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Browsing by Author "Ashok, N. M"

Browsing by Author "Ashok, N. M"

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  • Fabry-Perot interferometric observations of the coronal red and green lines during the 1983 Indonesian eclipse 
    Chandrasekhar, T; Ashok, N. M; Desai, J. N; Pasachoff, J. M; Sivaraman, K. R (Optical society of America, 1984-02)
    A dual-channel Fabry-Perot interferometric system was used to study simultaneously the coronal emission lines at 5303 Å (Fe XIV) and at 6374 Å (Fe X). Initial results indicate an emission corona confined largely within 1.2 ...
  • High-resolution studies of forbidden O I and NH2 line emissions at 6300 A in Halley's comet 
    Prasad, C. D; Chandrasekhar, T; Desai, J. N; Ashok, N. M; Sivaraman, K. R; Rajmohan, R (Astronomical Society of the Pacific, 1988-06)
    The forbidden O I line and NH2 (0-8-0) emissions of Comet Halley at about 6300 A were observed during April 1986 using a Fabry-Perot spectrometer with a resolution of about 0.14 A. The forbidden O I line and NH2 rotational ...
  • Imaging Fabry-Perot observations of green coronal line during the total solar eclipse of 21 June 2001 
    Chandrasekhar, T; Ashok, N. M; Anandarao, B. G (Astronomical Society of India, 2002-09)
    A Fabry-Perot interferometric experiment on the Green Coronal line was successfully performed during the total solar eclipse of 21 June 2001 from Lusaka, Zambia. Use of a cooled CCD camera permitted 17 separate exposures ...
  • Infrared study of the first identified helium nova V445 Puppis 
    Ashok, N. M (Astronomical Society of India, 2005-06)
    The eruptive variable V445 Puppis has been proposed by us as the first observed Helium nova. The absence of hydrogen lines in the early optical spectra showed the peculiar nature of this object. We have observed V445 Pup ...
  • Insights into the evolution of symbiotic recurrent novae from radio synchrotron emission: V745 Scorpii and RS Ophiuchi 
    Kantharia, N. G; Dutta, P; Roy, N; Anupama, G. C; Ishwara-Chandra, C. H; Chitale, A; Prabhu, T. P; Banerjee, D. P. K; Ashok, N. M (Oxford University Press on behalf of the Royal Astronomical Society, 2016-02)
    We present observations at 610 and 235 MHz using the Giant Metrewave Radio Telescope (GMRT) of the recurrent nova V745 Scorpii which recorded its last outburst on 2014 February 6. This is the second symbiotic recurrent ...
  • IR observations of Am stars 
    Shylaja, B. S; Ashok, N. M (Astronomical Society of India, 2002)
    The IR observations of chemically peculiar stars are carried out and compared with the previous data in IR and far IR from IRAS. The flux redistribution appears to be a common phenomenon in all the stars of this class. The ...
  • IR Spectroscopy of Nova-like Sources 
    Banerjee, D. P. K; Ashok, N. M (Astronomical Society of India, 2003)
    Near - IR spectroscopic and photometric observations of the eruptive variables V838 Mon and V445 Puppis in the J H K bands are reported. These objects erupted in nova-like explosions but evolved into rather unique and ...
  • Is HR 2947 a variable? 
    Kameswara Rao, N; Ashok, N. M; Kulkarni, P. V (Astronomical Society of India, 1981-06)
    Observations of HR 2947 show that it is fainter by 0.3 mag in V compared to the magnitude listed by Cowley et al. (1969). The energy distribution from 1565 Armstrong to 1.25 micro is similar to that of a B5 III star and ...
  • JHK Spectroscopy of the Enigmatic Variable V445 Puppis 
    Ashok, N. M; Banerjee, D. P. K (Astronomical Society of India, 2003)
    Near-IR spectroscopic observations are reported for the enigmatic, nova-like, variable V445 Puppis. The near-IR spectra are hydrogen-deficient and unusually rich in CI lines. The spectra indicate that the object could be ...
  • Limited Seeing Measurements at Mount Abu Infrared Observatory 
    Ashok, N. M; Banerjee, D. P. K (Astronomical Society of India, 2002-12)
