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		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 220 (April 3,1996)

OBSERVATIONS OF 1058+38 MARKARIAN 421 WITH HUBBLE SPACE TELESCOPE

Astronomers at Space Telescope Science Institute have requested our assistance in the 
multiwavelength observing campaign they have planned for the object Markarian 421. 
Their campaign will utilize four space satellites - XTE (X-ray Timing Explorer), ISO 
(Infrared Satellite Observatory), IUE (International Ultraviolet Explorer), and ROSAT 
(ROentgen SATellite) - and will take place from April 7 through April 20. Visual 
observations, unfiltered CCD observations, and, particularly, B and V filtered CCD 
observations will be very important to the successful correlation of the multiwavelength 
data.

Please monitor Mark 421 closely from April 7 through April 20, and report your 
observations to AAVSO Headquarters. An e' scale AAVSO preliminary chart of Mark 
421 is enclosed for your use.

OUTBURST OF 0324+43 GK PERSEI

The old nova GK Per, presently undergoing a minor outburst (see AAVSO Alert Notice 219), 
has reached maximum brightness after a slow rise, as the following recent observations 
indicate:

Feb 28.5000 UT, 12.0, J. McKenna, Upper Montclair, NJ; 28.838, 12.1, G. Poyner, Birmingham, England; 
28.977, 12.0, P. Schmeer, Bischmisheim, Germany, 29.0188, 12.0, G. Chaple, Townsend, MA; 29.0764, 12.1, A. 
Dill, Wichita, KS; 29.1500, 12.2, R. Royer, Lakewood, CA; 29.8, 12.0, M. Verdenet, Bourbon-Lancy, France; 
29.866, 12.1, M. Westlund, Uppsala; 29.87, 12.2, J. Ripero, Madrid, Spain; Mar 1.0257, 11.8, McKenna; 1.1229, 
12.0, S. O'Conner, Montreal North, Quebec; Canada; 1.4667, 11.8, S. Sakuma, Kawasaki, Japan; 1.52, 11.6, G. 
Dyck, Assonet, MA; 1.819, 12.1, A. Diepvens, Balen, Belgium; 1.857, 11.5, Ripero; 1.9785, 12.0, M. Biesmans, 
Essen, Belgium; 2.052, 12.0, J. Holtz, Coraopolis, PA; 2.1764, 11.9, T. Burrows, Novato, CA; 2.2174, 12.0, W. 
Dillon, Missouri City, TX; 2.4069, 11.8, Sakuma; 2.787, 11.9, Schmeer; 2.85, 11.5, J. Gunther, St. Oze, France; 
3.1139, 11.9, M. Heifner, Denver, CO; 3.4014, 11.8, Sakuma; 3.52, 11.8, Dyck; 3.790, 11.7, Diepvens; 3.801, 11.8, 
Schmeer; 3.812, 11.5, Ripero; 4.0132, 11.8, Chaple; 4.0146, 12.0, McKenna; 4.1458, 11.9, Burrows; 4.4035, 11.9, 
Sakuma; 5.0035, 11.9, McKenna; 5.0139, 11.9, Chaple; 5.4104, 11.9, Sakuma; 5.8264, 11.8, M. Kohl, Laupen, 
Switzerland; 6.1146, 12.0, Royer; 6.1708, 11.9, Burrows; 6.7993, 11.9, Kohl; 7.7868, 12.0, Kohl; 7.807, 11.4, 
Schmeer; 7.8576, 11.7, Westlund; 8.0292, 11.9, M. Komorous, London, Ontario, Canada; 8.0424, 11.7, R. Hays, 
Worth, IL; 8.1083, 11.6, Dillon; 8.1792, 11.5, Burrows; 8.785, 11.5, Diepvens; 8.7861, 11.6, Kohl; 8.81, 11.6, B. 
Granslo, Fjellhamar, Norway; 8.811, 11.5, Schmeer; 8.85, 11.0, Verdenet; 8.8715, 11.6, Westlund; 9.1056, 11.8, 
Dill; 9.789, 11.6, Dill; 9.815, 11.6, Schmeer; 9.844, 11.1, R. Szabo, Ajka, Hungary; 9.85, 11.1, Verdenet; 9.882, 
11.5, Granslo; 10.0090, 11.8, McKenna; 10.0313, 11.0, Chaple; 10.0444, 11.0, Connor; 10.0507, 11.3, Hayes; 
10.0549, 11.3, Komorous; 10.0986, 11.6, R. Harvan, Leonardstown, MD; 10.1056, 11.2, W. Bailey, Toney, Al; 
10. 1264, 11.6, Dillon; 10. 1403, 11.0, Heifner; 10. 1479, 11.8, Dill; 10.7785, 11.6, Kohl; 10.814, 11.2, Schmeer; 
10.901, 11.6, Diepvens; 10.9715, 11.1, Biesmans; 11.029, 11.2, McKenna; 11.0347, 11.1, O'Conner; 11.0576, 11.2, 
Hayes; 11. 1375, 11.6, Bailey, 11.806, 11.2, Schmeer; 11.869, 11.6, Diepvens; 11.98, 11.1, Granslo; 12.0396, 11.0, 
Komorous; 12.0417, 11.3, Hayes; 12.1285, 11.0, Ditlon; 12.7882, 11.5, Kohl; 12.821, 11.2, Schmeer; 12.894, 10.9, 
Granslo; 13.008, 11.2, McKenna; 13.1049, 11.0, Heifner, 13.810, 11.0, Diepvens; 13.8479, 10.9, Kohl; 14.796, 11.1, 
Diepvens; 14.802, 11.0, Schmeer;15.2813, 10.9, Royer;15.817,11.0, Schmeer; 16.0542, 11.1, C. Stephan, Sebring, 
FL; 16.1028, 10.7, Heifner; 16.1139, 11.5, W. Kaminski, Fairburn, SD; 16.1750, 10.9, Burrows; 17.0215, 10.7, 
Komorous; 17.13, 10.7, K. Millyard, Toronto, Ontario, Canada; 17.4229,10-5, J. Griese, Rocky Hill, CT; 17.827, 
10.9, Poyner; 17.8854, 10.6, K. Medway, Southampton, England; 18.016, 11.08 CCDV, R. Zissell, S. Hadley, 
MA; 18.0521, 11.2, Stephan; 18.1632, 11.0, Burrows; 18.847, 11.0, L. Jensen, Farum, Denmark; 18.9736, 10.7, 
Westlund; 19.0042, 10.6, Chaple; 19.0139, 10.7, O'Conner; 19.03, 10.8, Dyck; 19.1979, 10.7, G. Hanson, Cave 
Creek, AZ; 19.8, 10.7, Gunther; 19.801, 11.2, Jensen; 19.823, 10.9, P. Skalak, Czech Republic; 20.0090, 10.7, 
O'Conner; 20.1792, 11.0, Hanson; 20.788, 10.5, Skalak; 20.80, 10.5, Verdenet; 21.0910, 10.7, Dill; 21.1632, 10.6, 
Burrows; 22.0910, 10.5, Hayes; 22.1424, 10.1, Dillon; 22.1618, 10.5, Burrows; 23.1056, 10.3, Dillon; 23.1708, 10.6, 
Burrows; 23.8, 10.5, Verdenet; 23.812, 10.4, Schmeer, 24.0285, 10.7, Komorous; 24.1674, 10.4, Burrows; 24.815,
10.4, Schmeer; 25.0014, 10.6, McKenna; 25.83, 10.2, G. Comello, Groningen, Netherlands; 26-808,10.5, Jensen; 
26.82, 10.3, Comello; 27.0167, 10.3, McKenna; 27.1722, 10.6, Hanson; 27.833, 10.2, Medway; 29.0333, 10.6, 
O'Conner; 29.1701, 10.4, Burrows; 30.0306, 10.7, Komorous; 30.1576, 10.4, Burrows; 31.1083, 10.3, Dillon; 
31.1625,10.6:, Burrows; Apr 1.897, 10.8, Poyner.

