Related papers: Magnetic fields around late-type stars using water…
Through polarization observations, circumstellar masers are excellent probes of the magnetic field in the envelopes of late-type stars. Whereas observations of the polarization of the SiO masers close to the star and on the OH masers much…
We present the first circular polarization measurements of circumstellar water masers around a sample of late-type stars. These observations are used to obtain the magnetic field strength in the water maser region with both an LTE and…
We present circular polarization measurements of circumstellar H_2O masers. The circular polarization detected in the (6_{16}-5_{23}) rotational transition of the H_{2}O maser can be attributed to Zeeman splitting in the intermediate…
Through polarization observations water masers are excellent probes of magnetic fields in the maser region. Magnetic field strengths, such as those in the water masers regions of the envelopes of late-type stars and star-forming regions,…
We present circular polarization measurements of circumstellar water masers around 2 Mira variables and 4 supergaint stars. Both an LTE and non-LTE method are used to analyze the circular polarization and total intensity spectra and to…
We present the first circular polarization measurements of circumstellar H2O masers. Previously the magnetic field in circumstellar envelopes has been estimated using polarization observations of SiO and OH masers. SiO masers are probes of…
Both magnetic fields and photospheric/atmospheric dynamics can be involved in triggering the important mass loss observed in evolved cool stars. Previous works have revealed that these objects exhibit a magnetic field extending beyond their…
We present linear and circular polarization observations of the water masers in 4 distinct regions spread over 1x2 arcseconds around the HW2 high-mass young stellar object in the Cepheus A star-forming region. We find magnetic fields…
The linear polarization that is observed, together with likely changes in the orientation of the magnetic field along the line of sight and hence of the optical axes of the medium, can lead to the circular polarization that is observed in…
The majority of the observed planetary nebulae exhibit elliptical or bipolar structures. Theoretical modeling has indicated that magnetically collimated jets may be responsible for the formation of the non-spherical planetary nebulae. The…
We have identified and classified Zeeman pairs in the survey by Argon, Reid, & Menten of massive star-forming regions with 18 cm (2 Pi 3/2, J = 3/2) OH maser emission. We have found a total of more than 100 Zeeman pairs in more than 50…
Many observations of late-type M stars show large near-spherical circumstellar envelopes, yet planetary nebulae and supernova remnants are frequently axisymmetric. We present VLBI and MERLIN observations of masers around the red supergiant…
We aim to detect the magnetic field and infer its properties around four AGB stars using H$_2$O maser observations. The sample we observed consists of the following sources: the semi-regular variable RT Vir and the Mira variables AP Lyn, IK…
The goal of this work is to study magnetic fields of the cool, eclipsing binary star UV Piscium (UV Psc). This system contains two active late-type stars, UV Psc A (G5V) and B (K3V). To obtain a complete picture, the properties of both…
Context: Magnetic fields are thought to be one of the possible mechanisms responsible for shaping the generally spherical outflow of evolved stars into often aspherical planetary nebulae. However, direct measurements of magnetic fields…
MHD simulations show that the magnetic field can drive molecular outflows during the formation of massive protostars. The best probe to observationally measure both the morphology and the strength of this magnetic field at scales of 10-100…
A debated topic in star formation theory is the role of magnetic fields during the protostellar phase of high-mass stars. It is still unclear how magnetic fields influence the formation and dynamics of massive disks and outflows. Most…
Through polarization observations masers are unique probes of the magnetic field in a variety of different astronomical objects, with the different maser species tracing different physical conditions. In recent years maser polarization…
The integrated spectrum of OH emission from late-type stars is often circularly polarized, by as much as 50% in some cases. While the spectra are partially polarized, the individual maser components revealed by VLBI are much more so. Using…
Approximately 7% of massive stars host stable surface magnetic fields that are strong enough to alter stellar evolution through their effect on the stellar wind. It is therefore crucial to characterize the strength and structure of these…