Variability of water masers in evolved stars on timescales of decades
Date Issued
2018
Author(s)
Abstract
For several decades (1987-2015) we have been carrying out observations of water masers in the circumstellar envelopes (CSE's) of Mira variables, Red Supergiants (RSG's) and Semi-Regular Variables (SRV's) with the Medicina 32-m and Effelsberg 100-m antennas. The single-dish monitoring observations provide evidence for strong H2O maser profile variations, which likely are connected to structural changes in the maser shells. Such variations include strong flares in intensity lasting several (tens of) months and systemic velocity gradients of maser components developing over years, as well as other secular variations which are superimposed on periodic variations following the stellar light variations.
When complemented with interferometric observations, it is possible to derive the 3-D distribution of the maser spots, and their lifetime, as we have done for RX Boo (Winnberg et al. 2008) and U Her (Winnberg et al. 2011; Brand et al. in prep.).
Coverage
Astrophysical Masers: Unlocking the Mysteries of the Universe
All editors
Tarchi, Andrea; Reid, Mark J.; Castangia, Paola
Volume
vol. 13, S336
Start page
393
Conferenece
Astrophysical Masers: Unlocking the Mysteries of the Universe
Conferenece place
Cagliari, Italy
Conferenece date
4-8 September, 2017
Issn Identifier
1743-9213
Ads BibCode
2018IAUS..336..393B
Rights
open.access
File(s)![Thumbnail Image]()
Loading...
Name
Brand-IAU336.pdf
Description
Pdf editoriale
Size
180.87 KB
Format
Adobe PDF
Checksum (MD5)
b88a782fadb9b755094ed91fa7d3e1fb