Detecting weak magnetic fields in the central stars of planetary nebulae
Steffen, M.; Hubrig, S.; Todt, H.; Schöller, M.; Sandin, C.;Hamann, W.-R.; Schönberner, D.
Abstract:
We have carried out low-resolution spectropolarimetric observations with
FORS 2, installed on the VLT, ESO, of a representative sample of 12
bright central stars of Planetary Nebulae (PNe) with different
morphology. Two of the sample are hydrogen-deficient (Wolf-Rayet type)
stars. Our measurements rule out the existence of strong global magnetic
fields of the order of kG in any of the PN central stars of our sample.
Even so, our data may indicate the presence of weak mean longitudinal
magnetic fields of a few hundred Gauss in the central stars of two
elliptical nebulae, IC 418 and NGC 2392, and a very weak magnetic field
of about 100 G in the Wolf-Rayet type central star Hen 2-113. However,
the significance of these marginal detections depends on the method
adopted for estimating the uncertainties in the magnetic-field
measurements.