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Browsing by Author "Kameswara Rao, N"

Browsing by Author "Kameswara Rao, N"

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  • A photoionization model of the nebula around the WC11 star M4-18 
    Surendiranath, R; Kameswara Rao, N (Blackwell Publishing, 1995-08)
    A photoionization code has been developed incorporating provision for the presence of dust mixed with gas. M4-18 has been modelled utilizing optical CCD spectra and other observations ranging from UV to radio wavelengths. ...
  • Photometric and polarimetric observations of the Rv-tauri star Ar-Puppis 
    Raveendran, A. V; Kameswara Rao, N (Springer, 1988)
  • Photometric and radial velocity variations of RCrB near maximum light 
    Raveendran, A. V; Ashoka, B. N; Kameswara Rao, N (D. Reidel Publishing Co, 1986)
    Fourier analysis of the light curves of R CrB in the V band near maximum shows that in addition to several significant short periods there is a modulation of the visual light with a period around 1170 days, similar to that ...
  • Planetary nebulae with UVIT II. Revelations from far-UV vision of Butterfly nebula NGC 6302 
    Kameswara Rao, N; De Marco, O; Sriram, K; Murthy, J; Ray, A; Sutaria, F. K; Mohan, Rekhesh (EDP Sciences, 2018-12)
    The high excitation planetary nebula, NGC 6302, has been imaged in two far-ultraviolet (FUV) filters, F169M (Sapphire; λeff: 1608 Å)and F172M (Silica; λeff: 1717 Å) and two near-UV (NUV) filters, N219M (B15; λeff: 2196 Å) ...
  • Planetary nebulae with UVIT: A progress report 
    Kameswara Rao, N; Sutaria, F; Murthy, J; Ray, A; Pandey, G (Indian Academy of Sciences, 2021-10)
    The spectral region between 1250–3000 A contains important spectral lines to understand the ˚ morphological structures and evolution of planetary nebulae. This is the region sampled by UVIT through various filter bands ...
  • Planetary nebulae with UVIT: Far ultra-violet halo around the Bow Tie nebula (NGC 40) 
    Kameswara Rao, N; Sutaria, F. K; Murthy, J; Sriram, K; Mohan, Rekhesh; Ray, A (EDP Sciences, 2018-01)
    Context. NGC 40 is a planetary nebula with diffuse X-ray emission, suggesting an interaction of the high-speed wind from WC8 cen- tral star (CS) with the nebula. It shows strong C IV 1550 Å emission that cannot be ...
  • Polarimetric observations of hydrogen deficient stars 
    Raveendran, A. V; Kameswara Rao, N; Deshpande, M. R; Joshi, U. C; Kulshrestha, A. K (Reidel Publishing Company, 1986)
    Polarimetric observations of HD 30353, SU Tau, XX Cam, R CrB, UV Cas, BD +13°3224, BD +10°2179 and HD 124448 are presented. The linear polarization of HD 30353 is found to vary appreciably at Hα over a time scale as short ...
  • Polarimetric observations of the RV Tauri star AR Puppis 
    Raveendran, A. V; Kameswara Rao, N (European Southern Observatory, 1988-03)
    UBVRI polarimetry of AR Pup is presented. Large variations are seen both in the amount and direction of polarization. On one occasion, the polarization in U was found to be as high as 14.6 percent. Polarization level ...
  • Polarimetric study of the RV Tauri star AC Herculis 
    Raveendran, A. V; Kameswara Rao, N; Anandaram, M. N (Astronomical Society of Indian, 1989-09)
    BVRI polarimetry of AC Her shows that the wavelength dependence of polarization is weak with a marginal increase towards blue and that the position angle is nearly independent of wavelength. It is argued that the interstellar ...
  • Polarimetry of Comet P/Halley - Properties of dust 
    Sen, A. K; Deshpande, M. R; Joshi, U. C; Kameswara Rao, N; Raveendran, A. V (European Southern Observatory, 1991-02)
