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arXiv · 1210.5884

A three-dimensional view of the remnant of Nova Persei 1901 (GK Per)

T. Liimets·R. L. M. Corradi·M. Santander-García·E. Villaver·P. Rodríguez-Gil·K. Verro·I. Kolka
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Abstract

We present a kinematical study of the optical ejecta of GK Per. It is based on proper motions measurements of 282 knots from ~20 images spanning 25 years. Doppler-shifts are also computed for 217 knots. The combination of proper motions and radial velocities allows a unique 3-D view of the ejecta to be obtained. The main results are: (1) the outflow is a thick shell in which knots expand with a significant range of velocities, mostly between 600 and 1000 km/s; (2) kinematical ages indicate that knots have suffered only a modest deceleration since their ejection a century ago; (3) no evidence for anisotropy in the expansion rate is found; (4) velocity vectors are generally aligned along the radial direction but a symmetric pattern of non-radial velocities is also observed at specific directions; (5) the total Halpha+[NII] flux has been linearly decreasing at a rate of 2.6 % per year in the last decade. The Eastern nebular side is fading at a slower rate than the Western one. Some of the knots displayed a rapid change of brightness during the 2004-2011 period. Over a longer timescale, a progressive circularization and homogenization of the nebula is taking place; (6) a kinematic distance of 400+-30 pc is determined. These results raise some problems to the previous interpretations of the evolution of GK Per. In particular, the idea of a strong interaction of the outflow with the surrounding medium in the Southwest quadrant is not supported by our data.

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T. Liimets, R. L. M. Corradi, M. Santander-García, E. Villaver, P. Rodríguez-Gil, K. Verro, I. Kolka. 2012-10-22. A three-dimensional view of the remnant of Nova Persei 1901 (GK Per). https://doi.org/10.1088/0004-637x/761/1/34

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