • Polar Network Index as a Magnetic Proxy for the Solar Cycle Studies 
    Priyal, M; Banerjee, D; Karak, B. B; Munoz-Jaramillo, A; Ravindra, B; Choudhuri, A. R; Singh, J (IOP Publishing, 2014-09-20)
    The Sun has a polar magnetic field which oscillates with the 11 yr sunspot cycle. This polar magnetic field is an important component of the dynamo process which operates in the solar convection zone and produces the sunspot ...
  • Polarimetric analysis of the Thirty Meter Telescope (TMT) for modeling instrumental polarization characteristics 
    Atwood, J; Skidmore, W; Anupama, G. C; Ramya, M. Anche; Krishna Reddy; Sen, Asoke (SPIE--The International Society for Optical Engineering, 2014-08)
    The Thirty Meter Telescope (TMT) will be called upon to support a polarimetric observing capability. Many different observing programs covering a range of different science areas are being considered for the TMT and a model ...
  • Polarimetric and photometric investigation of the dark globule LDN 1225: distance, extinction law, and magnetic fields 
    Eswaraiah, C; Lai, Shih-Ping; Ma, Yuehui; Anil K. Pandey; Jose, J; Chen, Zhiwei; Samal, M. R; Wang, Jia-Wei; Sharma, S; Ojha, D. K (IOP Publishing, 2019-04-10)
    We present results based on the optical R-band observations of the polarization of 280 stars distributed toward the dark globule LDN 1225. Parallaxes from Gaia data release 2 along with the polarization data of ~200 stars ...
  • Polarimetric and spectroscopic study of radio quiet weak emission line quasars 
    Kumar, P; Chand, H; Srianand, R; Stalin, C. S; Petitjean, P; Gopal-Krishna (Oxford University Press on behalf of the Royal Astronomical Society, 2018-10)
    A small subset of optically selected radio-quiet quasars showing weak or no emission lines may turn out to be the elusive radio-quiet BL Lac objects, or simply be radio-quiet QSOs with a still-forming/shielded broad line ...
  • Polarimetric and spectroscopic study of the weak-emission T Tauri star V 410 Tauri 
    Mekkaden, M. V (European Southern Observatory, 1999-04)
    Results of the polarimetric and spectroscopic observations of the weak emission T Tauri star V 410 Tau are presented. The linear polarization and position angle are found to show variability with a period corresponding to ...
  • Polarimetric detection of exoplanets transiting T and L brown dwarfs 
    Sengupta, S (IOP Publishing, 2016-10)
    While scattering of light by atoms and molecules yields large amounts of polarization at the B-band of both T and L dwarfs, scattering by dust grains in the cloudy atmosphere of L dwarfs gives rise to significant polarization ...
  • Polarimetric observations of comet P/Halley on 19 March 1986 
    Sen, A. K; Joshi, U. C; Deshpande, M. R; Babu, G. S. D; Kulshrestha, A. K (European Southern Observatory, 1988-10)
    Optical linear polarization data are presented for the coma and tail region of comet P/Halley observed on 19 March 1986. Polarization in the continuum has been found to increase with wavelength while the position angle ...
  • Polarimetric observations of hydrogen deficient stars 
    Raveendran, A. V; Kameswara Rao, N; Deshpande, M. R; Joshi, U. C; Kulshrestha, A. K (Reidel Publishing Company, 1986)
    Polarimetric observations of HD 30353, SU Tau, XX Cam, R CrB, UV Cas, BD +13°3224, BD +10°2179 and HD 124448 are presented. The linear polarization of HD 30353 is found to vary appreciably at Hα over a time scale as short ...
  • Polarimetric observations of the RV Tauri star AR Puppis 
    Raveendran, A. V; Kameswara Rao, N (European Southern Observatory, 1988-03)
    UBVRI polarimetry of AR Pup is presented. Large variations are seen both in the amount and direction of polarization. On one occasion, the polarization in U was found to be as high as 14.6 percent. Polarization level ...
  • Polarimetric studies of carbon stars at high galactic latitude 
    Goswami, A; Drisya, K (EDP Sciences, 2013-01)
    Context. Very little is known about the polarimetric properties of CH stars and carbon-enhanced metal-poor (CEMP) stars, although many of these objects have been studied in detail both photometrically and spectroscopically. Aims. ...
  • Polarimetric study of comets from Mt. Abu observatory 
    Joshi, J. C (Astronomical Society of India, 2005-06)
    The sunlight is scattered by the dust grains present in the coma and tail of comets which makes it visible. The scattered sunlight is characteristically polarized with degree of polarization generally depending upon the ...

Search DSpace

Browse

My Account