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IAUC 5127: Prob. DWARF N IN For; MWC 560

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                                                  Circular No. 5127
Central Bureau for Astronomical Telegrams
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

     W. Liller, Vina del Mar, Chile, reports his discovery, with a
0.20-m Schmidt telescope + Problicom, of a very blue stellar object
in outburst, at R.A. = 3h24m49s, Decl. = -34 37'.0 (equinox 1950.0),
providing the following Tech pan film magnitudes:  Oct. 27.28 UT,
12.5; 28.31, 12.5; 29.32, 12.6.  M. Phillips, Cerro Tololo Interamerican
Observatory, reports the following CCD magnitudes obtained
by M. Hamuy and R. Lamontagne with the CTIO 0.9-m telescope on Oct.
29:  B = 12.79, V = 12.69.  Spectra (range 450-680 nm) obtained by
F. Baganoff and J. Maza with the CTIO 1.5-m and 4-m telescopes on
Oct. 29 show broad absorptions of H-alpha, H-beta, He I, and possibly
weak He II 469-nm; there is no evidence that these lines are
shifted, and there are no emission features.  An exposure of the
region on Oct. 23 (+/- 1 day) by M. Wischnjewsky, University of
Chile, shows nothing to B = 19, and nothing is present to the limit
of the ESO Sky Survey.

MWC 560
     R. M. Wagner and R. Bertram, Ohio State University; S.
Starrfield, Arizona State University; and S. Kenyon, Center for
Astrophysics, report:  "Optical spectra (ranges 440-560 and 594-700
nm; resolution 0.45 nm) were obtained of MWC 560 on Oct. 23.47 UT
with the Perkins 1.8-m telescope at the Lowell Observatory using the
Ohio State CCD spectrograph.  Features present in the spectra
include H-alpha, H-beta, Fe II (multiplets 40, 42, 46, and 74), Ca I
(18), and possibly He I 667.8-nm and Mn I 660.5-nm, all in emission.
In addition, the 443.0- and 628.4-nm interstellar absorption
features are present.  The H-alpha, H-beta, and Fe II (42) lines
exhibit deep P-Cyg profiles.  The center of the absorption components
is shifted -400 to -500 km/s and the blue edge extends to almost
-1900 km/s with respect to the nominal rest wavelengths.  The
equivalent width of H-alpha and H-beta absorption is about 0.9 nm with
FWHM about 550 km/s.  The optical spectrum of MWC 560 has changed
substantially since observations obtained in early Mar. (IAUC 4980,
4987, 4990) and now closely resembles that of some classical novae
early in their outburst, such as QV Vul (Nova Vul 1987).  Michalitsianos
et al. (IAUC 5108) have suggested a similar resemblance based
on ultraviolet spectra obtained on Sept. 26.  These observations
confirm that MWC 560 has ejected a cool, optically thick shell.  It
should now be monitored for the appearance of a nebular-phase spectrum
and for possible dust formation as occurred early in the
outburst of QV Vul."

1990 October 30                (5127)             Daniel W. E. Green

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