Search arXiv⌕ Search
Home/Archive/arXiv

arXiv · 0812.4096

Near Infrared Observations of the novae V2491 Cygni and V597 Puppis

Sachindra Naik·D. P. K. Banerjee·N. M. Ashok
View original source ↗Read source document ↗Export metadata ↓

Abstract

We present results obtained from near-infrared JHK spectroscopic observations of novae V2491 Cyg and V597 Pup in the early declining phases of their 2007 and 2008 outbursts respectively. In both objects, the spectra displayed emission lines of HI, OI, HeI and NI. In V597 Pup, the HeI lines were found to strengthen rapidly with time. Based on the observed spectral characteristics, both objects are classified as He/N novae. We have investigated the possibility of V2491 Cyg being a recurrent nova as has been suggested. By studying the temporal evolution of the line widths in V2491 Cyg it appears unlikely that the binary companion is a giant star with heavy wind as in recurrent novae of the RS Oph type. Significant deviations from that of recombination case B conditions are observed in the strengths of the HI lines. This indicates that the HI lines, in both novae, are optically thick during the span of our observations. The slope of the continuum spectra in both cases was found to have a λ^-(3-3.5) dependence which deviates from a Rayleigh-Jeans spectral distribution. Both novae were detected in the post-outburst super-soft X-ray phase; V2491 Cyg being very bright in X-rays has been the target of several observations. We discuss and correlate our infrared observations with the observed X-ray properties of these novae.

Explore related subjects

astro-ph

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Sachindra Naik, D. P. K. Banerjee, N. M. Ashok. 2008-12-22. Near Infrared Observations of the novae V2491 Cygni and V597 Puppis. https://doi.org/10.1111/j.1365-2966.2009.14421.x

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2025

A Cyclical Baryonic Big Bang Explains the Universe

Our universe has multiple examples of unexplained gravitational losses in black holes and neutron stars. The smallest black holes of about 4 solar masses means the maximum baryon density ρ\approx 10^{17} grams/cm^3. Any collapse of the universe will stop with a scale factor \approx 10^{13} cm. and radiation energy \approx 10 GeV. Due to higher squeezed core baryons, the outer part of the mass transferred energy to the core and became dark matter. After contraction reduced particle motion and gravitation, the core radiation energy propelled pieces of the shell into the universe. Each of these masses captured hot core gases according to its gravitational size, forming proto-galaxies. A cold shell and a hot core explain the Planck spectrum and large galaxy formation in the early universe. Thus the universe was never radiation dominant.The universe will remain cyclical as any increase in entropy of matter will be crushed back to neutrons during the contraction phase.

astro-ph↗
arXiv2024

A survey of debris trails from short-period comets

We observed 34 comets using the 24 micron camera on the Spitzer Space Telescope. Each image contains the nucleus and covers at least 10^6 km of each comet's orbit. Debris trails due to mm-sized or larger particles were found along the orbits of 27 comets; 4 comets had small-particle dust tails and a viewing geometry that made debris trails impossible to distinguish; and only 3 had no debris trail despite favorable observing conditions. There are now 30 Jupiter-family comets with known debris trails, of which 22 are reported in this paper for the first time. The detection rate is >80%, indicating that debris trails are a generic feature of short-period comets. By comparison to orbital calculations for particles of a range of sizes ejected over 2 yr prior to observation, we find that particles comprising 4 debris trails are typically mm-sized while the remainder of the debris trails require particles larger than this. The lower-limit masses of the debris trails are typically 10^11 g, and the median mass loss rate is 2 kg/s. The mass-loss rate in trail particles is comparable to that inferred from OH production rates and larger than that inferred from visible-light scattering in comae.

astro-ph↗
arXiv2024

Deformation procedure for scalar fields in cosmology

This work offers an extension of the deformation procedure introduced in field theory to the case of standard cosmology in the presence of real scalar field in flat space-time. The procedure is shown to work for many models, which give rise to several different cosmic scenarios, evolving under the presence of first-order differential equations which solve the corresponding equations of motion very appropriately.

astro-ph↗