Optical photometry of SS 433: 200 nights of data 1979 1980
Abstract
We report the results of over 200 nights of photoelectric photometry of SS 433, over the period July 1979-October 1980. The data include 199 nightly points in unfiltered light (S-20); 166 points in V band; 26 points in a far-red band; and 46 points in a narrow (12 Å wide) interference-filter band centered on stationary Hα, at 6567 Å. We find: (1) Improved evidence for an underlying 164 d light variation, with peak-to-peak amplitudes 0. m50 in V and 0. m7 in λ6567; the object is brightest during maximum separation of the "moving" lines. (2) A binary-like variation with period 13. d074 ± 0. d020, with peak-to-peak amplitudes (as averaged coherently over the entire data sets ) of 0. m50 in V and 0. m60 in λ6567. (3) Additional irregular behavior, with occasional changes of more than 1 mag in 2-3 days. In the 13. d07 cycle, the variation is double-peaked with unequal minima: the deeper minimum occurs at times given by the ephemeris fJD 2444071.38 + 13.074 E, for V filter. The deeper minimum for λ6567 (stationary Hα) is shifted ahead — i.e. is delayed in time — by 0.2 cycle. The 13-day light curves are somewhat influenced by the 164 d process, as we show by a decomposition of the data into four segments of the 164 d cycle. The 13 d and 164 d light variations are discussed briefly in terms of a conventional close-binary model. Such a model fails, however, to account for several of the photometric, spectroscopic, and physical constraints, and quite different models must be looked at.
- Publication:
-
Vistas in Astronomy
- Pub Date:
- 1981
- DOI:
- 10.1016/0083-6656(81)90041-6
- Bibcode:
- 1981VA.....25...31K
- Keywords:
-
- Binary Stars;
- Light Curve;
- Night Sky;
- Radio Stars;
- Stellar Spectra;
- Stellar Spectrophotometry;
- Diurnal Variations;
- Emission Spectra;
- Line Spectra;
- Star Distribution;
- Stellar Models;
- Astronomy