Found 4 talks width keyword novae
Abstract
Lithium is a key element which plays an important role in astronomy as well as everyday human life. Nevertheless it is probably the only element whose astronomical origin is still a mystery. A fraction of about 30% of what is measured today was made in the first 3 minutes of the Universe and about 10% is made by spallation reactions of cosmic rays with the atoms in the interstellar medium. However, as stars burn Li in their hot interiors and what makes the remaining ~60% is still unknown. The recent detections of 7Li and 7Be in the outburst of classical novae is a landmark in the solution of this long standing mystery. The discovery confirms a theoretical speculation made about 50 years ago but which was never supported by observations. Since then the presence of Be-7 has been confirmed to be ubiquitous in about a dozen classical novae and very recently also in the recurrent nova RS Oph that blew out in August 2021. However, the observed values show tension with theory being one order of magnitude greater than predictions. Detailed Li Galactic chemical evolution models assuming the "observed" yields show that indeed Novae could be the long sought source for the Galactic 7Li.
Abstract
MASTER-Kislovodsk auto-detection system discovered a faint transient in the Andromeda galaxy on January 13th 2015. It was originally identified as a classical nova and received designation M31N 2015-01a. Further observations showed discrepancies with the spectra and lightcurves typical for the classical novae. The transient was re-identified as a likely stellar merger (aka Luminous Red Nova (LRN)), similar to V838Mon. In this presentation I will deliver a short overview of our current understanding of this class of objects and a summary of the current state of the ongoing observing campaign of the M31 LRN. Recent results will be discussed with a particular emphasis on the contributions made possible by GTC and other observing facilities at Observatorio Roque de los Muchachos. At the final part of the presentation I will touch on follow up observations once M31 is available for observations again.
Abstract
The Astrophysics Research Institute (ARI) was established at LJMU in 1992. Today the Institute comprises around 70 staff and research students working on topics ranging from stellar evolution to cosmology. In this talk I will give an overview and some highlights of the work undertaken in recent years on Classical and Recurrent novae by the nova group of the ARI. This involves multi-frequency observations of both Galactic novae and those in Local Group galaxies and includes topics such as the exploration of their potential links to the progenitors of Type Ia supernovae. Along the way, I will briefly describe the work of the Liverpool Telescope on La Palma, one of whose primary science drivers is the efficient and effective observation of transient objects such as these, and look forward to our plans for the development of an even larger and faster-reacting robotic telescope at ORM - currently codenamed 'LT2".
Abstract
Spectroscopic observations of novae date back a century, and the fundamental nature of the outburst has been understood for 50 years. Yet, recent observations suggest possible major modifications to the standard nova paradigm. A high-resolution spectroscopic survey of novae has revealed short-lived heavy element absorption systems near maximum light consisting of Fe-peak and s-process elements. The absorbing gas is circumbinary and it must pre-exist the outburst. Its origin appears to be mass ejection from the secondary star, implying large episodic mass transfer events from the secondary that initiate the nova outburst. The spectroscopic evolution of novae is interpreted in terms of two distinct interacting gas systems in which the bright continuum is produced by the outburst ejecta but absorption and emission lines originate in gas ejected by the secondary star in a way that may explain dust formation and X-ray emission from novae.« Newer Older »
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