IIA Institutional Repository

Browsing by Author "Sivarani, T"

Browsing by Author "Sivarani, T"

Sort by: Order: Results:

  • Spectroscopy of HD 168625 (IRAS 18184-1623) 
    García, L. P; Sivarani, T; Parthasarathy, M; Manchado, A (Kluwer Academic Publishers, 2001-08)
    HD 168625 (B9-A0 Ia) was classified as a post-AGB star and also as a luminous blue variable. We have analysed the high resolution optical spectra of HD 168625 and derived the atmospheric parameters and the chemical ...
  • Spectroscopy of post-AGB a-supergiant HD 101584 (IRAS 11385-5517) 
    Sivarani, T; Parthasarathy, M; García, L. P; Manchado, A; Pottasch, S. R (Kluwer Academic Publishers, 2001-08)
    In the high resolution optical spectra we identified forbidden lines of [OI] and [CI], which indicate the presence of low excitation nebula. There are many emission lines due forbidden and permitted lines of neutral and ...
  • Spectroscopy of post-AGB candidate HD 331319 (IRAS 19475+3119) 
    Sivarani, T; Parthasarathy, M; García, L. P; Manchado, A (Kluwer Academic Publishers, 2001-08)
    HD 331319 is a F3 Ib star with a detached cold circumstellar dust shell with far-IR colours similar to planetary nebulae. From an analysis of high resolution spectra using LTE stellar atmospheric models, we have derived ...
  • Spectroscopy of post-AGB candidate IRAS 10215-5916 
    Sivarani, T; Parthasarathy, M; García, L. P; Manchado, A (Kluwer Academic Publishers, 2001-08)
    IRAS 10215-5916 was classified as a post-AGB star and also as a massive red supergiant. It was also found to be a spectroscopic binary. In our high resolution spectra we found molecular features from a cool star of Teff = ...
  • Spectroscopy of the post-AGB star HD 101584 (IRAS 11385-5517) 
    Sivarani, T; Parthasarathy, M; García-Lario, P; Manchado, A; Pottasch, S. R (The European Southern Observatory, 1999-06)
    From an analysis of the spectrum (4000 Ä to 8800 Ä) of HD 101584 it is found that most of the neutral and single ionized metallic lines are in emission. The forbidden emission lines of [OI] 6300 Ä and 6363 Ä and [CI] 8727 ...
  • The Stability of Fiber Spectrographs in the Faint-source Regime 
    Bundy, Kevin; Law, David; MacDonald, Nick; Westfall, Kyle B.; Sivarani, T; Divakar, Devika; Bershady, Matthew; Gu, Meng; Yan, Renbin; Roy, Namrata; Poppett, Claire; Drory, Niv (American Astronomical Society, 2022-09-01)
    The use of optical fibers in astronomical instrumentation offers high-multiplex and light-gathering flexibility. However, with most previous fiber spectrographs optimized for large fields of view on modest-aperture telescopes, ...
  • Stellar Relics from the Early Galaxy 
    Sivarani, T (Indian Academy of Sciences, 2013-03)
    We reviewed the recent progress in the field of stellar/galactic archeology, which is a study of the relics from the early galaxy. The oldest and most pristine objects that can be observed in the galaxy are the low mass ...
  • Target selection for the SDSS-III marvels survey 
    Paegert, M; Stassun, K. G; De Lee, N; Pepper, J; Fleming, S. W; Sivarani, T; Mahadevan, S; Mack, C. E; Dhital, S; Hebb, L; Ge, J (IOP Publishing, 2015-06)
    We present the target selection process for the Multi-object APO Radial Velocity Exoplanets Large-area Survey (MARVELS), which is part of the Sloan Digital Sky Survey (SDSS) III. MARVELS is a medium-resolution (R ∼ 11,000) ...
