Central Bureau for Astronomical Telegrams
IAUC 5479: N Cyg 1992
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Circular No. 5479
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
NOVA CYGNI 1992
M. Kidger, Instituto de Astrofisica de Canarias, communicates the
following results from CVF spectra (range 1.4-2.4 microns, resolution
55 nm) obtained by J. Gallego, A. Alonso and himself on Mar. 4.28, 6.28
and 9.28 UT with the 1.5-m Carlos Sanchez Telescope of El Observatorio
del Teide, Tenerife. The spectra all show a very intense Pa-alpha
line at 1.86 microns (much more intense than in Nova Her 1991). The
integrated flux in Pa-alpha increased approximately 20 percent between
Mar. 4 and 9, although the continuum at 1.5 microns fell by nearly 50
percent between these dates. A prominent Br-gamma line is seen at
2.167 microns, the 9-4 transition is seen as a blue wing to Pa-alpha
at 1.82 microns, and the 10-4 and 11-4 transitions are seen at 1.74
and 1.68 microns. Possible very weak He I emission is seen at 2.06
microns, especially in the Mar. 9 spectrum. The Pa-alpha line is
partly resolved, indicating a high expansion velocity. The FWHM
corrected for instrumental resolution is 3900 km/s.
Kidger also reports the following photometry, obtained by the
same observers and R. Casas, R. Barrena and A. Darias: Mar. 5.257 UT,
V = 5.83 +/- 0.02, B-V = +0.34 +/- 0.04 (comparison star HR 7876);
6.255, V = 5.90 +/- 0.02, B-V = +0.37 +/- 0.02 (comparison star HR
7854); 10.261, J = 4.62 +/- 0.03, H = 4.73 +/- 0.02, K = 4.44 +/-
0.03; 11.274, J = 4.66 +/- 0.02, H = 4.80 +/- 0.02, K = 4.48 +/-
0.02. Visible photometry was with the 0.51-m Mons Telescope and
infrared photometry with the Sanchez Telescope.
P. Garnavich, Dominion Astrophysical Observatory; and T.
Kennelly, University of British Columbia, communicate: "Spectra of
Nova Cyg 1992 were obtained on Mar. 11.5, 12.5, 13.5 and 14.5 UT using
the DAO 1.2-m telescope and coude spectrograph providing a resolution
of 0.045 nm. The complex H-beta P-Cyg absorption system continued to
develop during the observation period. A flat-bottomed absorption
trough deepened and broadened, and by Mar. 14 it extended from -2300
to -2920 km/s. The maximum velocity is comparable to the highest
velocities observed by IUE (IAUC 5456) near maximum light. The flux
in the trough was 10 percent of the nearby continuum. An absorption
band with a minimum at -1580 km/s remained unchanged over the four
nights, but another near -2000 km/s strengthened and progressed blueward
at approximately -65 km/s per day. Emission components on top of the
broad H-beta and Fe II (516.90 nm) lines were also seen at -440, -220,
-80, +380 and +750 km/s."
1992 March 20 (5479) Brian G. Marsden
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