Nagarhalli M. Ashok

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Optical and near-infrared spectroscopic observations of the fast nova V1494 Aquilae 1999 # 2 covering various phases – early decline, transition and nebular – during the first eighteen months of its post-outburst evolution are presented in this paper. During this period, the nova evolved in the PfeP o fe Co spectral sequence. The transition from an(More)
V838 Monocerotis had an intriguing, nova-like outburst in 2002 January that has subsequently led to several studies of the object. It is now recognized that the outburst of V838 Mon and its evolution are different from those of a classical nova or other classes of well-known eruptive variables. V838 Mon, along with two other objects that have analogous(More)
The wavelength-dependence of the extinction of Type Ia SN 2014J in the nearby galaxy M82 has been measured using UV to near-IR photometry obtained with the Hubble Space Telescope, the Nordic Optical Telescope, and the Mount Abu Infrared Telescope. This is the first time that the reddening of a SN Ia is characterized over the full wavelength range of(More)
Aims. V838 Monocerotis erupted in 2002, brightened in a series of outbursts, and eventually developed a spectacular light echo. A very red star emerged a few months after the outburst. The whole event has been interpreted as the result of a merger. Methods. We obtained near-IR and mid-IR interferometric observations of V838Mon with the AMBER and MIDI(More)
We present optical observations of the enigmatic nova-like variable V4332 Sgr. The importance of this object should not be understated since it is considered to be the possible prototype of a new class of eruptive variables. These objects have been the subject of considerable studies at present primarily because of the spectacular eruption of V838 Mon(More)
We present optical and near infrared (NIR) observations of the nearby Type Ia SN 2014J. Seventeen optical and 23 NIR spectra were obtained from 10 days before (−10d) to 10 days after (+10d) the time of maximum B-band brightness. The relative strengths of absorption features and their patterns of development can be compared at one day intervals throughout(More)
We have searched for the important radioactive isotope Al in the nova-like source V4332 Sgr. Recent results from gamma ray astronomy show that there is pervasive emission of the 1.809 MeV gamma ray photon, arising from the decay of Al to Mg, from all over the galactic plane. Though the sites from where this emission originates are not clearly established,(More)