Non-detection of magnetic fields in the central stars of the planetary nebulae NGC 1360 and LSS 1362

TL;DR

This study used spectropolarimetric observations to search for magnetic fields in the central stars of two planetary nebulae but found no evidence of magnetic fields within the measurement errors, challenging previous claims.

Contribution

The paper provides the first null detection of magnetic fields in these stars using high-precision spectropolarimetry, contradicting earlier reports of magnetic field presence.

Findings

No magnetic fields detected within errors (<600 G)

Magnetic fields, if present, are weaker or more complex than previously thought

Supports further studies on magnetic field strength and morphology in PNe central stars

Abstract

The presence of magnetic fields is an attractive hypothesis for shaping PNe. We report on observations of the central star of the two Planetary Nebulae NGC1360 and LSS1326. We performed spectroscopy on circularly polarized light with the FOcal Reducer and low dispersion Spectrograph at the Very Large Telescope of the European Southern Observatory. Contrary to previous reports (Jordan et al. 2005, A&A, 432, 273), we find that the effective magnetic field, that is the average over the visible stellar disk of longitudinal components of the magnetic fields, is null within errors for both stars. We conclude that a direct evidence of magnetic fields on the central stars of PNe is still missing --- either the magnetic field is much weaker (< 600 G) than previously reported, or more complex (thus leading to cancellations), or both. Certainly, indirect evidences (e.g., MASER emission) fully justify further efforts to study the strength and morphology of such magnetic fields.