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Alert Notice 211: AAVSO on World Wide Web AND 1958+56 V1028 Cygni in outburst AND Brightening of 1601+67 AG Draconis AND 0409-71 VW Hydri observed with EUVE AND Reminders - GK Persei and T Pyxidis

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 211 (August 1, 1995)

AAVSO ON WORLD WIDE WEB

We are proud to announce that the AAVSO now has a home page available on the World
Wide Web (WWW). The address of our home page on the WWW is:

    http://www.aavso.org

Point your browser at this address for information on the AAVSO, variable stars, Alert
Notices and other Publications, sample light curves and many more. We will be updating
our web page periodically, and including finder charts and new light curves. We invite you
to visit the AAVSO home page frequently. Soon, for each light curve we put on our web
page, we will be listing the names of the contributing observers, so visit our home page and
see if you are one of those observers! For best results, we suggest that you use Netscape
1.1 to view the page. We welcome comments, suggestions, input, etc. Please send mail to
webmaster@aavso.org.

1958+56 V1028 CYGNI IN OUTBURST

We have been informed by our observers T. Burrows, Novato, CA, and D. York, Abiquiu,
NM, that they have independently observed the outburst of V1028 Cyg. We were also
informed via vsnet that J. Pietz, Erftstadts, Germany, independently observed this outburst.
Below are recent observations of V1028 Cyg:

Ju125.010 UT, < 14.0, E. Broens, Mol, Belgium; 25.994, < 13.9, G. Poyner, Birmingham,
England; 26.2521, < 14.0, T. Burrows, Novato, CA; 27.1563, < 16.0, D. York, Abiquiu, NM;
27.2542, < 14.0, Burrows; 27.2549, < 14.0, Burrows; 28.1868, 13.5, York; 28.2347, 13.5,
York; 28.2625, 13.7, Burrows; 28.967, 12.7, J. Pietz, Erftstadts, Germany; 29.1486, 12.7,
York; 29.1667, 12.7, York; 29.2174, 12.7, York; 29.911, 12.9, L. Szentaska; Budapest,
Hungary; 29.913, 13.0, Vanmunster; 30.2104, 13.3, J. Griese, Stamford, CT; 30.216, 13.1, J.
McKenna, Upper Montclair, NJ; 30.2542, 13.0, R. Stewart, Fairlawn, NJ; 30.2764, 13.0,
Burrows; 30.87, 12.9, Szentasko; 30.914, 12.7, Broens; 31.1319, 12.9, Stewart; 31.1875, 13.0,
McKenna; 31.2549, 13.0, Burrows; 31.3368,13.3, C. Scovil, Stamford, CT; Aug 1.08,13.5, G.
Dyck, Assonet, MA; 1.1889, 12.8, McKenna; 1.1458, 13.0, York; 1.1944, 12.9, York; 1.2111,
13.4, Griese; 1.250, 13.0, Burrows.

V1028 Cyg has been closely monitored by the AAVSO since 1981. Although it is classified
as an SS Cyg-type dwarf nova in the fourth edition of the General Catalogue of Variable
Stars
, and also in the Catalogue and Atlas of Cataclysmic Variables by Downes and Shara
(Publ. Astron. Soc. Pacific, 105, 127; 1993), the observations in the AAVSO International
Database suggest that it may be an SU UMa-type dwarf nova. It has had several short and
faint outbursts that lasted from one to four days and reached maximum magnitude between
13.5 and 14.4. It has also had one long outburst that was well-observed, in September 1992
- it began on September 5, reached maximum magnitude of 12.8 on the 6th, and was
brighter than 14.2 until the September 16. This outburst was the last confirmed one
observed of this dwarf nova until the present one, and it may have been a superoutburst.

The fact that this current outburst is bright suggests that it may also be a superoutburst. In
fact, Dr. T. Kato and the Ouda Team of astronomers in Japan who have been observing
V1028 Cyg since 29 July reported via vsnet that the outburst light curve initially showed
"very low amplitude (0.04 - 0.03 magnitude, alternately) double wave". Their CCD
photometry on July 30th indicated that 'true' superhumps with single-peak hump structure
had developed. Their CCD photometry on July 31 showed typical superhumps with 0.29
magnitude of amplitude and 0.063 day of period. Thus, these observations confirm the
suggestion we have made, studying the AAVSO light curves, that V1028 Cyg is an SU
UMa-type dwarf nova.

Accompanying are "d" and "e" scale AAVSO preliminary charts for V1028 Cyg prepared by
C. Scovil, using the visual sequence from Wayne Lowder that was on the earlier AAVSO
V1028 Cyg chart, for consistency, and a CCD(V) sequence from Kato et al. (Kyoto
University) to extend the sequence. We recommend that observers use these charts in
making observations, and indicate the comparison stars used when reporting the
observations.

