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Browsing by Author "Sagar, R"

Browsing by Author "Sagar, R"

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  • UBV photoelectric photometry of the open cluster NGC 2539 
    Joshi, U. C; Sagar, R (Astronomical Society of Indian, 1986-06)
    UBV photometric observations of 135 stars near NGC 2539, obtained using the 104-cm Sampurnanand reflector at Uttar Pradesh State Observatory during 1975-1978, are reported. The data are presented in tables and graphs and ...
  • UBVRI CCD photometry of the OB associations Bochum 1 and Bochum 6 
    Yadav, R. K. S; Sagar, R (Astronomical Society of India, 2003)
    We report the first deep $UBVRI$ CCD photometry of 2460 stars in the field of two poorly studied OB associations Bochum 1 and Bochum 6. We selected 15 and 14 probable members in Bochum 1 and Bochum 6 respectively using ...
  • UBVRI CCD photometry of the two southern galactic star clusters Berkeley 79 and Trumpler 11 
    Sagar, R; Cannon, R. D (Astronomical Society of India, 1994)
  • Unusual optical quiescence of the classical BL Lac object PKS 0735+178 on intranight time scale 
    Goyal, A; Gopal-Krishna; Anupama, G. C; Sahu, D. K; Sagar, R; Britzen, S; Karouzos, M; Aller, M. F; Aller, H. D (Wiley Blackwell, 2009-07)
    We present the result of our extensive intranight optical monitoring of the well known low-energy peaked BL Lac (LBL) object PKS 0735+178. This long-term follow-up consists of $R$-band monitoring for a minimum duration of ...
  • UOCS – III. UVIT catalogue of open clusters with machine learning-based membership using Gaia EDR3 astrometry 
    Jadhav, Vikrant K; Pennock, C. M; Subramaniam, A; Sagar, R; Prasanta Kumar Nayak (Oxford University Press on behalf of the Royal Astronomical Society, 2021-05)
    We present a study of six open clusters (Berkeley 67, King 2, NGC 2420, NGC 2477, NGC 2682, and NGC 6940), using the Ultra Violet Imaging Telescope (UVIT) aboard ASTROSAT and Gaia EDR3. We used combinations of astrometric, ...
  • UOCS. IV. discovery of diverse hot companions to blue stragglers in the old open cluster King 2 
    Jadhav, Vikrant V; Pandey, Sindhu; Subramaniam, A; Sagar, R (Indian Academy of Sciences, 2021-10)
    King 2, one of the oldest clusters in the Milky Way, with an age of ∼6 Gyr and distance of ∼5700 pc, has been observed with UVIT payload on the AstroSat. With membership information derived from Gaia EDR3, the cluster is ...
  • UOCS. XIII. Study of the Far-ultraviolet Bright Stars in the Open Cluster NGC 2420 Using AstroSat 
    Yadav, R. K. S; Dattatrey, Arvind K; Rangwal, Geeta; Subramaniam, A; Bisht, D; Sagar, R (American Astronomical Society, 2024-02-01)
    We present the study of four far-ultraviolet (FUV) bright stars in the field of the open cluster NGC 2420 using the Ultra Violet Imaging Telescope mounted on AstroSat. The three stars 525, 527, and 560 are members, while ...
  • UPSO three channel fast photometer 
    Gupta, S. K; Sagar, R; Joshi, S; Ashoka, B. N; Babu, V. C; Seetha, S; Girish, V (Astronomical Society of India, 2001)
    The design and performance of a modular portable three channel fast photometer is described. It can be disassembled as single individual channels such that the system can also be used as a single channel photometer. The ...
  • V, I CCD photometry of metal-rich bulge globular clusters: NGC 6553 
    Sagar, R; Subramaniam, A; Richtler, T; Grebel, E. K (The European Southern Observatory, 1999-03)
    We have carried out VI CCD photometry of about 40 000 stars down to V ~ 23 mag in an area of about 6' x 10' centered on the metal-rich Galactic bulge globular cluster NGC 6553 and an adjacent field region. Our photometry ...
  • VI CCD photometry of metal-rich globular clusters: NGC 6528 
    Richtler, T; Grebel, E. K; Subramaniam, A; Sagar, R (European Southern Observatory, 1998-01)
    We present CCD photometry in V and I for the metal-rich globular cluster NGC 6528. A comparison with previous photometry reveals discrepancies of the order 0.1 to 0.2 mag in V, emphasizing the need for independent photometry. ...
  • Wide Field CCD Photometry of the Young Open Cluster NGC 663 
    Pandey, A. K; Upadhyay, K; Ogura, K; Sagar, R (Astronomical Society of India, 2003)
    A deep and wide field CCD photometry of the young open cluster NGC 663 has been carried out. We report preliminary results of our investigations, specifically the determination of the cluster mass function which is found ...
  • Young LMC star clusters as a test for stellar evolutionary models. 
    Subramaniam, A; Sagar, R (The European Southern Observatory, 1995-05)
    We compare the observed colour-magnitude diagrams (CMD) and the main sequence luminosity functions (LFs) of four Large Magellanic Cloud (LMC) star clusters namely, NGC 1711, NGC 2004, NGC 2164 and NGC 2214 with the synthetic ...
  • The Young Open Star Clusters: Stability and Structure 
    Pandey, A. K; Mahra, H. S; Sagar, R (American Astronomical Society, 1990-02)
    It is found to the differential extinction ΔE (B-V) in open clusters which may be due to the presence of gas and dust, decreases systematically with age of the cluster. Consequently we can infer that the average gas removal ...
  • Young star clusters of our galaxy and the large magellanic cloud as test for stellar evolutionary models 
    Sagar, R; Subramaniam, A (Universidad Nacional Autonoma de Mexico, 1999)
    A comparison of the colour-magnitude diagrams (CMDs) and the main sequence luminosity function (LF) of five young Galactic star clusters and four young Large Magellanic Cloud star clusters derived from precise CCD observations ...

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