Central Bureau for Astronomical Telegrams
IAUC 3379: SS 433
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Read IAUC 3380
Circular No. 3379
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Postal Address: Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
TWX 710-320-6842 ASTROGRAM CAM Telephone 617-864-5758
SS 433
K. Horne and R. Gomer, California Institute of Technology,
report that results of high-speed photometry of SS 433 on June 4 with
the Mount Wilson 250-cm telescope and broad-band response of an S-20
photocathode show no evidence for a periodic flickering. They
find no periodic signals with a 90-percent confidence upper limit
of 0.0018 magnitude for periods in the range 5 to 0.2 s. This
reduces the upper limit reported on IAUC 3363 and extends the range
of periods over which the optical light from SS 433 shows no
periodic variations.
J. C. Kemp, Physics Department, University of Oregon, reports
linear polarization in the broad band 4500-7600 A on 11 nights
from June 20 to July 4 UT using the 81-cm telescope at Pine Mountain.
The mean for all nights was p = 3.06 +/- 0.60 percent at p.a.
3o.1 + 3o.0, roughly commensurate with a few unpublished data by
others. Night to night variability with some pattern was suspected,
especially in the p value, but could have been spurious, and monitoring
continues. Three 11th-magnitude field stars within 9' had
broad-band polarizations of ~ 0.5 percent at p.a. 50o-91o, but the
nearest brighter star (V = 13.7, B-V = 0.7), 55" northwest of SS
433, had p = 1.5 percent and p.a. 14o. The relative intrinsic and
interstellar contributions in the object's polarization remain an
open question. Suspicions of a non-interstellar part are raised by
the vanishingly-small polarization at 2.2 um noted by Thompson et al.
(1979 preprint submitted to Astrophys. J. Letters).
C. D. Impey, Department of Astronomy, University of Edinburgh,
communicates: "The following J, H, K and L' (= 3.8 um) observations
of SS 433 were obtained with the 380-cm infrared telescope on Mauna
Kea: 1979 May 25.58 UT, J = 9.57, H = 8.77, K = 8.17; 27.53, 9.00,
8.27, 7.72, L' = 6.61; 29.57, 8.79, 8.01, 7.47, 6.39; 30.53, 9.34,
8.78, 7.78, 6.58. The final night shows anomalous colors which are
not attributable to changes in the instrumental zero point; the
total photometric error is 0.05 magnitude. Variations greater than
0.5 magnitude are therefore observed at these wavelengths over a
24-hour period. It is not possible to establish variations over a
period of 1 month, since no zero points are given in the data of
Milone and Clark (IAUC 3354).
1979 July 20 (3379) Daniel W. E. Green
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