Discovery of Multiple Shells Around the Planetary Nebula IC 418
Abstract
We have analysed optical, near-, and mid-IR images of the bright planetary nebula (PN) IC 418. These images probe unambiguously for the first time a number of low surface brightness structures and shells around the bright main nebula, including radial filaments or rays, a system of three concentric rings, and two detached haloes with sizes ~ 150" and 220"\times250", respectively. The main nebula is slightly off-centered with respect to the elliptical outer halo. The time-lapse between the two haloes is 10,000-50,000 yr, whereas the time-lapse between the three concentric rings is ~ 630 yr. We emphasize the advantages of near- and mid-IR imaging for the detection of faint structures and shells around optically bright nebulae.
Cite
@article{arxiv.1204.5816,
title = {Discovery of Multiple Shells Around the Planetary Nebula IC 418},
author = {Gerardo Ramos-Larios and Roberto Vazquez and Martin A. Guerrero and Lorenzo Olguin and R. A. Marquez-Lugo and Hector Bravo-Alfaro},
journal= {arXiv preprint arXiv:1204.5816},
year = {2015}
}
Comments
9 pages, 5 figures, accepted for publication in MNRAS