Browsing by Title

Sort by: Order: Results:

  • Optical follow-up of GRB afterglows from UPSO, Naini Tal 
    Pandey, S. B; Sagar, R; Mohan, V; Pandey, A. K; Bhattacharya, D; Castro-Tirado, A. J (Astronomical Society of India, 2001)
    Successful optical photometric observations of five GRB afterglows namely GRB 990123, GRB 991208, GRB 991216, GRB 000301c and GRB 000926 have been carried out from State Observatory Naini Tal till 2000. The results and ...
  • Optical frequency standard with Sr+: a theoretical many-body approach 
    Sur, S; Latha, K. V. P; Chaudhuri, R. K; Das, B. P; Mukherjee, D (World Scientific Publishing Co, 2007)
    Demands from several areas of science and technology have lead to a worldwide search for accurate optical clocks with an uncertainty of 1 part in $10^{18}$, which is $10^{3}$ times more accurate than the present day cesium ...
  • Optical glass: its manufacture in India — a historical perspective 
    Saxena, A. K; Vagiswari, A; Manjula, M (Indian National Science Academy, 1991)
    A historical perspective of optical glass industry in India has been presented in this paper. In this introduction a clear definition and understanding of optical glass is given. This is followed by world perspective. The ...
  • Optical identification and BVRI photometry of a few 'unidentified' IRAS sources of a late type stellar nature 
    Iyengar, K. V. K (Astronomical Society of India, 1993)
    A search for the optical counterparts of 21 'unidentified' IRAS sources was carried out using the Palomar Observatory Sky Survey (POSS), European Space Observatory (ESO) and Space Engineering Research Center (SERC) Sky ...
  • Optical identification of equatorial infrared catalogue number 1 sources previously identified with only AFGL sources 
    Iyengar, K. V. K; Tandon, S. N; Verma, R. P (Astronomical Society of India, 1983-09)
    We have identified, using Palomar Observatory Sky Survey (POSS) prints, the optical counterparts of six of the seven sources from the Equatorial Infrared Catalogue Number 1 (EIC-1) previously identified by Sweeney et al. ...
  • Optical identification of XMM sources in the Canada-France-Hawaii telescope legacy survey 
    Stalin, C. S; Petitjean, P; Srianand, R; Fox, A. J; Coppolani, F; Schwope, A (Blackwell Publishing, 2010-01)
    We present optical spectroscopic identifications of X-ray sources in similar to 3 deg2 of the XMM-Large Scale Structure survey (XMM-LSS), also covered by the Canada-France-Hawaii Telescope Legacy Survey (CFHTLS), obtained ...
  • Optical interferometer measurements of thermospheric temperature at Kavalur (12.5 deg N, 78.5 deg E), India 
    Sastri, J. H; Rao, H. N. R (Elsevier, 1994-02)
    First results on the behavior of thermospheric temperature over Kavalur (12.5 deg N, 78.5 deg E geographic; 2.8 deg N geomagnetic latitude) located close to the geomagnetic equator in the Indian zone are presented. The ...
  • Optical interferometric observations of a transient event of 1986 March 13 in the coma of Comet Halley 
    Prasad, D. C; Chandrasekhar, T; Desai, J. N; Ashok, N. M; Krishan, V (Indian Academy of Sciences, 1989-03)
    During the recent apparition of Comet Halley in 1985-86, a transient ionic event in the form of a blob of H2O(+) emission was recorded in the coma at about 0 h UT on March 13, 1986. Observations were carried out using a ...
  • Optical limiting in bacteriorhodopsin using a four-state model for two-beam illumination 
    Jagadish, C. S; Prashant, S. T; Prasad, B. R; Venkataramaniah, K; Sivasankara Sai, S (Department of Applied Optics and photonics, University of Calcutta, 2009)
    In this paper we have discussed a four state model in bacteriorhodopsin (bR) for two beam illumination. The paper presents simulation studies showing the change in the population levels of the various states in the bR ...
  • Optical linear polarization in ultra cool dwarfs: A tool to probe dust in the ultra cool dwarf atmospheres 
    Tata, R; Martin, E. L; Sengupta, S; Phan-Bao, N; Zapatero Osorio, M. R; Bouy, H (European Space Agency, 2009-12)
    Aims.Recent studies have detected linear polarization in L dwarfs in the optical I band. Theoretical models have been developed to explain this polarization. These models predict higher polarization at shorter wavelengths. ...
