Central Bureau for Astronomical Telegrams
IAUC 3391: SS 433; gamma Cas
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Read IAUC 3392
Circular No. 3391
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
J. C. Kemp and M. Arbabi, Physics Department, University of
Oregon, communicate: "Photometry on 19 nights from July 15-August
5 UT was performed with the 81-cm telescope at Pine Mountain. Unfiltered
light was used (S-20 response, 3700-8000 A) to suppress
effects from the moving emission lines. Three comparison stars of
different colors were used. Some measures were also made in B and
V bands. We find: (1) The main feature was 2 transitions of amplitude
(0.42 and 0.25 magnitudes), with deep minima on July 16.6 and
29.3, and maxima on July 20.7 and August 2.3. Decline from the
first maximum was much slower than the rise. A period of 12d.5 +/-
0d.6 is conjectured. However, the amplitudes of the two strong features
were different. The object was slightly redder in the deep
minima. (2) Low amplitude modulation (0.05 magnitude) of period
3d may also be present. (3) On time scales 3m to 4h, no variation
exceeding 0.15 magnitude was seen. The 12.5-day period seems to
agree with the radial velocity period of 13d found by Crampton,
Colley and Hutchings (cf. IAUC 3388)."
A. Klemola and E. Harlan, Lick Observatory, report the following
position for equinox 1950.0 and mean epoch 1977.52 based on
three plates with the 51-cm astrograph: R.A. = 19h09m21s.31 +/- 0s.02
(m.e.), Decl. = +4o53'54s.2 +/- 0".1 (m.e.).
R. Harrington, U.S. Naval Observatory, also reports a precise
position, at epoch 1979.50 with the 155-cm astrometric reflector at
the Flagstaff station: R.A. = 19h09m21s.28, Decl. = +4o53'54".3. The
position is essentially identical to the 1951-epoch optical position
quoted by Seaquist et al. (1979, Astron. J. 84, 1037), confirming
that this object has no significant proper motion. The 1" difference
in declination between the radio and optical positions is probably
significant.
gamma CASSIOPEIAE
G. Hammerschlag-Hensberge, Astronomical Institute, University
of Amsterdam, telexes: "A recent ultraviolet IUE spectrum of gamma Cas
taken on Mar. 15 shows strong additional shell lines for the resonance
doublets of C IV 1550 A and Si IV 1400 A with a terminal velocity
near 1200 km/s. These shell lines were not visible on IUE spectra
taken in 1978 April-May. Optical observers are urged to look
for the presence of shell activity in the visible spectral region."
1979 August 13 (3391) Daniel W. E. Green
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