Alert Notice 317: Request to monitor 0103+59 HT Cas, 0809-76 Z Cha, 1004-69 OY Car AND Request to monitor 2147+13 LS Peg AND Request to monitor 1743-12 V378 Ser (Nova Ser 2005)

June 3, 2005

1. REQUEST TO MONITOR 0103+59 HT CAS, 0809-76 Z CHA, 1004-69 OY CAR
3. REQUEST TO MONITOR 1743-12 V378 SER (NOVA SER 2005)

1. REQUEST TO MONITOR 0103+59 HT CAS, 0809-76 Z CHA, 1004-69 OY CAR

Our colleagues Drs. Christopher Mauche, Lawrence Livermore National Laboratory, Peter Wheatley, University of Leicester, and Koji Mukai, NASA Goddard Space Flight Center, have obtained time on the ESA XMM-Newton X-ray multi-mirror telescope (XMM) to observe HT Cas, Z Cha, or OY Car in outburst. They have requested our assistance in monitoring these stars closely so we can inform them promptly when any of them go into outburst. Very prompt notification is essential, because the satellite requires 2-4 days to move to the target after the observations are triggered, and the superoutbursts of OY Car and Z Cha last only about 10 days, while the HT Cas outbursts last only a little more than 2 days.

The windows when XMM can observe these stars are given below:

HT Cas 2005-07-10 to 2005-09-06 and 2006-01-07 to 2006-03-02
Z Cha 2005-04-05 to 2006-03-20
OY Car 2005-05-31 to 2005-09-24 and 2005-12-02 to 2006-03-20

As you can see from this table, the observing windows for Z Cha and OY Car are already open. In fact, observations reported directly to Dr. Wheatley and to the AAVSO indicate that OY Car is declining from an outburst (possibly a superoutburst) that appears to have begun on May 26.

AAVSO observers are asked to monitor HT Cas, OY Car, and Z Cha closely from now through at least a month after the last observing window closes, and to notify Headquarters immediately if HT Cas brightens to magnitude 15.5 or brighter, or OY Car or Z Cha brightens to 14.5 or brighter. Both visual and CCD observations are encouraged.

PLEASE HELP US BY SUBMITTING YOUR OBSERVATIONS - BOTH POSITIVE AND NEGATIVE - TO THE AAVSO QUICKLOOK FILE AS SOON AFTER YOU MAKE THEM AS POSSIBLE. If you are not registered to submit observations electronically, please go to the WebObs page ( [obsolete link]) on the AAVSO website and fill out the registration form there.

AAVSO charts for HT Cas and OY Car are available from the AAVSO website via the chart search engine (  [obsolete link; create charts using VSP at ]). Please type the star name into the form there and you will be shown all available charts for that star. RASNZ 'b', 'd', and 'e' [obsolete links] scale charts are available for Z Cha. If you are unable to download any of these charts, they may be requested from AAVSO Headquarters.


As announced by Aaron Price and Gary Walker in CCD Views #337 [broken link] on May 26, "Dr. Darren Baskill, University of Leicester, has requested optical observations of LS Peg (currently suspected as being a DQ Her nova-like) to coincide with upcoming observations by the XMM Newton X-Ray observatory.

"Observations are requested from now until July 8. Intensive, time series observations are requested 12 hours before and also during the actual XMM observation which is scheduled for June 6, 2005 from 08:55 to 21:34 (UT). So we need time series coverage from:

20:55 June 5 (UT) to 21:34 June 6 (UT)

"Use an Ic filter if you have one and a V filter if not. Set your exposure time for maximum precision. This is a bright system (V~12) so it should be easy to get an SNR of 100. The latest ASAS-3 observation is:

May 13.4185 V=12.324 +/- 0.097

"A new AAVSO f-scale chart has been prepared and is here: [obsolete link; create charts using VSP at ]

"Arne Henden has calibrated the field this week in BVRI so we will be adding R and Ic magnitudes to the chart in a couple of weeks."

For additional information on Dr. Baskill's research, please see CCD Views #337. Many thanks for your assistance.


Dr. Alon Retter, Penn State University, has requested our assistance in obtaining observations of the recently discovered nova V378 Ser (Nova Serpentis 2005). First detected on ASAS images obtained March 18, N Ser 05 was announced on April 4, 2005, in IAU Circular 8505 by G. Pojmanski.

As the following selected CCDV observations submitted to the AAVSO by Shawn Dvorak, Clermont, FL, show, N Ser 05 reached a peak brightness on April 4 and has been fluctuating since then: APR 04.4417 UT, 11.56; 17.4114, 13.08; 29.4063, 11.97; MAY 10.4052, 14.22; 16.3202, 12.61; 19.3708, 13.87; 29.3157, 13.27.

Please monitor V378 Ser over the coming weeks as the nova fades and report your observations to AAVSO Headquarters. Both visual and CCD observations are encouraged. Please use the chart created by Reinder J. Bouma, available at the following URL:


We encourage observers to submit observations via our web site (online data submission tool WebObs), or by email in AAVSO format to If you do not have AAVSO Observer Initials, please contact Headquarters so we may assign them to you. The answering machine at AAVSO Headquarters is on nights and weekends; use our charge-free number (888-802-STAR = 888-802-7827) to report your observations, or report them via fax (617-354-0665).

Many thanks for your valuable astronomical contributions and your efforts.

Good observing!

Elizabeth O. Waagen
Senior Technical Assistant



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