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Browsing by Author "Sagar, R"

Browsing by Author "Sagar, R"

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  • Search for Microlensing Events Towards M31 Galaxy 
    Joshi, Y. C; Pandey, A. K; Narasimha, D; Sagar, R (Astronomical Society of India, 2001)
    M31, the prominent galaxy of the Local Group, is located at a distance of about 700 kpc. Due to its convenient orientation, it is an alluring target for gravitational microlensing to search for massive astrophysical compact ...
  • Seeing and microthermal measurements near Devasthal top 
    Stalin, C. S; Sagar, R; Pant, P; Mohan, V; Kumar, B; Joshi, Y. C; Yadav, R. K. S; Joshi, S; Chandra, R; Durgapal, A. K; Uddin, W (Astronomical Society of India, 2001)
    Results of the seeing measurements carried out near Devasthal top on 43 nights during March to April 1999 are presented. Open air seeing measurements were carried out with a differential image motion monitor (DIMM) using ...
  • Site characterization for the UPSO-TIFR telescope 
    Sagar, R; Uddin, W; Pandey, A. K; Stalin, C. S; Mohan, V; Sanwal, B. B; Gupta, S. K; Yadav, R. K. S; Durgapal, A. K; Joshi, S; Kumar, B; Gupta, A. C; Joshi, Y; Srivastava, J. B; Chaubey, U. S; Singh, M; Pant, P; Gupta, K. G; Padalia, T. D (Astronomical Society of India, 2000)
    The Uttar Pradesh State Observatory, Naini Tal and Tata Institute of Fundamental Research, Mumbai plan to install jointly a 3 metre size optical telescope at Devasthal located east of Naini Tal about 50 km by road. The ...
  • Sky transparency over Naini Tal : A retrospective study 
    Kumar, B; Sagar, R; Rautela, B. S; Srivastava, J. B; Srivastava, R. K (Astronomical Society of India, 2000)
    We present an analysis of the atmospheric extinction coefficients measured during 1964 to 1999 in broad-band photometric passbands at U.P. State Observatory, Naini Tal. The extinction properties are also studied from the ...
  • SN 1993J in M 81: Optical photometry and spectrophotometry during the first two months 
    Prabhu, T. P; Mayya, Y. D; Singh, K. P; Kameswara Rao, N; Ghosh, K. K; Mekkaden, M. V; Pati, A. K; Raveendran, A. V; Reddy, B. E; Sagar, R; Subramaniam, A; Surendiranath, R (The European Southern Observatory, 1995-03)
    CCD photometric and spectrophotometric data on the type IIb supernova 1993J in M 81 (NGC 3031) obtained from Vainu Bappu Observatory, Kavalur, during the first two months since the outburst are reported. The evolution of ...
  • SN 2002ap, the Hypernova of Class Ic 
    Pandey, S. B; Sahu, D. K; Anupama, G. C; Bhattacharya, D; Sagar, R (Astronomical Society of India, 2003)
    The supernova SN 2002ap was discovered in the outer regions of the nearby spiral M74 on January 29.4 UT. Early photometric and spectroscopic observations indicate the supernova belongs to the class of Ic hypernova. Late ...
  • Spatial Distribution of Stellar Mass in the Large Magellanic Cloud Star Clusters 
    Subramaniam, A; Sagar, R; Bhatt, H. C (European Southern Observatory, 1993-06)
    The stellar mass distributions have been studied in halo regions (radius ranging from ~19 to 94 arcsec) of 5 young Large Magellanic Cloud star clusters. Effects of mass segregation have been observed in only NGC 1711. A ...
  • SS 433: results of a recent multiwavelength campaign 
    Chakrabarti, S. K; Anandarao, B. G; Pal, S; Mondal, S; Nandi, A; Bhattacharyya, A; Mandal, S; Sagar, R; Pandey, J. C; Pati, A. K; Saha, S. K (Royal Astronomical Society, 2005-09)
    We conducted a multiwavelength campaign in 2002 September-October, to observe SS 433. We used the Giant Meter Radio Telescope for radio observations, the Physical Research Laboratory Infrared Telescope at Mt Abu for infrared ...
  • Star clusters in the magellanic clouds II. age-dating, classification, and spatio-temporal distribution of the SMC clusters 
    Nayak, P. K; Subramaniam, A; Choudhury, S; Sagar, R (EDP Sciences, 2018-08)
    Aims. We aim to estimate the age and reddening parameters of already identified star clusters within the Small Magellanic Cloud (SMC) in a consistent way using available photometric data, classify them based on their mass ...
  • Star clusters in the magellanic clouds-1: parameterisation and classification of 1072 clusters in the LMC 
    Nayak, P. K; Subramaniam, A; Choudhury, S; Indu, G; Sagar, R (Oxford University Press on behalf of the Royal Astronomical Society, 2016-12-01)
