Z Cha and its Superhumps

• Autorzy: Smak J.
• Języki publikacji: EN

Abstrakty

EN

The superhump eclipse light curves are re-determined for five eclipses of Z Cha (E54036, E54037, E67877, E74693, E74694) observed by Warner and O'Donoghue (1988) during its superoutbursts. Qualitatively they are similar to those obtained by O'Donoghue (1990), showing two local minima at φ≈-0.05 and 0.04. Arguments are then presented which imply that the first minimum is not due to an occultation but is produced by absorption effects in the overflowing parts of the stream. The location of the superhump light source (SLS) determined from the analysis of the second minimum coincides with the trajectory of the overflowing parts of the stream. The light curve of the sixth eclipse (E77878) could be simply decomposed into its disk and superhump components. The location of SLS, obtained from the analysis of the SLS eclipse light curve, coincides in this case with the position of the standard hot spot. This implies that superhumps are due to modulated mass transfer rate resulting in periodically enhanced dissipation of the kinetic energy of the stream.

Słowa kluczowe

EN

accretion; accretion disks; novae; cataclysmic variables; Stars: dwarf novae; Stars: individual: Z Cha

• Wydawca: Copernicus Foundation for Polish Astronomy
• Czasopismo: Acta Astronomica
• Rocznik: 2009
• Tom: Vol. 59, No. 1
• Strony: 109--120
• Opis fizyczny: Bibliogr. 8 poz., rys., wykr.

Twórcy

autor

Smak J.

• N. Copernicus Astronomical Center, Polish Academy of Sciences, ul. Bartycka 18, 00-716 Warsaw, Poland

Bibliografia

• Hessman, F.V. 1999, ApJ, 510, 867.
• Kunze, S., Speith, R., and Hessman, F.V. 2001, MNRAS, 322, 499.
• O’Donoghue, D. 1990, MNRAS, 246, 29.
• Smak, J. 1994, Acta Astron., 44, 45.
• Smak, J. 2007, Acta Astron., 57, 87.
• Smak, J. 2008, Acta Astron., 58, 55.
• Warner, B., and O’Donoghue, D. 1988, MNRAS, 233, 705.
• Wood, J.H., Horne, K., Berriman, G., and Wade, R.A. 1989, ApJ, 341, 974.