The time-dependent rebrightenings in classical novae outbursts: a late-time episodic fuel burning?

Abstract

A significant fraction of novae exhibit a series of rebrightenings on the decline branch of their light curves. We use visual observations to study this phase in several well-observed novae. We find that these rebrightenings are isolated flare-like events on otherwise smooth light curves and we show that in most novae in our sample the time intervals between consecutive flares gradually increase as a geometric series; rebrightenings are equally spaced in logarithmic time. We also find a correlation between the rate of increase in the time between rebrightenings with the speed class of the nova in the sense that slower novae tend to increase the time intervals faster. We attribute these rebrightenings to instabilities in the envelope hydrogen burning and we mention other cases of such timing pattern in astronomy and natural sciences in general.

5 pages, 3 figures, accepted to ApJL

References in corpus (5)

• A Universal Decline Law of Classical Novae
• "Anomalous" Optical GRB Afterglows are Common: Two z~4 Bursts, GRB 060206 and 060210
• Optical and X-Ray Observations of GRB 060526: A Complex Afterglow Consistent with An Achromatic Jet Break
• Optical and Supersoft X-ray Light Curve Models of Classical Nova V2491 Cygni: A New Clue to the Secondary Maximum
• On the behaviour of stellar winds that exceed the photon-tiring limit

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