  • The TESS-Keck Survey. VIII. Confirmation of a Transiting Giant Planet on an Eccentric 261 Day Orbit with the Automated Planet Finder Telescope 
    Dalba, Paul A; Kane, Stephen R; Dragomir, Diana; Villanueva Jr, Steven; Collins, Karen A; Jacobs, Thomas Lee; LaCourse, Daryll M; Gagliano, Robert; Kristiansen, Martti H; Omohundro, Mark; Schwengeler, Hans M; Terentev, Ivan A; Vanderburg, Andrew; Fulton, Benjamin; Isaacson, Howard; Zandt, Judah Van; Howard, Andrew W; Thorngren, Daniel P; Howell, Steve B; Batalha, Natalie M; Chontos, Ashley; Crossfield, Ian J. M; Dressing, Courtney D.; Huber, Daniel; Petigura, Erik A.; Robertson, Paul; Roy, Arpita; Weiss, Lauren M; Behmard, Aida; Beard, Corey; Brinkman, Casey L; Giacalone, Steven; Hil, Michelle L; Lubin, Jack; Mayo, Andrew W; Mocnik, Teo; Murphy, Joseph M. Akana; Polanski, Alex S; Rice, Malena; Rosenthal, Lee J; Rubenzahl, Ryan A; Scarsdale, Nicholas; Turtelboom, Emma V; Tyler, Dakotah; Benni, Paul; Boyce, Pat; Esposito, Thomas M; Girardin, E; Laloum, Didier; Lewin, Pablo; Mann, Christopher R; Marchis, Franck; Schwarz, Richard P; Srdoc, Gregor; Steuer, Jana; Sivarani, T; Athira Unni; Eisner, Nora L; Fetherolf, Tara; Li, Zhexing; Yao, Xinyu; Pepper, Joshua; Ricker, George R.; Vanderspek, Roland; Latham, David W; Seager, S.; Winn, Joshua N; Jenkins, Jon M; Burke, Christopher J; Eastman, Jason D; Lund, Michael B; Rodriguez, David R; Rowden, Pamela; Ting, Eric B; Villaseñor, Jesus Noel (American Astronomical Society, 2022-02-01)
    We report the discovery of TOI-2180 b, a 2.8 MJ giant planet orbiting a slightly evolved G5 host star. This planet transited only once in Cycle 2 of the primary Transiting Exoplanet Survey Satellite (TESS) mission. Citizen ...
  • Towards the development of the Infrared Guide Star Catalogue for the adaptive optics observations by the Thirty Meter Telescope 
    Shah, Sarang; Subramanian, S; Anupama, G. C; Delgado, Francisco; Gillies, Kim; Maheswar, G; Narayanan, Rajalakshmi; Ramaprakash, A. N; Rao, Suhasini; Reddy, B. E; Skidmore, Warren; Sivarani, T; Subramaniam, A (SPIE-The International Society for Optical Engineering, 2022-08)
    At first light, the NIR instruments of TMT will be assisted by a multi-conjugate adaptive optics instrument, known as the Narrow Field Infrared Adaptive Optics System (NFIRAOS). NFIRAOS will use laser guide stars for ...
  • UVIT observation of Milky Way satellite galaxy Reticulum II 
    Divakar, D. K; Sivarani, T; Doddamani, V. H (Indian Academy of Sciences, 2021-10)
    We present the UV photometry of one of the Ultra-Faint Dwarf (UFD) Milky Way (MW) satellite galaxies, Reticulum II, using images acquired with the Ultra-Violet Imaging Telescope (UVIT) onboard AstroSat. Reticulum II is ...
  • Very low mass stellar and substellar companions to solar-like stars from MARVELS. II. A short-period companion orbiting an F star with evidence of a stellar tertiary and significant mutual inclination 
