130 research outputs found

    The peculiar ejecta of the nova V1425 Aquilae

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    Many important details of the mechanisms underlying the ejection of material during a (classical) nova eruption are still not understood. Here we present optical spectroscopy and narrow-band images of the nova V1425 Aql, 23 years after the nova eruption. We find that the ejecta consist of two significantly different components. The first resembles what is commonly seen in novae, that is, a symmetric distribution centred on the position of the underlying cataclysmic binary and presenting both allowed (hydrogen and helium) and forbidden ([OIII] and [NII]) transitions. The second one, on the other hand, consists of material travelling at an approximately three times higher velocity that is not visible in the allowed transitions, presents a significantly different [NII] - [OIII] ratio, and is located at approximately 2.3 arcsec to the southwest of the position of the binary. Comparing the velocities and spatial extensions of the two ejecta, we find that both originated in the same nova eruption. We explore possible extrinsic and intrinsic mechanisms for the asymmetry of the high-velocity material in the form of asymmetrically distributed interstellar material and magnetic accretion, respectively, but find the available data to be inconclusive. From the expansion parallax, we derive a distance for the nova of 3.3(3) kpc.Comment: 13 pages, 9 figures. Version updated for language editin

    Life after eruption - I. Spectroscopic observations of ten nova candidates

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    We have started a project to investigate the connection of post-novae with the population of cataclysmic variables. Our first steps in this concern improving the sample of known post-novae and their properties. Here we present the recovery and/or confirmation of the old novae MT Cen, V812 Cen, V655 CrA, IL Nor, V2109 Oph, V909 Sgr, V2572 Sgr, and V728 Sco. Principal photometric and spectroscopic properties of these systems are discussed. We find that V909 Sgr is a probable magnetic CV, and that V728 Sco is a high-inclination system. We furthermore suggest that the two candidate novae V734 Sco and V1310 Sgr have been misclassified and instead are Mira variables.Comment: 11 pages, 7 figures (some of them in lower resolution), to be published in MNRA

    The emission distribution of RR Pictoris

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    We present time-resolved optical spectroscopy of the old nova RR Pic. Two emission lines (Halpha and He I) are present in the observed part of the spectrum and both show strong variability. Halpha has been used for Doppler tomography in order to map the emission distribution in this system for the first time. The resulting map shows the emission from the disc as well as two additional emission sources on the leading and trailing side of the disc. Furthermore we find evidence for the presence of either a disc-overflow or an asymmetric outflow from the binary with velocities up to +- 1200km/s. The origin of the outflow would be the emission source on the leading side of the accretion disc.Comment: Latex, 7 pages, 10 figure
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