Central Bureau for Astronomical Telegrams
IAUC 3268: N Cyg 1978
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Circular No. 3268
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
NOVA CYGNI 1978
P. J. Andrews and C. Lloyd, Royal Greenwich Observatory, telex:
"Spectrograms (dispersion 30 A/mm) covering the range 3700-7000 A
obtained with the 75-cm reflector show a very rich blue-shifted
absorption spectrum of type A with emission components redward of the
strongest lines of H, Fe II (multiplets 42, 49, 27) and O I. The
emission components increased in strength between Sept. 12.8 and
14.8 UT. Two absorption systems were measured at H-alpha with velocities
of -600 and -1300 km/s. Absorption features measured in the
Na D lines have zero velocity (interstellar) and -650 km/s."
An exposure of limiting magnitude B = 14 with the Greenwich 66-cm
refractor on Sept. 7.88 UT does not show the nova. E. D.
Clements has measured the following precise position from another
Greenwich plate: R.A. = 21h40m38s.09, Decl. = +43o48'10".6 (equinox 1950.0),
and Lloyd and R. W. Argyle confirm the Shao candidate (IAUC 3263)
for the probable prenova on the Palomar Sky Survey (B ~ 20; at the
limit of the red plate). D. di Cicco, Sky and Telescope, reports
that the nova is definitely absent on an exposure of limiting magnitude
~ 12 obtained by B. Mayer, PROBLICOM survey, on Sept. 8.34 UT.
The following Johnson-system magnitudes have been reported:
Sept. V B - V Observer Sept. V B - V Observer
12.05 6.0 +0.6 Lloyd 14.04 6.00 +0.46 Stelz
13.08 6.2 +0.5 Stelz 14.043 6.18 +0.50 Mallama
Lloyd and Argyle (Greenwich Observatory). Photographic photometry.
Stelz (Munich Observatory).
A. D. Mallama and D. R. Skillman (Goddard Space Flight Center). Apparent
fluctuations of 0.03 magnitude in course of several hours.
B. Jones and K. M. Merrill obtained the following combined
infrared magnitudes on Sept. 15.3 UT with bolometers at the University
of Minnesota's Mount Lemmon and O'Brien Observatories: R = 6.5;
I = 5.9; 1.2 um, 5.0; 1.6 um, 4.7; 2.2 um, 4.4; 3.6 um, 3.8; 4.9 um, 3.2;
8.6 um, 2.8. They add that careful monitoring for expected episodes
of buildup of infrared excess due to free-free emission, 5-um excess
emission and the onset of dust formation are needed.
Visual magnitude estimates: Sept. 15.13 UT, 6.8 (C. Hurless,
Lima, Ohio); 15.17, 6.8 (di Cicco); 15.27, 6.7 (D. W. E. Green,
Valparaiso, Indiana); 16.20, 7.0 (di Cicco); 16.42, 6.8 (D.
Wallentinsen, Albuquerque, New Mexico); 17.29, 7.1 (di Cicco).
1978 September 18 (3268) Brian G. Marsden
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