Astron. Astrophys. Suppl. Ser. 133, 211-216

Photometry of the dust nova V705 Cassiopeiae

L. Hric¹ - K. Petrík² - Z. Urban¹ - D. Hanzl³

Send offprint request: L. Hric

1 - Astronomical Institute of the Slovak Academy of Sciences, 059 60 Tatranská Lomnica, The Slovak Republic
e-mail: hric@ta3.sk
2 - Department of Mathematics, Informatics and Physics, Pedagogical Faculty, University of Trnava, 918 43 Trnava,
The Slovak Republic
e-mail: astropet@ta3.sk
3 - N. Copernicus Observatory and Planetarium, 616 00 Brno, The Czech Republic

Received April 9; accepted June 10, 1998

Abstract:

We present the results of our UBV photoelectric photometry of V705 Cas (Nova Cassiopeiae 1993) obtained at the Skalnaté Pleso, Stará Lesná, Hlohovec and Brno Observatories. The observations cover the light curve development of this nova over its stages of dust formation and disappearance of the envelope. The results of the light curve analysis are presented. We have also used the visual brightness estimates of V705 Cas by the members of the VSNET network as an auxiliary data set in order to determine the nova's brightness behaviour as accurately as possible. The basic parameters of the brightness decline of the nova t_2,B= 40 d, t_2,V = 33 d, t_3,B = 63 d, t_3,V = 61 d, with the accuracy not worse than one day, were obtained on the basis of our light curves. The relevant value of $M_{B}= (-7.27 \pm{0.3})$ mag and the value $M_{V}= (-7.32\pm{0.22})$ mag in the maximum of brightness were derived. The corresponding value of the mass of the white dwarf component of the presumable underlying nova binary is $M_{\rm WD}= (0.79\pm{0.06})$ $M_{\odot}$.The colour excess at brightness maximum is E_B-V= 0.56 mag and the corresponding value of the distance $r= (1.67\pm{0.34})$ kpc. This value of the distance is very probably underestimated due to the strong extinction by the dust envelope of the nova. The general problem of the use of statistical calibrations as well as that of the distance determination for dust novae is discussed.

Key words: stars: novae, cataclysmic variables -- stars: individual: V705 Cas