RR Lyrae stars seen from space

RR Lyrae stars for a long time had the reputation of being rather simple pulsators, but the advent of high-precision space photometry has meanwhile changed this picture dramatically. This article summarizes the results obtained for two remarkable Blazhko RR Lyrae stars and discusses how our view of RR Lyrae stars has changed since the availability of ultra-precise satellite photometry as it is obtained by CoRoT and Kepler. Both stars, CoRoT 105288363 and V445 Lyrae, show a multitude of phenomena that were impossible to observe from the ground, either because of the small amplitude of the effect, or because uninterrupted long-term monitoring was required for a detection. Not only was it found that strong and irregular cycle-to-cycle changes of the Blazhko effect can occur, and that seemingly chaotic phenomena need to be accounted for when modeling the Blazhko effect, but also a rich spectrum of low-amplitude frequencies was detected in addition to the fundamental radial pusation in RRab stars. The so-called period doubling phenomenon, higher radial overtones and possibly also non-radial modes make RR Lyrae stars more multifaceted than previously thought. This article presents the various aspects of irregularity of the Blazhko effect, questioning its long-standing definition as a "periodic modulation", and also discusses the low-amplitude pulsation signatures that had been hidden in the noise of observations for centuries.Comment: 4 pages, 2 figures, accepted for publication in Astronomical Notes, proceedings of "The New Era of Helio- and Asteroseismology", 2012. 05. 20-25. Obergurgl (A

Breadth and characteristic sequence of nilpotent Lie algebras

The notion of breadth of a nilpotent Lie algebra was introduced by B. Khuhirun, K.C. Misra and E. Stitzinger and used to approach problems of classification up to isomorphism. In the present paper, we study this invariant in terms of characteristic sequence, another invariant introduced by M. Goze and J.M. Ancochea-Bermudez. This permits to complete the determination of Lie algebras of breadth 2 and to begin the work for Lie algebras with breadth greater than 2.Comment: 12 page

Supporting Student Success: A Governor's Guide to Extra Learning Opportunities

Provides a policy guide for improving opportunities for children outside of school. Includes strategies for engaging new business and community partners, accessing federal funding, and connecting out-of-school learning to education reform efforts