Abstract
During the past 15 years almost 190 natural sources of 22 GHz water maser emission have been found in the dusty circumstellar shells of late-type stars undergoing mass-loss. Numbered among these sources are ∼75% of the Mira variables within 400 pc of the Sun1, although only 34% of Miras in general are associated with OH masers2. Stars enshrouded by circumstellar matter are easily recognized today by the characteristic colour-range of their far infrared flux3. The accuracy of this discrimination has been well-tested during searches for OH masers4–6, which unlike water masers7 depend on the infrared for their pumping. Colour-selecting IRAS (Infrared Astronomy Satellite) sources provides a convenient means of pinpointing likely new water masers, an approach first tested by Engels et al.4. We report here on the initial results of a more extensive survey, during which we found 60 masers, 49 of them detections. Most are associated with 1,612-MHz masers, but 7 are sources without other known masers. Our results rule out the binary hypothesis2,8 as a plausible general explanation for the existence of the many sources having far infrared colours typical of OH/infrared stars, which show no sign of any 1,612-MHz emission. Our data support the idea that sources evolve in both their colours and their rate of mass-loss.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Bowers, P. F. & Hagen, W. Astrophys. J. 285, 637–647 (1984).
Herman, J. & Habing, H. J. Phys. Rep. 124, 255–314 (1985).
Lewis, B. M. in Late Stages of Stellar Evolution (eds Kwok, S. & Pottasch, S. R. ) 75–78 (Reidel, Dordrecht, 1987).
Engels, D., Habling, H. J., Olnon, F. M., Schmid-Burgk, J. & Walmsley, C. M. Astr. Astmphys. 140, L9–L12 (1984).
Lewis, B. M., Eder, J. & Terzian, Y. Nature 313, 200–202 (1985).
Eder, J., Lewis, B. M. & Terzian, Y. Astrophys. J. Suppl. (in the press).
Cooke, B. & Elitzur, M. Astrophys. J. 295, 175–182 (1985).
Lewis, B. M., Eder, J. & Terzian, Y. Astr. J. 94, 1025–1034 (1987).
Habing, H. J. in IAU Symp. 122: Circumstellar Matter (eds Appenzeller, I. & Jordan, C.) 197–213 (Reidel, Dordrecht, 1987).
IRAS Point Source Catalogue (US Government Printing Office, Washington DC, 1985).
Engels, D. Astr. Astrophys. Suppl. 36, 337–345 (1979).
Chapman, J. M. & Cohen, R. J. Mon. Not. R. astr. Soc. 220, 513–528 (1986).
Diamond, P. J. et al. Astr. Aslrophys. 174, 95–102 (1987).
Engels, D., Schmid-Burgk, J. & Walmsley, C. M. Astr. Astrophys. 167, 129–144 (1986).
Crocker, D. A. & Hagen, W. Astr. Astrophys. Suppl. 54, 405–416 (1983).
Dickinson, D. F. & Dinger, A. St. C. Astrophys. J. 254, 136–142 (1982).
Abt, H. A. Rev. Astr. Astrophys. 21, 343–372 (1983).
Rowan-Robinson, M., Lock, T. D., Walker, D. W. & Harris, S. Mon. Not. R. astr. Soc. 222, 273–286 (1986).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Lewis, B., Engels, D. Efficient detection of water masers. Nature 332, 49–51 (1988). https://doi.org/10.1038/332049a0
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1038/332049a0
- Springer Nature Limited