Astronomische Nachrichten, Volume 345, Issue 4, May 2024.Abstract The magnetic field in the O9.7 V star HD 54879 has been monitored for almost a decade. Spectropolarimetric observations reveal a rather strong mean longitudinal magnetic field that varies with a period of about 7.41 years. Observations in the Hα$$ \alpha $$ line show a variation with the same period, while the Hβ$$ \beta $$ line shows only ...
Manfred Küker +4 more
wiley +1 more source
SiO in C-rich circumstellar envelopes of AGB stars: effects of non-LTE chemistry and grain adsorption [PDF]
, 2006 Aims. New SiO multi-transition millimetre line observations of a sample of carbon stars, including J = 8 → 7 observations with the APEX telescope, are used to probe the role of non-equilibrium chemistry and the influence of grains in circumstellar ...
F. Schoeier, H. Olofsson, A. Lundgren
semanticscholar +1 more source
A deep search for C2H in the oxygen-rich post-AGB star OH 231.8+4.2
Frontiers in Astronomy and Space SciencesIn carbon-rich environment, C2H emission is seen to be associated with HC3N, but whether it can trace the HC3N molecule in oxygen-rich environment is unknown.
Jianchao Yang +5 more
doaj +1 more source
Cold CO gas in the envelopes of FU Orionis-type young eruptive stars
, 2017 FUors are young stellar objects experiencing large optical outbursts due to highly enhanced accretion from the circumstellar disk onto the star. FUors are often surrounded by massive envelopes, which play a significant role in the outburst mechanism ...
Csengeri, T. +5 more
core +1 more source
Do Water Fountain Jets Really Indicate the Onset of the Morphological Metamorphosis of Circumstellar Envelopes? [PDF]
, 2016 The small-scale bipolar jets having short dynamical ages from "water fountain (WF)" sources are regarded as an indication of the onset of circumstellar envelope morphological metamorphosis of intermediate-mass stars.
Hsia, Chih-Hao +3 more
core +2 more sources
Observations of Molecular CN toward S-type Asymptotic Giant Branch Stars
The Astronomical JournalS-type asymptotic giant branch (AGB) stars are defined by their carbon-to-oxygen (C/O) ratio approaching unity. However, observations of circumstellar molecules in these stars are limited and challenging.
Yanan Feng +11 more
doaj +1 more source
The unique chemistry in the envelopes of massive stars
Frontiers in Astronomy and Space SciencesThe envelopes of evolved massive stars (M ∼9–40 M⊙) on the Red Supergiant (RSG) Branch offer a unique situation to examine extreme circumstellar chemistry.
Lucy M. Ziurys
doaj +1 more source
The alignment of the polarization of HAe/Be stars with the interstellar magnetic field
, 2009 We present a study of the correlation between the direction of the symmetry axis of the circumstellar material around intermediate mass young stellar objects and that of the interstellar magnetic field.
A. Mário Magalhães +16 more
core +1 more source
Unexpectedly large mass loss during the thermal pulse cycle of the red giant R Sculptoris! [PDF]
, 2012 The asymptotic giant branch star R Sculptoris is surrounded by a detached shell of dust and gas. The shell originates from a thermal pulse during which the star undergoes a brief period of increased mass loss. It has hitherto been impossible to constrain
de Gregorio-Monsalvo, I. +12 more
core +2 more sources
Very Large Array Observations of H I in the Circumstellar Envelopes of Asymptotic Giant Branch Stars [PDF]
, 2007 We have used the Very Large Array to search for neutral atomic hydrogen (H I) in the circumstellar envelopes of five asymptotic giant branch stars. We have detected H I 21 cm emission coincident in both position and velocity with the S-type semiregular ...
L. Matthews, M. Reid
semanticscholar +1 more source