    Scott, W. F; Jian, G; Rory, B; Thomas, G. T; Justin, R. C; Nathan, D. L; Massimiliano, E; Bruno, F; Leticia, F; Bruce, G; Scott, G. B; Luan, G; Jonay, I. G. H; Leslie, H; Peng, J; Brian, L; Ben, N; Gustavo, F. P. M; Benjamin, J. S; Keivan, S; Todd, A. T; Benjamin, M. T; John, P. W; Michael, W. V. W; Eric, A; Carlos, A. P; Dmitry, B; Howard, B; Phillip, A. C; Louis, C; Korena, S. C; Luis, N. C; Melanie, L. G; Nelson, H; Stephen, R. K; Gary, R. L; Jian, L; Bo, M; Suvrath, M; Marcio, A. G. M; Elena, M; Viktor, M; Demitri, M; Duy Cuong, N; Daniel, O; Martin, P; Kaike, P; Joshua, P; Rafael, R; Eric, J. R; Basilio, X. S; Donald, P. S; Alaina, S; Audrey, S; Sivarani, T; Stephanie, S; Chelsea, L. M. V; Xiaoke, W; Ji, W; Benjamin, A. W; Gwendolyn, M. W; Bo, Z (IOP Publishing, 2012-09)
    We report the discovery via radial velocity (RV) measurements of a short-period (P = 2.430420±0.000006 days) companion to the F-type main-sequence star TYC 2930-00872-1. A long-term trend in the RV data also suggests the ...
  • Very Low Mass Stellar and Substellar Companions to Solar-like Stars from MARVELS. IV. A Candidate Brown Dwarf or Low-mass Stellar Companion to HIP 67526 
    Jiang, P; Ge, J; Cargile, P; Crepp, J. R; De Lee, N; Porto de Mello, G. F; Esposito, M.; Ferreira, L. D; Femenia, B; Fleming, S. W; Gaudi, B. S; Ghezzi, L; Gonzalez Hernandez, J. I; Hebb, L; Lee, B. L; Ma, Bo; Stassun, K. G; Wang, Ji; Wisniewski, John P; Agol, Eric; Bizyaev, Dmitry; Brewington, Howard; Chang, Liang; Nicolaci da Costa, Luiz; Eastman, Jason D; Ebelke, Garrett; Gary, Bruce; Kane, Stephen R; Li, Rui; Liu, Jian; Mahadevan, Suvrath; Maia, Marcio A. G; Malanushenko, Viktor; Malanushenko, Elena; Muna, Demitri; Nguyen, Duy Cuong; Ogando, Ricardo L. C; Oravetz, Audrey; Oravetz, Daniel; Pan, Kaike; Pepper, Joshua; Paegert, Martin; Allende Prieto, Carlos; Rebolo, Rafael; Santiago, Basilio X; Schneider, Donald P; Shelden Bradley, Alaina C; Sivarani, T; Snedden, Stephanie; van Eyken, J. C; Wan, Xiaoke; Weaver, Benjamin A; Zhao, Bo (IOP Publishing, 2013-09)
    We report the discovery of a candidate brown dwarf (BD) or a very low mass stellar companion (MARVELS-5b) to the star HIP 67526 from the Multi-object Apache point observatory Radial Velocity Exoplanet Large-area Survey ...
  • Very-Low-Mass Stellar and Substellar Companions to Solar-Like Stars From Marvels. III. A Short-period Brown Dwarf Candidate Around An Active GOIV Subgiant 
    Ma, Bo; Ge, J; Barnes, R; Crepp, J. R; De Lee, N; Dutra-Ferreira, L; Esposito, M; Femenia, B; Fleming, S. W; Gaudi, B. S; Ghezzi, L; Hebb, L; Gonzalez Hernandez, J. I; Lee, B. L; Porto de Mello, G. F; Stassun, K. G; Wang, J; Wisniewski, J. P; Agol, E; Bizyaev, D; Cargile, P; Chang, L; Nicolaci da Costa, L; Eastman, J. D; Gary, B; Jiang, P; Kane, S. R; Li, R; Liu, J; Mahadevan, S; Maia, M. A. G; Muna, D; Nguyen, D. C; Ogando, R. L. C; Oravetz, D; Pepper, J; Paegert, M; Prieto, C. A; Rebolo, R; Santiago, B. X; Schneider, D. P; Shelden, A; Simmons, A; Sivarani, T; van Eyken, J. C; Wan, X; Weaver, B. A; Zhao, Bo (IOP Publishing, 2013-01)
    We present an eccentric, short-period brown dwarf candidate orbiting the active, slightly evolved subgiant star TYC 2087-00255-1, which has effective temperature T eff = 5903 ± 42 K, surface gravity log (g) = 4.07 ± 0.16 ...
  • X-ray spectrum of NGC 3783 - Detection of soft excess and an emission line 
    Ghosh, K. K; Soundararajaperumal, S; Kalai Selvi, M; Sivarani, T (EDP Sciences, 1992-02)
    Results of the X-ray (0.1-10 keV) spectral analysis of the Seyfert I galaxy, NGC 3783, which was observed with EXOSAT on three epochs between 1983 and 1985, are presented here. No low energy absorption, intrinsic to the ...

Search DSpace

Browse

My Account