Large spectroscopic surveys require automated methods of analysis. This paper explores the use of k-means clustering as a tool for automated unsupervised classification of massive stellar spectral catalogs. The classification criteria are defined by the data and the algorithm, with no prior physical framework. We work with a representative set of

We present an archaeoastronomical analysis of the orientations of six protohistoric sanctuaries and public buildings located in archaeological sites of the south of the Iberian Peninsula (Coria del Rio, El Carambolo, Saltillo, Mesa de Setefilla, Tejada la Vieja and El Oral). This study, the first of its kind conducted on a sample of Early Iron Age

As a system currently in the state of merging with the Milky Way -- and therefore a prototype for substructures that participate in the hierarchical build-up of our galaxy -- the structure of the Sagittarius (Sgr) dSph system is of particular interest. The APOGEE survey is ideally suited for the study of Sgr stars because of its ability to sample

Dwarf elliptical galaxies (dEs) are the most common galaxy class in dense environments. They are also a surprisingly inhomogenous class, which has made it challenging both to relate different dE subtypes to each other, as well as place the whole class in the larger context of galaxy assembly and (trans)formation processes. Here we will show the

A small fraction of the telluric standards observed as part of the SDSS-III APOGEE survey have been discovered to be B-type emission line stars, many of which are likely to be classical Be stars. The H I Brackett line profiles of these systems are being characterized to study the properties of the circumstellar disks associated with these objects

The formation of collimated outflows or jets in planetary nebulae (PNe) is not well understood. There is no evidence for active accretion discs in PNe, making it difficult to decide which of the several proposed jet formation scenarios may be correct. A handful of wide binary central stars of PNe are known to have accreted carbon and slow neutron