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Abstract We present a study of the orbital light curves of the recurrent nova IM Normae since its 2002 outburst. The broad “eclipses” recur with a 2.46 hr period, which increases on a timescale of 1.28(16) × 10⁶yr. Under the assumption of conservative mass transfer, this suggests a rate near 10⁻⁷M_⊙yr⁻¹, and this agrees with the estimatedaccretionrate of the postnova, based on our estimate of luminosity. IM Nor appears to be a close match to the famous recurrent nova T Pyxidis. Both stars appear to have very high accretion rates, sufficient to drive the recurrent-nova events. Both have quiescent light curves, which suggest strong heating of the low-mass secondary, and very wide orbital minima, which suggest obscuration of a large “corona” around the primary. And both have very rapid orbital period increases, as expected from a short-period binary with high mass transfer from the low-mass component. These two stars may represent a final stage of nova—and cataclysmic variable—evolution, in which irradiation-driven winds drive a high rate of mass transfer, thereby evaporating the donor star in a paroxysm of nova outbursts. 

Abstract We report the detailed history of spin-period changes in five intermediate polars (DQ Herculis, AO Piscium, FO Aquarii, V1223 Sagittarii, and BG Canis Minoris) during the 30–60 yr since their original discovery. Most are slowly spinning up, although there are sometimes years-long episodes of spin-down. This is supportive of the idea that the underlying magnetic white dwarfs are near spin equilibrium. In addition to the ∼40 stars sharing many properties and defined by their strong, pulsed X-ray emission, there are a few rotating much faster (P < 80 s), whose membership in the class is still in doubt—and who are overdue for closer study.