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Browsing by Author "Subramaniam, A"

Browsing by Author "Subramaniam, A"

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  • A road map for the generation of a near-infrared guide star catalog for thirty meter telescope observations 
    Subramanian, S; Subramaniam, A; Sivarani, T; Simard, Luc; Anupama, G. C; Gillies, Kim; Ramaprakash, A. N; Reddy, B. E (Indian Academy of Sciences, 2016-09)
    The near-infrared instruments in the upcoming Thirty Meter Telescope (TMT) will be assisted by a multi conjugate Adaptive Optics (AO) system. For the efficient operation of the AO system, during observations, a near-infrared ...
  • RR lyrae stars in the inner large magellanic cloud: halo-like location with a disk-like distribution 
    Subramaniam, A (EDP Sciences, 2006-04)
    Aims. The distribution of RR Lyrae stars (RRLS) in the inner Large Magellanic Cloud (LMC), and the structure of the halo of the LMC delineated by these stars are studied here. Methods.RRLS identified by the OGLE II survey ...
  • RR Lyrae stars in the inner LMC: Where did they form? 
    Subramaniam, A; Subramanian, S (EDP Sciences, 2009-08)
    RR Lyrae stars (RRLS) belong to population II and are generally used as a tracer of the host galaxy halo. The surface as well as vertical distribution of RRLS in the inner Large Magellanic Cloud (LMC) are studied to ...
  • SAO 75669: A late type giant behind the molecular cloud MBM 12 
    Bhatt, H. C; Sagar, R; Subramaniam, A; Gorti, U; Chandrasekhar, T; Ashok, N. M; Ragland, S (European Southern Observatory, 1994-09)
    Photometric and spectroscopic observations of the star SAO 75669 in the region of the high galactic latitude molecular cloud MBM 12 are presented. The optical, near-infrared and far-infrared IRAS photometric magnitudes ...
  • Scientific potential of the Indo-Belgian 3.6-m DOT in the field of Galactic Astronomy 
    Sagar, R; Kumar, B; Subramaniam, A (Societe Royale des Sciences de Liege, 2019-10)
    India and Belgium have jointly established two 4-meter class optical telescopes at Devasthal located in Nainital, India. After successful installation of the 3.6-m modern new technology Devasthal Optical Telescope (DOT) ...
  • Short-Term H α Line Variations in Classical Be Stars: 59 Cyg and OT Gem 
    Paul, K. T; Shruthi, S. B; Subramaniam, A (Indian Academy of Sciences, 2017-03)
    We present the optical spectroscopic study of two classical Be stars, 59 Cyg and OT Gem obtained over a period of few months in 2009. We detected a rare triple-peak H α emission phase in 59 Cyg and a rapid decrease in the ...
  • Simulation of old open clusters for UVIT on ASTROSAT 
    Sindhu, N; Subramaniam, A; Anu Radha, C (IOP Publishing, 2015-10)
    The Ultra Violet Imaging Telescope (UVIT) is one of the payloads on the first Indian multiwavelength satellite ASTROSAT, which is expected to be launched by the Indian Space Research Organisation (ISRO) in the year 2015. ...
  • Smallest Scale Clumpy Star Formation in Stephan's Quintet Revealed from UV and IR Imaging 
    Joseph, P; George, K; Subramanian, S; Mondal, C; Subramaniam, A (IOP Publishing, 2022-09)
    The spatial distribution and physical sizes of star-forming clumps at the smallest scales provide valuable information on hierarchical star formation (SF). In this context, we report the sites of ongoing SF at ∼120 pc along ...
  • 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 ...
  • 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 ...
  • Spatiotemporal map of star clusters in the Magellanic Clouds using Gaia: synchronized peaks and radial shrinkage of cluster formation 
    Dhanush, S. R; Subramaniam, A; Nayak, Prasanta K; Subramanian, S (Oxford University Press on behalf of Royal Astronomical Society, 2024-02)
    We present a detailed view of cluster formation (CF) to trace the evolution and interaction history of the Magellanic Clouds (MCs) in the last 3.5 Gyr. Using the Gaia DR3 data, we parametrized 1710 and 280 star clusters ...
  • Spectroscopic study of a few Herbig Ae/Be stars in young open clusters 
    Mathew, B; Subramaniam, A; Bhavya, B (Astronomical Society of India, 2010-03)
    In this article we give an overview of the developments in the field of spectral classification and its continued importance in the fields of stellar and galactic evolution. The extension of MK system to cool stars as well ...
  • Spectroscopic study of Be-shell stars : 4 Her and 88 Her 
    Bhat, S. S; Paul, K. T; Subramaniam, A; Mathew, B (IOP Publishing, 2016-06)
    We present an optical spectroscopic study based on 41 spectr a of 4 Her and 32 spectra of 88 Her, obtained over a period of 6 months. We estimate the rotationa l velocity of these stars from He I lines in the blue ...
  • Spectroscopic survey of emission line stars in open clusters 
    Subramaniam, A; Mathew, B (Springer, 2010)
    We summarize a study of emission-line stars in young open clusters. The study was done in two phases. The first phase was the survey, where the emission stars in young open clusters were identified using the slitless ...
  • Spectroscopy of Be stars in young open clusters 
    Mathew, B; Subramaniam, A (Astronomical Society of India, 2010)
    A spectroscopic study of 152 Classical Be stars in 42 young open clusters was performed using medium resolution spectra in 3700-9000 A range, to understand the Be phenomenon. The Balmer decrement is found to have a ...
  • 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 region of young open cluster - NGC 225 
    Subramaniam, A; Mathew, B; Sreeja S. K (Astronomical Society of India, 2006-12)
    NGC 225 is believed to be a 120 Myr old open cluster located at tilda 650 pc. Eight stars with H alphaemission are found to be located around the cluster, of which two are probable Herbig Be stars, indicating a very young ...
  • Stara -Disk Interactions in Multiband Photometric Monitoring of the Classical T Tauri Star GI Tau 
    Guo, Zhen; Herczeg, Gregory J; Jose, J; Fu, Jianning; Chiang, Po-Shih; Grankin, Konstantin; Michel, R; Yadav, Ram Kesh; Liu, Jinzhong; Chen, Wen-Ping; Li, Gang; Xue, Huifang; Niu, Hubiao; Subramaniam, A; Sharma, Saurabh; Prasert, Nikom; Flores-Fajardo, Nahiely; Castro, Angel; Altamirano, Liliana (IOP Publishing, 2018-01)
    The variability of young stellar objects is mostly driven by star – disk interactions. In long-term photometric monitoring of the accreting T Tauri star GI Tau, we detect extinction events with typical depths ...
  • Stellar populations in the magellanic clouds 
    Subramanian, S; Subramaniam, A (Astronomical Society of India, 2013)
    The structural parameters of the Large Magellanic Cloud and the Small Magellanic Cloud are derived from the study of di erent stellar populations, such as, Cepheids (age 100 Myr), Red Clump stars (age 2-9 Gyr) and RR ...

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