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Browsing IIAP Publications by Author "Sahu, D. K"

Browsing IIAP Publications by Author "Sahu, D. K"

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  • Discovery and rapid follow-up observations of the unusual type II SN 2018ivc in NGC 1068 
    Bostroem, K. A; Valenti, S; Sand, D. J; Andrews, J. E; Van Dyk, S. D; Galbany, L; Pooley, D; Amaro, R. C; Smith, N; Yang, S; Anupama, G. C; Arcavi, I; Baron, E; Brown, P. J; Burke, J; Cartier, R; Hiramatsu, D; Dastidar, R; DerKacy, J. M; Dong, Y; Egami, E; Ertel, S; Filippenko, A. V; Fox, O. D; Haislip, J; Hosseinzadeh, G; Howell, D. A; Gangopadhyay, A; Jha, S. W; Kouprianov, V; Kumar, B; Lundquist, M; Milisavljevic, D; McCully, C; Milne, P; Misra, K; Reichart, D. E; Sahu, D. K; Sai, H; Singh, A; Smith, P. S; Vinko, J; Wang, X; Wang, Y; Wheeler, J. C; Williams, G. G; Wyatt, S; Zhang, J; Zhang, X (IOP Publishing, 2020-05-20)
    We present the discovery and high-cadence follow-up observations of SN 2018ivc, an unusual SNe II that exploded in NGC 1068 (D = 10.1 Mpc). The light curve of SN 2018ivc declines piecewise-linearly, changing slope ...
  • Discovery of Dramatic Optical Variability in SDSS J1100+4421: A Peculiar Radio-loud Narrow-line Seyfert 1 Galaxy? 
    Tanaka, M; Morokuma, T; Itoh, R; Akitaya, H; Tominaga, N; Saito, Y; Stawarz, L; Tanaka, Y, T; Gandhi, P; Ali, G; Aoki, T; Contreras, C; Doi, M; Essam, A; Hamed, G; Hsiao, E. Y; Iwata, I; Kawabata, K. S; Kawai, N; Kikuchi, Y; Kobayashi, N; Kuroda, D; Maehara, H; Matsumoto, E; Mazzali, P. A; Minezaki, T; Mito, H; Miyata, T; Miyazaki, S; Mori, K; Moritani, Y; Morokuma-Matsui, Kana; Morrell, N; Nagao, T; Nakada, Y; Nakata, F; Noma, C; Ohsuga, K; Okada, N; Phillips, M. M; Pian, E; Richmond, M. W; Sahu, D. K; Sako, S; Sarugaku, Y; Shibata, T; Soyano, T; Stritzinger, M. D; Tachibana, Y; Taddia, F; Takaki, K; Takey, Ali; Tarusawa, K; Ui, T; Ukita, N; Urata, Y; Walker, E. S; Yoshii, T (IOP Publishing, 2014-10-01)
    We present our discovery of dramatic variability in SDSS J1100+4421 by the high-cadence transient survey Kiso Supernova Survey. The source brightened in the optical by at least a factor of three within about half a day. ...
  • Discovery of Main-belt Comet P/2006 VW139 by Pan-STARRS1 
    Hsieh, H. H; Yang, Bin; Haghighipour, N; Kaluna, H. M; Fitzsimmons, A; Denneau, L; Novakovic, B; Jedicke, R; Wainscoat, R. J; Armstrong, J. D; Duddy, S. R; Lowry, S. C; Trujillo, C. A; Micheli, M; Keane, J. V; Urban, L; Riesen, T; Meech, K. J; Abe, S; Cheng, Yu-Chi; Chen, Wen-Ping; Granvik, M; Grav, T; Ip, Wing-Huen; Kinoshita, D; Kleyna, J; Lacerda, P; Lister, T; Milani, A; Tholen, D. J; Vereš, P; Lisse, C. M; Kelley, M. S; Fernández, Y. R; Bhatt, B. C; Sahu, D. K; Kaiser, N; Chambers, K. C; Hodapp, K. W; Magnier, E. A; Price, P. A; Tonry, J. L (IOP Publishing, 2012-03-20)
    The main-belt asteroid (300163) 2006 VW139 (later designated P/2006 VW139) was discovered to exhibit comet-like activity by the Pan-STARRS1 (PS1) survey telescope using automated point-spread-function analyses performed ...