    Comet P/Halley was observed polarimetrically for seven nights in IHW and other continuum filters, during its pre- and postpreihelion passages. These polarimetric observations have been combined with the observations taken ...
  • Preliminary analysis of the broad he i emission lines in R CrB 
    Surendiranath, R; Rangarajan, K. E; Kameswara Rao, N (D. Reidel Publishing Co, 1986)
  • Presence of Mg II emission in R Coronae Borealis at maximum light 
    Kameswara Rao, N; Nandy, K; Bappu, M. K. V (Royal Astronomical Society, 1981-06)
    The high dipersion spectrum of R CrB in the long wavelength obtained near its maximum with the International Ultraviolet Explorer shows the presence of chromospheric Mg II emission. For comparison the spectrum of Gamma Cyg ...
  • Probing circumstellar dust formation through high resolution spectroscopy 
    Kameswara Rao, N (Astronomical Society of India, 2005-06)
    The existence of cool regions where dust can condense is explored in RCB stars at minimum
  • R Coronae Borealis at the 2003 light minimum 
    Kameswara Rao, N; Lambert, D. L; Shetrone, M. D (Blackwell Publishing, 2006-08)
    A set of five high-resolution optical spectra of R CrB obtained in 2003 March is discussed. At the time of the first spectrum (March 8), the star was at V = 12.6, a decline of more than six magnitudes. By March 31, the ...
  • The R Coronae Borealis stars - A few mere facts 
    Lambert, D. L; Kameswara Rao, N (Indian Academy of Sciences, 1994-03)
    This review presents a selection of recent highlights of observations of R Coronae Borealis (RCB) variables. Emphasis is placed on an abundance analysis of a complete sample (18 stars) of the warm galactic RCBs. It is shown ...
  • The R Coronae Borealis stars - atmospheres and abundances 
    Asplund, M; Gustafsson, B; Lambert, D. L; Kameswara Rao, N (European Southern Observatory, 2000-01)
    An abundance analysis of the H-deficient and He- and C-rich R Coronae Borealis (R CrB) stars has been undertaken to examine the ancestry of the stars. The investigation is based on high-resolution spectra and line-blanketed ...
  • R Coronae Borealis stars at minimum light - UW Cen 
    Kameswara Rao, N; Reddy, B. E; Lambert, D. L (Blackwell Publishing, 2004-12)
    Two high-resolution optical spectra of the R Coronae Borealis (R CrB) star UW Cen in decline are discussed. A spectrum from mid-1992 when the star had faded by 3 mag shows just a few differences with the spectrum at maximum ...
  • The R Coronae Borealis stars: carbon abundances from forbidden carbon lines 
    Pandey, G; Lambert, D. L; Kameswara Rao, N; Gustafsson, B; Ryde, N; Yong, D (Royal Astronomical Society, 2004-09)
    Spectra of several R Coronae Borealis (RCB) stars at maximum light have been examined for the [CI] 9850- and 8727-Åabsorption lines. The 9850-Åline is variously blended with an FeII and CN lines, but positive identifications ...
  • Reddening and dust distribution around V348 SGR 
    Kameswara Rao, N; Nandy, K (Bruxelles : Palais des Académies, 1988)
    Radio and Brackett gamma observations indicate large value of reddening E(B - V) = 1.5 to the nebula surrounding V348 Sgr, where as the star appears to be reddened by only E(B - V) is approximately 0.4. The infrared ...
  • SALT revisits DY Cen: a rapidly evolving strontium-rich single helium star 
    Jeffery, C. S; Kameswara Rao, N; Lambert, D. L (Oxford University Press on behalf of the Royal Astronomical Society, 2020-04)
    The hydrogen-deficient star DY Cen has been reported as an R CrB-type variable, an extreme helium star (with some hydrogen), and as a single-lined spectroscopic binary. It has been associated with a dramatic change in ...

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