With the assistance of the above observations, the XTE satellite has observed GK Per four 
times. It is scheduled to make one last observation, during the outburst decline. Please 
continue to monitor GK Per and report your observations to AAVSO Headquarters.

1813+49 AM HERCULIS MAY BE FADING FROM HIGH STATE

An international observing campaign on the prototype magnetic cataclysmic variable AM 
Her was announced in AAVSO Alert Notice 218. Activity in this star was announced in 
AAVSO Newsjlash No. 7, and the observations reported there as well as those received 
since indicate that AM Her may be fading from its bright, high state, as the following 
observations indicate:

Mar 6.5625 UT, 13.2, R. Royer, Lakewood, CA; 14.4285, 13.3, M. A. Komorous, London, 
Ontario, Canada; 16.3993, 13.3, Komorous; 20.1701, 13.0, M. Kohl, Laupen, Switzerland; 
22.1396, 13.3:, S. Brincat, Sangwann, Malta; 24.4021, 13.3, J. Griese, Rocky Hill, CT; 
25.3153,13.4, Griese; 27.028,13.2, L. T. Jensen, Farum, Denmark; 27.339,13.50 CCDV, R. 
Zissell, South Hadley, MA; 27.3743,13.5, Komorous; 28.226,13.70 CCDV, Zissell; 30.3243, 
13.7, Komorous; 30.365,13.8 CCDV, Zissell; 31.274,13.5 CCDV, Zissell.

If AM Her is indeed fading, multiwavelength observations will be carried out, so your 
observations at this time are extremely important. Please monitor AM Her and report 
your observations to AAVSO Headquarters.

1834-23 V348 SAGITTARII TO BE OBSERVED WITH HUBBLE SPACE TELESCOPE

The interesting R CrB variable V348 Sgr, presently at its maximum brightness of 
approximately magnitude 12.1 as reported by D. Overbeek, Edenvale, South Africa, is 
scheduled to be observed at the end of April with the Hubble Space Telescope.

Please monitor V348 Sgr and report your observations to AAVSO Headquarters, 
particularly if you see it beginning to decline.

CHARTS AVAILABLE ON AAVSO FTP SITE AND AAVSO HOME PAGE

Electronic copies of the AAVSO chart of Mark 421 mentioned in this Alert Notice are 
available from our FT? site:

ftp.aavso.org (198.116.78.2), in /pub/alert220

The charts have also been placed on our home page:

http:/ /www.aavso.org

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.

Many thanks for your valuable astronomical contributions and your efforts.

Good observing!

Janet A. Mattei 
Director