  • Disintegration of active asteroid P/2016 G1 (PANSTARRS) 
    Hainaut, O. R; Kleyna, J. T; Meech, K. J; Boslough, Mark; Micheli, Marco; Wainscoat, Richard; Dela Cruz, Marielle; Keane, J. V; Sahu, D. K; Bhatt, B. C (EDP Sciences, 2019-08)
    We report on the catastrophic disintegration of P/2016 G1 (PANSTARRS), an active asteroid, in April 2016. Deep images over three months show that the object is made up of a central concentration of fragments surrounded by ...
  • Early optical and millimeter observations of GRB 030226 afterglow 
    Pandey, S. B; Sagar, R; Anupama, G. C; Bhattacharya, D; Sahu, D. K; Castro-Tirado, A. J; Bremer, M (EDP Sciences, 2004-04)
    The CCD magnitudes in Johnson UBV and Cousins RI photometric passbands for the afterglow of the long duration GRB 030226 are presented. Upper limits of a few mJy to millimeter wave emission at the location of optical are ...
  • EPOXI: Comet 103P/Hartley 2 Observations from a Worldwide Campaign 
    Meech, K. J and 194 coauthors; Bhatt, B. C; Sahu, D. K (IOP Publishing, 2011-06-10)
    Earth- and space-based observations provide synergistic information for space mission encounters by providing data over longer timescales, at different wavelengths and using techniques that are impossible with an in situ ...
  • ESC observations of SN 2005cf – I. Photometric evolution of a normal Type Ia supernova 
    Pastorello, A; Taubenberger, V; Elias-Rosa, N; Mazzali, P. A; Pignata, G; Cappellaro, E; Garavini, G; Nobili, S; Anupama, G. C; Bayliss, D. D. R; Benetti, S; Bufano, F; Chakradhari, N. K; Kotak, R; Goobar, A; Navasardyan, H; Patat, F; Sahu, D. K; Salvo, M; Schmidt, B. P; Stanishev, V; Turatto, M; Hillebrandt, W (Blackwell Publishing, 2007-04)
    We present early-time optical and near-infrared photometry of supernova (SN) 2005cf. The observations, spanning a period from about 12 d before to 3 months after maximum, have been obtained through the coordination of ...
  • Estimating the parameters of globular cluster M 30 (NGC 7099) from time-series photometry 
    Kains, N; Bramich, D. M; Ferro, A. A; Jaimes, R. F; Jorgensen, U. G; Giridhar, S; Penny, M. T; Alsubai, K. A; Andersen, J. M; Bozza, V; Browne, P; Burgdorf, M; Novati, S. C; Damerdji, Y; Diehl, C; Dodds, P; Dominik, M; Elyiv, A; Fang, X.-S; Giannini, E; Gu, S.-H; Hardis, S; Harpsoe, K; Hinse, T. C; Hornstrup, A; Hundertmark, M; Jessen-Hansen, J; Juncher, D; Kerins, E; Kjeldsen, H; Korhonen, H; Liebig, C; Lund, M. N; Lundkvist, M; Mancini, L; Martin, R; Mathiasen, M; Rabus, M; Rahvar, S; Ricci, D; Sahu, D. K; Scarpetta, G; Skottfelt, J; Snodgrass, C; Southworth, J; Surdej, J; Tregloan-Reed, J; Vilela, C; Wertz, O; Williams, A (EDP Sciences, 2013-07)
    Aims. We present the analysis of 26 nights of V and I time-series observations from 2011 and 2012 of the globular cluster M 30 (NGC 7099). We used our data to search for variable stars in this cluster and refine the periods ...
