Central Bureau for Astronomical Telegrams
IAUC 3258: H-alpha-EMISSI0N OBJECT SS 433; V1500 Cyg; IC 4997; HS Sge
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Read IAUC 3259
Circular No. 3258
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
H-alpha-EMISSI0N OBJECT SS 433
P. A. Feldman, Herzberg Institute of Astrophysics; C. R.
Purton, T. Stiff and S. Kwok, York University, write: "We observed
the radio source associated with the stellar object Stephenson-Sanduleak
No. 433 (cf. IAUC 3256) using the National Radio Astronomy
Observatory four-element interferometer on three occasions during
June 26-30. The flux density was variable, ranging from 530 to
675 mJy at 2.7 GHz and from 270 to 410 mJy at 8.1 GHz. The radio
spectrum was nonthermal with a 2.7-8.1-GHz spectral index of ~ -0.6
(cf. IAUC 3256), except on June 26.38 UT when it flattened to ~
-0.45 during a flaring episode in which the 8.1-GHZ flux density
increased by ~ 30 percent in less than 8 hours."
V1500 CYGNI
Corrigendum. The epoch for the deeper of the two minima (cf.
IAUC 3257) should read 1978 Aug. 1.48671 UT, not Aug. 1.55661 UT.
IC 4997
A. T. Purgathofer, Vienna University Observatory, writes: "On
IAUC 3118 Feibelman reported that in the variable planetary nebula
IC 4997 the [O III] 4363-A:H-gamma intensity ratio had changed from its
monotonically decreasing trend and reached a value somewhat greater
than unity in 1977 Aug. Calibrated spectrograms at a dispersion of
26 A/mm obtained with the Vienna Observatory's 150-cm telescope
show that the intensity ratio had returned to about 0.80 on 1978
Aug. 4.98 and 6.01 UT. This is noticeably different from the
result obtained only a year ago by McCracken, Brown and Hobbs. It
appears that in this nebula the [O III]/H-gamma ratio is subject to
variations of more than 20 percent on a timescale of a year or less.
It seems worthwhile to monitor IC 4997 more frequently. Further
observations are planned at our Observatory."
HS SAGITTAE
Further visual magnitude estimates: June 9.97 UT, 12.9 (G. M.
Hurst, Northampton, England); 29.19, 12.5 (S. O'Meara, Harvard
College Observatory); 13.22, 13.1 (O'Meara).
1978 August 31 (3258) Brian G. Marsden
Read IAUC 3259
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