We strongly recommend that visual and, particularly, CCD observers, observe the
superhumps by monitoring this star every three minutes for as long as possible during the
night, throughout the this superoutburst. Continue your nightly observations even after the
outburst to detect possible brightening. Please record the exact time of the your
observations to four decimals of the day.

Our sincere congratulations to Tom Burrows, Dave York, and Joachim Pietz for "catching"
this outburst so early and to Dr. Kato and the Ouda Team for their excellent CCD
photometry of this superoutburst.

BRIGHTENING OF 1601+67 AG DRACONIS

The symbiotic star AG Dra has started to brighten slowly, as indicated by the
accompanying light curve. The list of observers contributing to this light curve is given on
the light curve page. It may be seen by this light curve that the last outburst of AG Dra
started at the end of May 1994, and reached maximum at average magnitude 8.3 by the end
of July 1994.

Accompanying are "b" and "d" scale AAVSO charts of AG Dra. Please monitor AG Dra
closely, and report your observations, specifically stating the source and the date of the
chart, and the comparison stars you have used.

0409-71 VW HYDRI OBSERVED WITH EUVE

Excellent EUV data were obtained of the recent outburst of VW Hyi with the EUVE
satellite! On July 7, W. Liller, D. Overbeek, and J. Hers telephoned to inform us that the
predicted outburst had started. The EUVE Deputy Project Scientist was able to start the
observations with the EUVE 3 hours and 43 minutes after our notification that VW Hyi
had gone into outburst! The satellite observed VW Hyi continuously until July 18, and
obtained fantastic and unprecedented data of the outburst and of the quiescence. The
EUVE data indicate clearly that the outburst in EUV started about 0.5 day after the
optical outburst. In addition to EUVE, the satellite Voyager observed VW Hyi
simultaneously.

Thus, during this short outburst that lasted only three days, this star was observed from 80
to 350 Angstroms with EUVE and from 912 to 1150 Angstroms with Voyager, in addition
to the optical wavelengths by our visual and CCD observers. These simultaneous
observations are important in studying the flux produced in the boundary layer between the
disk and the surface of the white dwarf, the inner disk, and the outer disk, respectively.
These measurements are also important in understanding the mechanism that causes the
outbursts.

We thank Bill Liller, Jan Hers, Danie Overbeek, Jan Smit, and observers of the Royal
Astronomical Society of New Zealand whose observations were transmitted to us by their
Director, Dr. Frank Bateson, for their very close monitoring and their early alerts of the
outburst. Their observations and the timely and rapid response by the EUVE team
produced wonderful results!

As the second part of this project, the EUVE satellite will be observing VW Hyi again in
the middle of August. A plea to our Southern Hemisphere observers - please continue to
observe this star closely, and continue to send in your observations, and alert us
immediately again when VW Hyi goes into another short outburst, expected to occur soon.

REMINDERS - GK PERSEI AND T PYXIDIS

0324+43 GK Persei. The old nova GK Per, that now has minor outbursts, is scheduled to
be observed with the XTE satellite as soon as it starts to brighten. We have a standing
request to keep a close eye on GK Per and inform astronomers in different parts of the
world when it starts to brighten. The last minor brightening of GK Per was in July 1992,
when it reached magnitude 10.3. Please inform us when GK Per becomes brighter than
magnitude 12.8. Please use the accompanying "e" and "f' scale AAVSO charts to observe
GK Per.

0900-31 T Pyxidis. The standing request from astronomers at the Space Telescope Science
Institute to keep a very close eye on T Pyx continues. We have been asked to inform them,
immediately, at any time of the day, when it goes into outburst. The last outburst of T Pyx
occurred in 1966, when it reached magnitude 7.2. We remind observers that there is a star
close to T Pyx to the southwest; observers are thus urged to be extremely careful of their
identification of T Pyx. Please use the "d" scale chart issued with AAVSO Alert Notice 179
to observe T Pyx

CHARTS AVAILABLE ON AAVSO FTP SITE

Chart links are obsolete; 11/2013 create charts using VSP at http://www.aavso.org/vsp

We have prepared electronic copies of AAVSO charts mentioned in this Alert Notice for
the following stars: V1028 Cyg, AG Dra, GK Per. They are available from our FTP site:

  ftp.aavso.org (198.116.78.2), in /pub/ alert211

The answering machine at AAVSO Headquarters is on nights and weekends for your
convenience. Please call our charge-free number (800-642-3883) 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.

When telephoning in observations, please state the name of the star, the magnitude, and
the time of the observation. Please speak clearly. The preferred time is either your local
time (be sure to state the time zone and whether it is Standard or Daylight Savings Time)
or Universal Time. You do not need to give the designation of the star. Please also
include the comparison stars you have used in making the observation.

Many thanks for your significant astronomical observations and efforts.

Good observing!

Janet A. Mattei
Director

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