  • The Evolution of the Peculiar Type Ia Supernova SN 2005hk over 400 Days 
    Sahu, D. K; Tanaka, M; Anupama, G. C; Kawabata, K. S; Maeda, K; Tominaga, N; Nomoto, K; Mazzali, P. A; Prabhu, T. P (The American Astronomical Society, 2008-06-10)
    UBVRI photometry and medium-resolution optical spectroscopy of the peculiar Type Ia supernova SN 2005hk are presented and analyzed, covering the premaximum phase to around 400 days after explosion. The supernova is found ...
  • Evolution of the Type IIb SN 2011fu 
    Pandey, S. B; Kumar, B; Sahu, D. K; Vinko, J; Moskvitin, A. S; Anupama, G. C; Bhatt, V. K; Ordasi, A; Nagy, A; Sokolov, V. V; Sokolova, T. N; Komarova, V. N; Kumar, B; Bose, S; Roy, R; Sagar, R (Cambridge University Press, 2014-01)
    The UBVRI photometric follow-up of SN 2011fu has been initiated a few days after the explosion, shows a rise followed by steep decay in all bands and shares properties very similar to that seen in case of SN 1993J, with a ...
  • Exploring the optical behaviour of a Type Iax supernova SN 2014dt 
    Singh, M; Misra, K; Sahu, D. K; Dastidar, R; Gangopadhyay, A; Bose, S; Srivastav, S; Anupama, G. C; Chakradhari, N. K; Brajesh Kumar; Kumar, B; Pandey, S. B (Oxford University Press on behalf of the Royal Astronomical Society, 2018-02)
    We present optical photometric (up to ∼ 410 d since B max ) and spectroscopic (up to ∼ 157 d since B max ) observations of a Type Iax supernova (SN) 2014dt located in M61. SN 2014dt is one of the brightest and ...
  • Far-ultraviolet to Near-infrared Observations of SN 2023ixf: A High-energy Explosion Engulfed in Complex Circumstellar Material 
    Teja, Rishabh Singh; Singh, Avinash; Basu, Judhajeet; Anupama, G. C; Sahu, D. K; Dutta, Anirban; Swain, Vishwajeet; Nakaoka, Tatsuya; Pathak, Utkarsh; Bhalerao, Varun; Barway, Sudhanshu; Kumar, Harsh; Nayana, A. J; Imazawa, Ryo; Kumar, Brajesh; Kawabata, Koji S (American Astronomical Society, 2023-09-01)
    We present early-phase panchromatic photometric and spectroscopic coverage spanning the far-ultraviolet to near-infrared regime of the nearest hydrogen-rich core-collapse supernova (SN) in the last 25 yr, SN 2023ixf. We ...
  • The fast, luminous ultraviolet transient AT2018cow: extreme supernova, or disruption of a star by an intermediate-mass black hole? 
    Perley, D. A; Mazzali, P. A; Yan, Lin|; Cenko, S. Bradley; Gezari, Suvi; Taggart, Kirsty; Blagorodnova, Nadia; Fremling, Christoffer; Mockler, Brenna; Singh, A; Tominaga, Nozomu; Tanaka, Masaomi; Watson, Alan M; Ahumada, Tomas; Anupama, G. C; Ashall, Chris; Becerra, Rosa L; Bersier, David; Bhalerao, Varun; Bloom, Joshua S; Butler, Nathaniel R; Copperwheat, Chris; Coughlin, Michael W; De, Kishalay; Drake, Andrew J; Duev, Dmitry A; Frederick, Sara; Gonzalez, J. J; Goobar, Ariel; Heida, Marianne; Ho, Anna Y. Q; Horst, John; Hung, Tiara; Itoh, Ryosuke; Jencson, Jacob E; Kasliwal, Mansi M; Kawai, Nobuyuki; Khanam, Tanazza; Kulkarni, Shrinivas R; Brajesh Kumar; Harsh Kumar; Kutyrev, Alexander S; Lee, William H; Maeda, Keiichi; Ashish Mahabal; Murata, Katsuhiro L; Neill, James D; Ngeow, Chow-Choong; Penprase, Bryan; Pian, Elena; Quimby, Robert; Ramirez-Ruiz, Enrico; Richer, Michael G; Roman-Zuniga, Carlos G; Sahu, D. K; Srivastav, S; 9 others (Oxford University Press on behalf of the Royal Astronomical Society, 2019-03)
    Wide-field optical surveys have begun to uncover large samples of fast (trise ≲ 5 d), luminous (Mpeak < −18), blue transients. While commonly attributed to the breakout of a supernova shock into a dense wind, the great ...
