The infrared variability and nature of symbiotic stars- III. R Aquarii.
Abstract
Infrared (JHKL) photometry of R Aqr for the period 1975-1981 is analyzed, together with relevant visual observations. It is shown that a simple model of partial obscuration by an opaque dust cloud can account for the decrease in brightness in 1975-1978. The percentage obscuration is greater at J (1.2 microns) than at V because at the latter wavelength the effective diameter of the star is greater. At L (3.5 microns) there is a significant contribution from a source with a color temperature of approximately 1000 K (presumably dust) that does not undergo obscuration. Extensive JHKL observations for the years 1972-1982 are then tabulated. It is noted that a Mira variable of period 590 days which has a distance of 3.0 kpc is present in the system. The mean J brightness of the system is found to be constant from 1975 to 1979 but then to decrease, as does the V brightness. Infrared variability and spectra are then presented to show that the symbiotic systems (He 2-106, He 2-38, He 2-34) contain Mira variable components. The first two also exhibit a longer term infrared variability.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- April 1983
- DOI:
- Bibcode:
- 1983MNRAS.203..351W
- Keywords:
-
- Astronomical Photometry;
- Binary Stars;
- Infrared Astronomy;
- Stellar Spectrophotometry;
- Variable Stars;
- Dust;
- Emission Spectra;
- Infrared Spectra;
- Light Curve;
- Line Spectra;
- Mira Variables;
- Periodic Variations;
- Tables (Data);
- Astronomy