    We have introduced a semi-automated quantitative method to estimate the age and reddening of 1072 star clusters in the Large Magellanic Cloud (LMC) using the Optical Gravitational Lensing Experiment III survey data. This ...
  • Star Formation in the Dwarf Seyfert Galaxy NGC 4395: Evidence for Both AGN and SN Feedback? 
    Nandi, Payel; Stalin, C. S; Saikia, D. J; Muneer, S; Mountrichas, George; Wylezalek, D; Sagar, R; Patig, M. K (American Astronomical Society, 2023-06-20)
    We present a detailed multiwavelength study of star formation in the dwarf galaxy NGC 4395, which hosts an active galactic nucleus (AGN). From our observations with the Ultra-Violet Imaging Telescope, we have compiled a ...
  • Star formation in young cluster NGC 1893 
    Sharma, S; Pandey, A. K; Ojha, D. K; Chen, W. P; Ghosh, S. K; Bhatt, B. C; Maheswar, G; Sagar, R (International Astronomical Union, 2008-05)
    We have carried out a multi-wavelength study of the star forming region NGC 1893 to make a comprehensive exploration of the effects of massive stars on low mass star formation. Using deep optical U BV RI broad band, Hα ...
  • Star formation in young star cluster NGC1893 
    Sharma, S; Pandey, A. K; Ojha, D. K; Chen, W. P; Ghosh, S. K; Bhatt, B. C; Maheswar, G; Sagar, R (Blackwell Publishing, 2007-09)
    We present a comprehensive multiwavelength study of the star-forming region NGC 1893 to explore the effects of massive stars on low-mass star formation. Using near-infrared colours, slitless spectroscopy and narrow-band ...
  • Star-clusters in the magellanic clouds and their mass functions 
    Sagar, R (Indian Academy of Sciences, 1993-03-10)
  • Stellar contents of two young open clusters: NGC 663 and 654 
    Pandey, A. K; Upadhyay, K; Ogura, K; Sagar, R; Mohan, V; Mito, H; Bhatt, H. C; Bhatt, B. C (Royal Astronomical Society, 2005-04)
    UBVRI CCD photometry in a wide field around two young open clusters, NGC 663 and 654, has been carried out. Hα and polarimetric observations for the cluster NGC 654 have also been obtained. We use the photometric data to ...
  • Steps toward determination of the size and structure of the broad-line region in active galactic nuclei. 6: Variability of NGC 3783 from ground-based data 
    Stirpe, G. M; Winge, C; Altieri, B; Alloin, D; Aguero, E. L; Anupama, G. C; Ashley, R; Bertram, R; Calderon, J. H; Catchpole, R. M; Corradi, R. L. M; Covino, E; Dottori, H. A; Feast, M. W; Ghosh, K. K; Hutton, R. Gil; Glass, I. S; Grebel, E. K; Jorda, L; Koen, C; Laney, C. D; Maia, M; Marang, F; Mayya, Y. D; Morrell, N; Nakada, Y; Pastoriza, M. G; Pati, A. K; Pelat, D; Peterson, B. M; Prabhu, T. P; Roberts, G; Sagar, R; Salamanca, I; Sekiguchi, K; Storchi-Bergmann, T; Subramaniam, A; Van Winckel, H; Van Wyk, F; Villada, M; Wagner, R. M; Whitelock, P. A; Winkler, H; Clavel, J; Dietrich, M; Kollatschny, W; O'Brien, P. T; Perola, G. C; Recondo-Gonzalez, M. C; Rodriguez-Pascual, P; Santos-Lleo, M (The American Astronomical Society, 1994-04)
    The Seyfert 1 galaxy NGC 3783 was intensely monitored in several bands between 1991 December and 1992 August. This paper presents the results from the ground-based observations in the optical and near-IR bands, which ...
  • Study of interstellar extinction in some young open clusters 
    Sagar, R (Royal Astronomical Society, 1987-09)
    Interstellar extinction has been studied in 15 open clusters, based on reliable cluster members and precise observational data. Out of these, 10 show nonuniform extinction across the cluster region. Most of these show ...
  • A study of spatial structure of galactic open star clusters 
    Nilakshi; Sagar, R; Pandey, A. K; Mohan, V (E D P Sciences, 2002-02)
    In order to study the relation between the core and corona in galactic star clusters, the spatial structure of 38 rich open star clusters has been studied using radial density profiles derived from the photometric data of ...
  • Study of the Galactic Cluster NGC 581 
    Sagar, R; Joshi, U. C (Astronomical Society of India, 1978-03)
    Photoelectric magnitudes and colours in the UBV system have been determined for 73 stars in NGC 581. The value of the interstellar reddening is 0m.38. The distance modules to the cluster is estimated at 12m.16 plus or ...
  • A study of the old galactic star cluster Berkeley 32 
    Richtler, T; Sagar, R (Astronomical Society of India, 2001)
    We present new CCD photometry of the distant old open star cluster Berkeley 32 in Johnson V and Cousins I passbands. A total of ~ 3200 stars have been observed in a field of about 13? x 13?. The colour-magnitude diagram ...

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