  • Flash Ionization Signatures in the Type Ibn Supernova SN 2019uo 
    Gangopadhyay, A; Misra, K; Hiramatsu, D; Wang, Shan-Qin; Hosseinzadeh, G; Wang, Xiaofeng; Valenti, Stefano; Zhang, Jujia; Howel, D. A; Arcavi, Iair; Anupama, G. C; Burke, Jamison; Dastidar, Raya; Koichi Itagaki, Koichi; Kumar, Brajesh; Kumar, B; Li, Long; McCully, Curtis; Mo, Jun; Pandey, S. B; Pellegrino, Craig; Sa, Hanna; Sahu, D. K; Pankaj Sanwal; Singh, A; Singh, M; Zhang, Jicheng; Zhang, Tianmeng; Zhang, Xinhan (IOP Publishing, 2020-02-01)
    We present photometric and spectroscopic observations of the type Ibn supernova (SN) 2019uo, the second ever SN Ibn with flash ionization (He ii, C iii, N iii) features in its early spectra. SN 2019uo displays a rapid ...
  • A flattening in the optical light curve of SN 2002ap 
    Pandey, S. B; Anupama, G. C; Sagar, R; Bhattacharya, D; Sahu, D. K; Pandey, J. C (Royal Astronomical Society, 2003-04)
    We present the UBVRcIc broad-band optical photometry of the Type Ic supernova SN 2002ap obtained during 2002 February 6-March 23 in the early decline phases and also later on 2002 August 15. Combining these data with the ...
  • A Flattening in the Optical Light Curve of SN 2002ap. 
    Pandey, S. B; Anupama, G. C; Sagar, R; Bhattacharya, D; Sahu, D. K; Pandey, J. C (Blackwell Publishing, Edinburge, UK, 1994)
  • Four years of starspot evolution on an active F-type ultra-fast rotator KIC 6791060 
    Karmakar, Subhajeet; Pandey, J. C; Savanov, Igor S; Raj, A; Dmitrienko, E. S; Pakhomov, Yurij; Sahu, D. K (Cambridge University Press, 2018-02)
    Using the data obtained from Kepler satellite, we have analyzed an F-type ultra-fast rotator KIC 6791060. We derive a rotational period of 0.34365±0.00004 d. Multiple periodicity with a period separation of ∼0.00016 d was ...
  • Further evidence for intra-night optical variability of radio-quiet quasars 
    Goyal, Arti; Gopal-Krishna; Sagar, R; Anupama, G. C; Sahu, D. K (Astronomical Society of India, 2007-06)
    Although well established for BL Lac objects and radio-loud quasars, the occurrence of intra-night optical variability (INOV) in radio-quiet quasars is still debated, primarily since only a handful of INOV events with good ...
  • GRB 021004: Optical Observations 
    Sahu, D. K; Bhatt, B. C; Anupama, G. C; Prabhu, T. P (NASA, 2002)
  • GRB 051028: an intrinsically faint gamma-ray burst at high redshift? 
    Castro-Tirado, A. J; Jelínek, M; Pandey, S. B; McBreen, S; de Jong, J; Sahu, D. K; Ferrero, P; Caballero, J. A; Gorosabel, J; Kann, D. A; Klose, S; de Ugarte Postigo, A; Anupama, G. C; Gry, C; Guziy, S; Srividya, S; Valdivielso, L; Vanniarajan, S; Henden, A. A (EDP Sciences, 2006-12)
    We present multiwavelength observations of the gamma-ray burst GRB 051028 detected by HETE-2 in order to derive its afterglow emission parameters and to determine the reason for its optical faintness when compared to other ...

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