A Test of nova trigger theory

Document Type


Publication Date



The theory of nova eruptions is robust, and its predictions for the expanding shell are well confirmed by observations. However, the aspect of the triggering of novae has not been experimentally tested. One prediction of theory is that the total mass accumulated by the white dwarf between eruptions should be a constant for a particular system. That is, the average accretion rate times the intereruption interval should be constant for successive eruptions by a given system. For systems where the blue light is dominated by the light from the accretion disk, the average accretion rate will be proportional to the blue flux raised to power from 1.5 to 2 (as a bolometric correction). This prediction can be tested for two recurrent novae (T Pyx and U Sco) that have complete eruption records involving three or more eruptions. I have collected archival plates, brightnesses from the literature, and a large collection of my CCD magnitudes since 1987. This provides reasonable coverage for four intereruption intervals for T Pyx and three intereruption intervals for U Sco. My results are that the product of the intereruption time interval times the average bolometrically corrected flux is indeed a constant for both T Pyx and U Sco, despite large variations in the time intervals. I take this as a good confirmation of the theory of nova triggers. This result also provides a physical basis for predicting when the next eruptions will occur, with T Pyx next erupting in the year 2052 ± 3 and U Sco next erupting in the year 2009.3 ± 1.0. © 2005. The American Astronomical Society. All rights reserved.

Publication Source (Journal or Book title)

Astrophysical Journal

This document is currently not available here.