[vsnet-alert 1265] New Algol variable; call for confirmation

[Ulrich Bastian <s01@ix.urz.uni-heidelberg.de>]

Dear colleagues and friends,

please post the following message on your alert boards
(AAVSO alert or newsflash, VSNET alert, BAV homepage, ...).
Thank you.

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Klaus Bernhard of Linz (Austria) apparently discovered a
hitherto unknown Algol variable by repeatedly taking
CCD pictures of a field in Aquila. The finding and the
probable period can be confirmed by two predicted minima
in the next few days  -  as well as by observations at
other times, of course. The star is of magnitude 10.5, the
amplitude is about 0.5 mag (unfiltered CCD). Since the
amplitude may be expected to be larger at shorter
wavelengths, even visual observers may be successful. A
suitable comparison star is just a few arcmin away.

Details are given below. Please report all results to the
two following addresses (we do not regularly receive AAVSO
and VSNET alerts etc.) :

s01@ix.urz.uni-heidelberg.de  (U. Bastian)
klaus.bernhard@ooe.gv.at      (K. Bernhard)

Kind regards,
Ulrich Bastian

Astronomisches Rechen-Institut
Moenchhofstr. 14
D-69120 Heidelberg
Germany

Tel  +49-6221-405-152 or -405-0
Fax        "      297

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Star: GSC 1062-33, 19h 53m 40.22s +09d 23' 51.0"
      (J2000, epoch 1991.25, TYCHO Catlg.)
      Tycho B = 11.6, V = 10.9 (+/- 0.1).
      No information in SIMBAD and ADS, no variability
      detected by Tycho (star too faint for that).

Variability: Usually mag 10.5 on unfiltered CCD images.
             Three ("main") minima of 0.5 mag depth and
             about 7 hours duration. One ("secondary")
             minimum of about 0.2 mag depth.

Times of minima: 10-09-1997 ~22    UT "main"
                 23-09-1997  20.45 UT "main"
                 06-10-1997  18.52 UT "main"
                 27-09-1997  22.05 UT "secondary"

Interpretation: Algol variable of 12.92 days period
                with highly excentric secondary minimum.
                Period of 12.92/2 = 6.46 days cannot be
                excluded, but would surprisingly lead to
                an equally excentric secondary minimum.

Prediction: Using T(min I)= JD 2450728.29 + 12.92*E,
            an observable main minimum is predicted for

            *****      19-10-1997, 17 UT,    *****

            and a secondary minimum for

            *****      23-10-1997, 18 UT.    *****

            These are observable from Europe (starting
            during dawn) and the Middle East. Observers
            at other longitudes can help to exclude
            other periods. Since the observational season
            for Aquila will end soon, observations are
            urgent. If the period is correct, these are
            the last ones observable from these longitudes,
            and practically no minima wil be observable
            from Japan and US before the conjunction with
            the sun.

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