Search for binary central stars of the SMC PNe

The Optical Gravitational Lensing Experiment (OGLE), originally designed to search for microlensing events, provides a rich and uniform data set suitable for studying the variability of certain types of objects. We used the OGLE data to study the photometry of central stars of planetary nebulae (PNe) in the Small Magellanic Cloud (SMC). In particular, we searched for close binary central stars with the aim to constrain the binary fraction and period distribution in the SMC. We also searched for PNe mimics and removed them from the PNe sample. We identified 52 counterparts of PNe in the SMC in the I-band images from the OGLE-II and OGLE-III surveys. We analysed the time-series photometry of the PNe. Spectra of the photometric variables were obtained to constrain the nature of the objects or search for additional evidence for binarity. Eight variables were found. Of these, seven objects are PNe mimics, including one symbiotic star candidate. One close binary central star of PN with a period of 1.15 or 2.31 day was discovered. The obtained binary fraction for the SMC PNe and the observational biases are discussed in terms of the OGLE observations.Comment: Accepted for publication in A&A. 7 pages and 7 figures, table 4 is only available at the CD

Comparison Between the Sonic-Sys System and Inlay in II Class

In everyday dental practice we often face the problem of class II restorations. Large caries create serious problems with regard to obtaining correct contact points, marginal fit (expecially in the gingival area) and good resin polymerisation. In such cases usage of the Sonic-Sys system and inlays seems to be the best solution. The aim of this poster is to present a manual of the Sonic-Sys system, as well as comparison of the Empress II and Sonic-Sys system inlays in class II restorations. The color, marginal fit, contouring and articulating points were evaluated in clinical tests. The surfaces of the preparation were examined in SEM differences between those made by means of Sonic- Sys and standard diamond burs. The results present advantages and disadvantages of both methods. The best choice is to consider the appropriate method after clinical examination and treatment planning in each individual case