[vsnet-alert 11545] TT Ari faint: QPOs still present

[Ivan Andronov]

TT Ari faint: QPOs still present

In the [vsnet-alert 11543] ,
MAEDA Yutaka reported that "TT Ari is faint" (12.9), what was confirmed by
Hiroyuki Maehara [vsnet-alert 11544] (13.0).

Alexej Baklanov continued observations of the star starting from September
(Crimean Astrophysical Observatory, 38 cm)
The light curve in R (variable-"d" from Goetz 1987,
http://www.konkoly.hu/cgi-bin/IBVSpdf?2823) is shown in an attached figure.
Although the
linear fit shows an apparent trend of  0.011(8) mag/day, i.e. NOT statistically
significant during 3 subsequent night of observations. The V mag
during the recent night (observations are still continued) is 12.84-13.32.

The light curves 
http://uavso.pochta.ru/TT_Ari091010.jpg
exhibit quasi-periodic oscilations, which are characteristic
for the "negative superhump" state, contrary to the "positive
superhump" state (cf. Kim et al., http://cdsads.u-strasbg.fr/abs/2009A%26A...496..765K)

This "negative superhump state" was observed also during the optical set
simultaneous with the Suzuku satellite
http://cdsads.u-strasbg.fr/abs/2009ATel.2122....1A

So, till now, there was no switch to the "positive superhump state", although
the mean brightness decreased by ~2 mag compared with usual
maximum state.

Further monitoring of this interesting object is needed; in R or VRVR time
series for all available nights.

Alexej Baklanov
Crimean Astrophysical Observatory, Ukraine

Ivan Andronov
Odessa National Maritime University, Ukraine
temporararily also (SAIA fellowship) Astronomical Institute, Slovak Academy of
Sciences, Slovakia