Central Bureau for Astronomical Telegrams
IAUC 4844: V745 Sco; 1989o; R CrB
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Circular No. 4844
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Postal Address: Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
Telephone 617-495-7244/7440/7444 (for emergency use only)
TWX 710-320-6842 ASTROGRAM CAM EASYLINK 62794505
MARSDEN or GREEN@CFA.BITNET MARSDEN or GREEN@CFAPS2.SPAN
V745 SCORPII
H. W. Duerbeck, H. E. Schwarz, and T. Augusteijn, European
Southern Observatory, report: "The spectral evolution of V745
Sco was monitored in 1989 August, using the ESO 3.5-m New
Technology Telescope and 1.5-m telescope (range 370-820
nm, resolving power 1500). In the rich emission line spectrum,
lines of forbidden Fe VII, Fe X, and Fe XI have been seen since
Aug. 4; they reached maximum strength in mid-August and have now
faded considerably. The 683.0-nm symbiotic feature was always present.
In the red region, TiO bands of an M6-6.5 III star have emerged.
V745 Sco shares many features with RS Oph; its spectral
development is, however, four times as fast."
PERIODIC COMET BRORSEN-METCALF (1989o)
G. Cremonese and M. Lazzarin, Asiago Observatory, write:
"We observed P/Brorsen-Metcalf on Aug. 18 with the Asiago 1.82-m
telescope (+ Boller and Chivens spectrograph + CCD). The spectra
(range 370-660 nm, resolution 0.2 nm) show strong emission
features, including CN (388.0 nm), C3 (405.0 nm), C2 (473.7, 516.5,
563.5 nm), NH2 (610.7 nm), O I (630.0 nm), and weaker features
such as CN (421.6 nm) and CH (432.2 nm). We find a very weak
emission due to sodium after having applied a sky correction.
HCO emission is also seen at 483.8, 519.6, and 613.6 nm, which
was first identified by C. Cosmovici and S. Ortolani in comet
IRAS-Araki-Alcock 1983 VII; we encourage other observers to
look for HCO emission."
R CORONAE BOREALIS
K. Krisciunas, Joint Astronomy Centre, Hilo, reports the
following photometry (+/- 0.01 mag) obtained at Mauna Kea
using HD 141352 (V = 7.476, B-V = +0.439) as the comparison
star: June 10.42 UT, V = 6.09, B-V = +0.55; July 3.33, 6.26,
+0.59; Aug. 2.36, 6.41, +0.72; Aug. 27.27, 8.07, +0.74.
Visual magnitude estimates (cf. IAUC 4834): Aug. 13.50 UT,
7.0 (M. Iida, Nagano, Japan); 16.2, 7.2 (M. Kidger, La Palma,
Canary Islands); 19.84, 7.5 (M. Verdenet, Bourbon-Lancy, France);
22.94, 7.5 (J. D. Shanklin, Cambridge, England); 24.15, 7.8 (P.
Collins, Scottsdale, AZ); 26.1, 8.1 (J. E. Bortle, Stormville, NY);
28.21, 8.0 (C. Spratt, Victoria, BC); 30.84, 8.1 (P. Schmeer,
Bischmisheim, W. Germany).
1989 August 31 (4844) Daniel W. E. Green
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