[en] Two radio sources near M3 are identified as quasi-stellar sources

[en] The dynamically zoned pulsation code developed by Castor, Davis, and Davison has been used to recalculate the Goddard model and to calculate three other Cepheid models with the same period (9.8 days). This family of models shows how the bumps and other features of the light and velocity curves change as the mass is varied at constant period. This study, with a code that is capable of producing reliable light curves, shows again that the light and velocity curves for 9.8-day Cepheid models with standard homogeneous compositions do not show bumps like those that are observed unless the mass is significantly lower than the ''evolutionary mass.'' The light and velocity curves for the Goddard model presented here are similar to those computed independently by Fischel, Sparks, and Karp. They should be useful as standards for future investigators

[en] The light and color curves, the characteristics and evolution of the spectrum of the supernova prove that it belongs to the type Ia, but with one significant peculiarity: all its spectral features appear blueshifted when compared with other supernove of the same type. The interpretation and origin of such anomaly remains still rather controversial. Contrary to recent claims, the photometry of this supernova does not seem peculiar

[en] A spectrum of the Supernova SN 1974-NGC 4414 between 3100-5000 A with a dispersion of 67 A.mm^-1 near maximum light has been obtained. This spectrum shows the characteristic features of all type I supernovae: wide absorption bands, large expansion velocity and a clear decrease of the ultraviolet radiation (lambda < 3600 A)

No abstract available

[en] A Comment on the Letter by T. J. M. Boyd and R. Ondarza-Rovira [Phys. Rev. Lett. 98, 105001 (2007)]. The authors of the Letter offer a Reply

[en] Infrared spectrophotometry with resolution Δlambda/lambda approximately equal to 0.015 over the wavelength range 2 to 14 μm is presented for a wide variety of stars of the conventional spectral sequence. The progression of the strength of discrete spectral features due to gaseous molecules in the stellar atmospheres as well as those features attributable to circumstellar grains is illustrated and discussed

[en] Additional material from the archival photograph collection at the Harvard Observatory was used to derive an improved light curve for HZ Her during its optical OFFs. The full amplitude of the double sinusoidal variation, ΔB = 0.187 +- 0.054 mag

[en] In this communication, we will illustrate an algorithm for automatic element identification in LIBS spectra which takes inspiration from the vector space model applied to text retrieval techniques. The vector space model prescribes that text documents and text queries are represented as vectors of weighted terms (words). Document ranking, with respect to relevance to a query, is obtained by comparing the vectors representing the documents with the vector representing the query. In our case, we represent elements and samples as vectors of weighted peaks, obtained from their spectra. The likelihood of the presence of an element in a sample is computed by comparing the corresponding vectors of weighted peaks. The weight of a peak is proportional to its intensity and to the inverse of the number of peaks, in the database, in its wavelength neighboring. We suppose to have a database containing the peaks of all elements we want to recognize, where each peak is represented by a wavelength and it is associated with its expected relative intensity and the corresponding element. Detection of elements in a sample is obtained by ranking the elements according to the distance of the associated vectors from the vector representing the sample. The application of this approach to elements identification using LIBS spectra obtained from several kinds of metallic alloys will be also illustrated. The possible extension of this technique towards an algorithm for fully automated LIBS analysis will be discussed.

No abstract available