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Browsing IIAP Publications by Title

Browsing IIAP Publications by Title

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  • 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 ...
  • V1647 Orionis 
    Ojha, D. K; Ghosh, S. K; Kaurav, S. S; Bhatt, B. C; Sahu, D. K; Tej, A (International Astronomical Union, 2008-12)
  • V2676 Oph: Estimating Physical Parameters of a Moderately Fast Nova 
    Raj, A; Pavana, M; Kamath, U. S; Anupama, G. C; Walter, F. M (Copernicus Foundation for Polish Astronomy, 2018-03)
    Using our previously reported observations, we derive some physical parameters of the moderately fast nova V2676 Oph 2012 #1. The best-fit CLOUDY model of the nebular spectrum obtained on 2015 May 8 shows a hot white dwarf ...
  • V899 Mon: an outbursting protostar with a peculiar light curve, and its transition phases 
    Ninan, J. P; Ojha, D. K; Baug, T; Bhatt, B. C; Mohan, V; Ghosh, S. K; Menshchikov, A; Anupama, G. C; Tamura, M; Henning, Th (IOP Publishing, 2015-12-10)
    We present a detailed study of V899 Mon (a new member in the FUors/EXors family of young low-mass stars undergoing outburst), based on our long-term monitoring of the source starting from 2009 November to 2015 April. Our ...
  • Valence universal multireference coupled cluster calculations of the properties of indium in its ground and excited states 
    Madhulita Das; Chaudhuri, R. K; Chattopadhyay, S; Mahapatra, U. S (IOP Publishing, 2011-03)
    In view of its importance in high precision spectroscopy, the valence universal multireference coupled cluster (VU-MRCC) method with four-component relativistic spinors has been applied to compute ionization potential (IP) ...
  • Validation of estimated cloud fraction from MERRA-2 and AIRS data using ground based observation over IAO, Hanle 
    Shantikumar, S. N; Narendra, A; Bhatt, B. C; Prabhu, T. P; Anupama, G. C; Angchuk, D; Jorphail, S (Elsevier B.V, 2020-08-15)
    We report for validation of cloud fraction estimated from high-resolution (hourly) data from MERRA-2 and AIRS instrument aboard NASA’s Aqua satellite during its ascending and descending orbits with hourly ground-based ...
  • Validation of water vapor retrieval from Moderate Resolution Imaging Spectro-radiometer (MODIS) in near infrared channels using GPS data over IAO-Hanle, in the trans-Himalayan region 
    Shantikumar, N. S; Jade, S; Shrungeshwara, T. S; Song, H.-J (Elsevier B.V, 2016-01)
    Integrated precipitable water vapor (PWV) retrieved from Moderate Resolution Imaging Spectro-radiometer (MODIS) in near-infrared channels is examined with the PWV estimated from the Global Positioning System (GPS) data and ...
  • Variability and the Size–Luminosity Relation of the Intermediate-mass AGN in NGC 4395 
    Cho, Hojin; Woo, Jong-Hak; Hodges-Kluck, E; Son, Donghoon; Shin, Jaejin; Gallo, Elena; Bae, Hyun-Jin; Brink, T. G; Cho, Wanjin; Filippenko, A. V; Horst, J. C; Ilic, Dragana; Joner, M. D; Kang, Daeun; Kang, Wonseok; Kaspi, Shai; Kim, Taewoo; Kovacevic, A. B; Kumar, S; Le, Huynh Anh N; Nadzhip, A. E; Nunez, F. P; Metlov, V. G; Oknyansky, V. L; Park, Songyoun; Popovic, L. C; Rakshit, S; Schramm, M; Shatsky, N. I; Spencer, M; Sung, E.-H; Sung, H.-i; Tatarnikov, A. M; Vince, O (IOP Publishing, 2020-04-01)
    We present a variability study of the lowest-luminosity Seyfert 1 nucleus of the galaxy NGC 4395 based on photometric monitoring campaigns in 2017 and 2018. Using 22 ground-based and space telescopes, we monitored NGC ...
  • The variability of HD 76536 
    Shylaja, B. S (Kluwer Academic Publishers, 1990-02)
    The spectrophotometric and photometric observations of the WC star HD 76536 are reported. The flux and the magnitude variations appear to be periodic. The possibilities of a compact binary are discussed.
  • Variability of sunspot cycle QBO and total ozone over high altitude Western Himalayan regions 
    Shantikumar, N. S (Elsevier B.V., 2011-10)
    Long-term trend of total column ozone at high altitude region in Ladakh is studied, using a total ozone mapping spectrometer and an ozone monitoring instrument during 1979–2008. In the region, total ozone exhibits seasonality ...
