Central Bureau for Astronomical Telegrams
IAUC 3365: SN IN NGC 4321; theta CrB; theta1 Tau
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Circular No. 3365
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
SUPERNOVA IN NGC 4321
R. Kirshner, University of Michigan, reports that spectrophotometry
at McGraw-Hill Observatory shows the presence of a line identified
with H-beta. This feature had developed by May 12 into a P-Cyg
profile with a violet-displaced minimum at a velocity of ~ -8850 +/-
200 km/s in the rest frame of NGC 4321. This velocity is much
higher than that reported by Panagia (IAUC 3353) based on ultraviolet
observations, but is similar to velocities in other type II supernovae.
As of May 23, the spectrum shows typical type II characteristics:
P-Cyg lines at H-gamma and H-beta, and a broad emission at H-alpha.
Other conspicuous type II features in the spectrum include distinct
minima at observed wavelengths of about 4460, 5075 and 5750 A.
Spectropolarimetry is highly desirable.
theta CORONAE BOREALIS
R. Poeckert, Dominion Astrophysical Observatory, communicates:
"Spectroscopic observations with the University of British Columbia
reticon at the 122-cm telescope showed a strong shell line, flanked
by weak emission, at H-alpha in the Be star theta CrB. The star was
observed on Mar. 28 and May 19, and the only apparent change in this
1.5-month interval is a weakening of the emission. A spectrogram
obtained on 1977 Apr. 12 shows no sign of a shell line at H-beta. The
full width of the shell line is 380 km/s; it has an approximately
triangular profile with central depth 0.65 of the continuum. The
weak emission has full width 755 km/s, v/r ~ 1, and a peak intensity
of 6 percent above the broad photospheric line."
theta1 TAURI
N. M. White, Lowell Observatory, writes: "theta1 Tauri, one of
four luminosity-class III Hyades cluster members, has been confirmed
to be double in six independent lunar occultation observations.
Observations from several sites indicate that the companion
is ~ 0".10 south of the primary and nearly 4.0 magnitudes fainter
at wavelengths between 4400 and 8500 A. The observations were
obtained in 1978 Sept. by W. Beavers and J. Eitter, Iowa State
University; R. Radick, University of Illinois; and myself; and in 1979
Mar. by J. Africano, Sacramento Peak Observatory, and R. Millis and
myself. Two-color observations at Lowell indicate the possibility
of a third faint component, but this has not been confirmed."
1979 June 4 (3365) Daniel W. E. Green
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