19,254 research outputs found
On invariant sets in Lagrangian graphs
In this exposition, we show that a Hamiltonian is always constant on a
compact invariant connected subset which lies in a Lagrangian graph provided
that the Hamiltonian and the graph are smooth enough. We also provide some
counterexamples for the case that the Hamiltonians are not smooth enough.Comment: 4 page
The periods of the intermediate polar RX J0153.3+7446
We present the first optical photometry of the counterpart to the candidate
intermediate polar RX J0153.3+7446. This reveals an optical pulse period of
2333s +/- 5s. Reanalysis of the previously published ROSAT X-ray data reveals
that the true X-ray pulse period is probably 1974s +/- 30s, rather than the
1414 s previously reported. Given that the previously noted orbital period of
the system is 3.94 h, we are able to identify the X-ray pulse period with the
white dwarf spin period and the optical pulse period with the rotation period
of the white dwarf in the binary reference frame, as commonly seen in other
intermediate polars. We thus confirm that RX J0153.3+7446 is indeed a typical
intermediate polar.Comment: 4 pages, submitted to A&A Letter
Meeting report: Thunderstorms
Copyright @ 2007 Royal Meteorological Societ
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