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Alert Notices

          THE AMERICAN ASSOCIATION OF VARIABLE STAR OBSERVERS
                25 Birch Street, Cambridge, MA 02138 USA
                       INTERNET:  aavso@aavso.org
                Tel. 617-354-0484       Fax 617-354-0665


                  AAVSO ALERT NOTICE 277 (July 13, 2000)


0526-70  NOVA LMC 2000 IN THE LARGE MAGELLANIC CLOUD

We have been informed by William Liller, Vina del Mar, Chile, and the Central
Bureau for Astronomical Telegrams (IAU Circular 7453) that Liller discovered a
nova in the Large Magellanic Cloud on photographic images taken July 12.4098
and 12.4129 UT, using unfiltered Kodak Technical Pan film and a 0.2-m Schmidt
camera.  Liller estimated the nova to be photovisual magnitude 11.2.  A photo
taken by him of this region on March 8, 1999, showed nothing to the film limit.

The nova was visually confirmed by Rod Stubbings, Drouin, Victoria, Australia,
who observed it at visual magnitude approximately 11.8 on July 13.469 UT.
(Stubbings used GSC 9166 673 for a comparison star; he commented that using
the nearby VW Hyi sequence yielded a magnitude of 12.2.)

Liller obtained a CCD (+ broadband V filter) image on July 12.98 UT that showed
the nova at magnitude 11.45; his image accompanies this Alert Notice.  Liller
measured the position of the nova on this image as:

     R.A. = 05h 25m 01.60s   Decl. = -70 degrees 14' 17.3" (equinox 2000.0)

Liller obtained a low-dispersion spectrum using a 0.2-m Schmidt telescope
with CCD on July 13.94 UT that shows the object to be a nova.  Liller also
commented that the nova could appear considerably fainter to visual observers
than his broadband-V magnitudes indicate because the spectrum is strongly
dominated by the red H-alpha line, to which the human eye is not very sensitive.

Also accompanying is an AAVSO 'e' scale Preliminary chart prepared by C.
Scovil.  Note that the sequence on this chart is very preliminary and is
subject to change.  The sequence comes from a variety of sources and so is
not homogeneous - if anyone can provide a uniform sequence, please contact
AAVSO Headquarters.   Please use this chart to observe 0526-70 N LMC 00 and
report your observations to AAVSO Headquarters, and be sure to indicate which
comparison stars you used to make your observations.

Congratulations to Bill on his latest discovery!


2138+43 SS CYGNI MULTIWAVELENGTH OBSERVATIONS RESCHEDULED

We extend most sincere thanks - on behalf of the astronomers and AAVSO
Headquarters - to all our observers who have been observing SS Cygni very
closely and sending their observations to us regularly.  Thanks to your
efforts and observations we were able to trigger the procedures for starting
the Target of Opportunity (ToO) observations with the three satellites -
Chandra x-ray satellite, RXTE, and EUVE (see AAVSO News Flash Nos. 613, 635,
and 642).

Unfortunately, due to problems with the high-energy grating on Chandra,
the ToO observations with that satellite could not be initiated when we
alerted them.  Since Chandra was the primary satellite for the ToO
observations of SS Cyg, the other satellite (RXTE and EUVE) observations were
also cancelled.

The astronomers at Lawrence Livermore National Laboratory, CA, and University
of Leicester, England, have informed us that they will have another opportunity
to observe SS Cyg with Chandra, RTXE, and EUVE satellites, hopefully during
its next outburst this summer, which we predict to occur around mid-August.

We have also been informed by astronomers at the Space Telescope Science
Institute that they plan to observe SS Cyg with the satellite FUSE
(Far-Ultraviolet Space Explorer) later this summer, and possibly at the same
time as the other three satellites, and they are also requesting our
assistance in notifying them of SS Cyg's behavior.

Immediate notification of SS Cyg's brightening so that the observations
using the three, and possibly four, satellites can be triggered will be
crucial, as it was for the July outburst. Please keep a very close eye on
SS Cyg and, once it has returned to minimum, inform us when you see it brighten
above 11.5.  As in this last observing campaign, it is your observations that
will enable the satellite observations to be triggered.


CHARTS AVAILABLE ON AAVSO WEB AND FTP SITES

Electronic copies of the image and chart of N LMC 00 mentioned in this Alert
Notice are available through our web site at the following address:

                         http://www.aavso.org

They may also be obtained directly from our FTP site:

             ftp.aavso.org (198.116.78.2), in /alerts/alert277

The answering machine at AAVSO Headquarters is on nights and weekends for
your convenience. Please call our charge-free number (888-802-STAR =
888-802-7827) to report your observations. We also encourage observers to
send observations by fax to 617-354-0665 or by e-mail through the Internet
to observations@aavso.org.

Many thanks for your valuable astronomical contributions and your efforts.

Good observing!

Janet A. Mattei
Director

Elizabeth O. Waagen
Senior Technical Assistant

Keywords:
AAVSO 49 Bay State Rd. Cambridge, MA 02138 aavso@aavso.org 617-354-0484