  • Optical metrology on primary mirror of visible emission line coronagraph on board Aditya-L1 mission 
    Venkata Suresh, Narra; Singh, Darshika; Venkatasubramanian, N; Budhiraju, Vishweshwar Rao; Hegde, Bhavana; Bhat, Nishchith; Utkarsha, D; Somasundaram, P. K; Ramaswamy, Venkateswaran; Kamath, P. U; Sriram, Kuppuswamy Venkatesan; Prasad, B. R (SPIE-Society of Photo-Optical Instrumentation Engineers, 2022-10)
    The visible emission line coronagraph (VELC) on board the Aditya-L1 mission is an internally occulted reflective coronagraph. It is capable of simultaneous observations of the solar corona in imaging, spectroscopic, and ...
  • Optical microvariability in radio quiet quasars 
    Wiita, P. J; Gopal-Krishna; Sagar, R (Kluwer Academic Publishers, 1994)
    We have observed 11 radio quiet QSOs (RQQSOs) to see if they exhibit intranight variability in the optical. The detection of such microvariability would support models in which flutuations on accretion disks are dominant, ...
  • Optical Microvariability of Blazars 
    Ghosh, K. K; Kim, C; Ramsey, B. D; Soundararajaperumal, S (Korean Astronomical Society, 2001-04)
    We present the results of optical differential photometry of five blazars [PKS 0219+428(3C66A), PKS 0235+164(AO 0235+16), H0414+019, PKS 0851+202(OJ 287), and QSO 1807+698(3C371)] that were observed on 7 nights between ...
  • Optical Nuclei of Radio-loud AGN and the Fanaroof-Riley Divide 
    Kharb, P; Shastri, P (EDP Sciences, 2004-10)
    We investigate the nature of the point-like optical nuclei that have been found in the centres of the host galaxies of a majority of radio galaxies by the Hubble Space Telescope. We examine the evidence that these optical ...
  • Optical observational programs at the Indian Institute of Astrophysics 
    Singh, J; Ravindra, B (Astronomical Society of India, 2011)
    The Indian Institute of Astrophysics has been making optical observations of the sun for more than a century by taking images of the sun in continuum to study the photosphere, Ca-K line and H-alpha line in order to study ...
  • Optical observations and dust modelling of comet 156P/Russell-LINEAR 
    Aravind, K; Halder, Prithish; Ganesh, Shashikiran; Sahu, D. K; Serra-Ricart, Miquel; Chambo, Jose J; Angchuk, D; Sivarani, T (Elsevier B.V., 2022-09-01)
    Comet 156P/Russell-LINEAR is a short period Jupiter family comet with an orbital period of 6.44 years. The results from spectroscopic, photometric, polarimetric observations and dust modelling studies are presented here. ...
  • Optical observations and multiband modelling of the afterglow of GRB041006 : Evidence of a hard electron energy spectrum 
    Misra, K; Resmi, L; Pandey, S. B; Bhattacharya, D; Sagar, R (Astronomical Society of India, 2005-12)
    We present the CCD Cousins R band photometric observations of the afterglow of GRB 041006. The multiband afterglow evolution is modelled using an underlying `hard' electron energy spectrum with a p1 ~ 1.3. The burst appears ...
  • Optical Observations of a Lunar Meteor Event during Leonid Meteor Showers in 2001 
    Chandrasekhar, T; Kikani, P. K; Mathur, S. N (Astronomical Society of India, 2003)
    We report a probable transient lunar meteor event observed during careful video recording of the unlit portion of the moon during the Leonid shower activity on 18th November 2001. A video CCD was attached to the 1.2m ...
  • Optical Observations of Geostationary Satellites 
    Dixit, P. S; Rao, P. K (Astronomical Society of India, 1978-12)
    A survey of celestial equator that is observable from Kavalur was made using satellite tracking camera AFU-75, to locate the positions of geostationary satellites that are accessible within the capabilities of camera from ...
  • Optical observations of GRB 060124 afterglow: a case for an injection break 
    Misra, K; Bhattacharya, D; Sahu, D. K; Sagar, R; Anupama, G. C; Castro-Tirado, A. J; Guziy, S. S; Bhatt, B. C (EDP Sciences, 2007-03)
    Aims.We present broad band optical afterglow observations of a long duration GRB 060124 using the 1.04-m Sampurnanand Telescope at ARIES, Nainital and the 2.01-m HCT at IAO, Hanle, including the earliest ground-based ...

Search DSpace

Browse

My Account