Superoutbursts and grazing eclipses in the dwarf nova V1227 Herculis

TL;DR

This study documents superoutbursts and grazing eclipses in dwarf nova V1227 Herculis, revealing its superhump and orbital periods, and providing new insights into its accretion disc behavior during outbursts.

Contribution

First detection of grazing eclipses in V1227 Her and detailed measurement of its superhump and orbital periods.

Findings

Superoutbursts with superhumps observed in V1227 Her.

Grazing eclipses with 0.08 mag depth detected.

Measured superhump period and orbital period with specific values.

Abstract

We present photometry obtained during the 2012 May and September outbursts of the frequently outbursting dwarf nova, V1227 Her. Superhumps were present in both cases with a peak-to peak amplitude of up to 0.28 mag, showing these events to be superoutbursts. We show for the first time that the system undergoes small eclipses with a depth of up to 0.08 mag, lasting 11 to 14 min, which are likely to be grazing eclipses of the accretion disc. The September outburst was the better observed of the two and lasted at least 14 days with an outburst amplitude of approximately 4 magnitudes. The mean superhump period was Psh = 0.065103(20) d. Analysis of eclipse times of minimum gave an orbital period Porb = 0.064419(26) d, although there is some ambiguity due to the relatively short time over which the eclipses were observed. The fractional superhump period excess, epsilon, was 0.0106(7).