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 arcsec and ?, respectively. The main nebula is slightly off-centred 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.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- July 2012
- DOI:
- 10.1111/j.1365-2966.2012.21165.x
- arXiv:
- arXiv:1204.5816
- Bibcode:
- 2012MNRAS.423.3753R
- Keywords:
-
- ISM: jets and outflows;
- ISM: lines and bands;
- planetary nebulae: individual: IC 418;
- infrared: ISM;
- Astrophysics - Astrophysics of Galaxies;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- 9 pages, 5 figures, accepted for publication in MNRAS