  • Variability of the solar chromospheric network over the solar cycle 
    Kariyappa, R; Sivaraman, K. R (Springer, 1994-06)
    From a large sample of the Kodaikanal spectroheliograms in the Ca II K line we have studied the variations in the intensity of the network elements over two solar cycles and have estimated their contribution to the overall ...
  • Variable circumstellar activity of V351 Orionis 
    Choudhury, R; Bhatt, H. C; Pandey, G (EDP Sciences, 2011-02)
    Context. Emission and absorption line profiles which are formed in the interaction of pre-main sequence stars and their circumstellar environment are found to be variable at various timescales. Aims. We investigate the ...
  • Variable mass accretion and failed wind explain changing-look phenomena in NGC 1365 
    Mondal, Santanu; Adhikari, T. P; Hryniewicz, K; Stalin, C. S; Pandey, Ashwani (EDP Sciences, 2022-06)
    Changing-look active galactic nuclei (CLAGNs) show a complex nature in their X-ray spectral shape and line-of-sight column-density variation. The physical mechanisms responsible for these variations are unclear. Here, we ...
  • THE VARIABLE STAR POPULATION IN THE GLOBULAR CLUSTER NGC 6934 
    Yepez, M. A; Ferro, A. A; Muneer, S; Giridhar, S (Instituto de Astronomia, 2018-04)
    We report an analysis of new V and I CCD time-series photometry of the globular cluster NGC 6934. Through the Fourier decomposition of the RR Lyrae light curves the mean values of [Fe/H] and the distance of the cluster ...
  • Variable stars in M37 
    Dar, A. A; Parihar, P. S; Saleh, P; Malik, M. A (IOP Publishing, 2018-12)
    The CCD photometric observations of open star cluster M37 (NGC 2099) were carried out up to a limiting magnitude of V ~ 20 in both B and V filters to search for variable stars using a 2k × 4k CCD and the 1.3 m telescope ...
  • Variable stars in NGC 4147 revisited: RR Lyrae stars new CCD VI photometry and physical parameters 
    Arellano Ferro, A; Rojas Galindo, F. C; Muneer, S; Giridhar, S (Universidad Nacional Autonoma De Mexico, 2018-10)
    We have calculated the physical parameters of the RR Lyrae stars in the globular cluster NGC 4147 via the Fourier decomposition of their light curves, using new data and well-established semi-empirical calibrations and ...
  • Variable stars in Palomar 13; an evaporating globular cluster 
    Yepez, M. A; Ferro, A. A; Schoeder, K. P; Muneer, S; Giridhar, S; Allen, C (Elsevier B.V, 2019-08)
    We present new CCD VI photometry of the distant globular cluster Pal 13. Fourier decomposition of the light curves of the three cluster member RRab stars lead to estimations of [Fe/H] = −1.65, and a distance of 23.67 ± ...
  • Variable Stars in Palomar 13; an Evaporating Globular Cluster 
    Yepez, M. A; Ferro, A. Arellano; Schröder, K. P.; Muneer, S; Giridhar, Sunetra; Allen, Christine (Astronomical Society of the Pacific, 2021-06)
    We present new CCD VI photometry of the globular cluster Pal 13. Fourier decomposition of the light curves of RRab stars lead to estimations of [Fe/H]ZW = -1.65±0.15, and a distance to the cluster of 23.67±0.57 kpc. A ...
  • Variable Stars in the Globular Cluster NGC 288: [Fe/H] and Distance 
    Ferro, A. A; Bramich, D.M; Giridhar, S; Jaimes, R. F; Kains, N; Kuppuswamy, K (Copernicus Foundation for Polish Astronomy, 2013-12)
    A search for variable stars in the globular cluster NGC 288 was carried out using a time-series of CCD images in the V and I filters. The photometry of all stellar sources in the field of view of our images, down to V≈19 ...
  • Variable stars in the globular cluster NGC 7492. New discoveries and physical parameter determination 
    Figuera Jaimes, R; Arellano Ferro, A; Bramich, D. M; Giridhar, S; Kuppuswamy, K (EDP Sciences, 2013-08)
    Aims. We have performed a photometric V,R,I CCD time-series analysis with a baseline of about eight years of the outer-halo globular cluster NGC 7492 with the aim of searching for new variables and using these (and the ...

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