    Measurements of atmospheric seeing for the Mount Abu Infrared Observatory, Gurusikhar are presented. Observations made with a differential image motion monitor, between 6 December 1999 to 28 April 2000, give an ...
  • Modelling the synchrotron light curves in recurrent novae V745 Scorpii and RS Ophiuchi 
    Kantharia, N. G; Dutta, P; Roy, N; Anupama, G. C; Chitale, A; Ishwara-Chandra, C; Prabhu, T. P; Ashok, N. M; Banerjee, D. P. K (Astronomical Society of India, 2015-02)
    In this paper, we present the synchrotron light curve at 610 MHz from the recurrent nova V745 Sco following its outburst on 6 February 2014. The system has been detected and periodically monitored with the Giant Metrewave ...
  • Near infrared coronal line emission in nova Herculis 1991 
    Chandrasekhar, T; Ashok, N. M; Ragland, S (Astronomical Society of India, 1993)
    Near infrared coronal line emission at 1.98 +/- 0.02 micrometers due to (Si VI) detected in the spectrum of Nova Herculis 1991 as early as about 17 days after optical maximum is reported. The coronal line observations ...
  • Near infrared high angular resolution observations of stars and circumstellar regions by the technique of lunar occultations 
    Chandrasekhar, T; Ashok, N. M; Sam Ragland (Astronomical Society of India, 1993)
    A program of high angular resolution observations of stars and their circumstellar regions using the technique of lunar occultations has been initiated at the Physical Research Laboratory, Ahmedabad. A liquid nitrogen ...
  • Near Infrared Observations of Sakurai's Object during 1998-99 
    Kamath, U. S; Ashok, N. M (Springer, 2002-03)
    We present new near-infrared observations of Sakurai's Object obtained during 1998-99 when this final helium shell flash object was in the dust condensation phase. The infrared colours have reddened compared to earlier ...
  • Near infrared photometry of unassociated IRAS point sources in the zodiacal belt 
    Ashok, N. M; Chandrasekhar, T; Ragland, S; Watson, P. V (Astronomical Society of India, 1993)
    An observational program to generate a list of bright near infrared sources using IRAS Point Source Catalogue for further studies using lunar occultation technique has been initiated at Physical Research Laboratory, ...
  • Near-infrared and optical studies of the fast nova V4643 Sgr (Nova Sagittarii 2001) 
    Ashok, N. M; Banerjee, D. P. K; Varricatt, W. P; Kamath, U. S (Blackwell Publishing, 2006-05)
    V4643 Sagittarii or Nova Sagittarii 2001 was discovered in outburst at 7.7 mag on 2001 February 24. Here, we present near-infrared results of this fast classical nova obtained in the early decline phase in 2001 March ...
  • Near-infrared observations of nova Aquilae 1995 
    Kamath, U. S; Ashok, N. M; Chandrasekhar, T (Astronomical Society of India, 1996)
    JHK photometry of the slow, Fe-II type nova- Nova Aquilae 1995- obtained at the 1.2m Gurushikhar Infrared Telescope (GIRT) is presented here. Evidence for the presence of dust in the nova ejected based on these observations ...
  • Near-Infrared Spectra of Some Symbiotic Stars 
    Kamath, U. S; Ashok, N. M (Astronomical Society of the Pacific, 2003)
  • Near-infrared spectroscopy of nova Sagittarii 1998 
    Ashok, N. M; Chandrasekhar, T (Astronomical Society of India, 2000)
    Near-infrared spectra of Fe-II type nova, Nova Sagittarii 1998 obtained during the period 30 to 70 days after the discovery date are presented. The near infrared spectrum is dominated by emission lines of hydrogen and ...
  • Near-infrared spectroscopy of Nova Sagittarii 2001 (V4643 Sgr) 
    Ashok, N. M; Banerjee, D. P. K; Varricatt, W. P (Astronomical Society of India, 2002-09)
    Near-infrared spectra of the very fast ReiN-type nova, Nova Sagittarii 2001 (V464a Sgr) obtained in the early decline phase and the period 110 to 170 days after the discovery date are presented. The spectrum in the early ...

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