Search for associations containing young stars (SACY). VII. New stellar and substellar candidate members in the young associations

Context. The young associations offer us one of the best opportunities to study the properties of young stellar and substellar objects and to directly image planets thanks to their proximity (<200 pc) and age (≈5−150 Myr). However, many previous works have been limited to identifying the brighter, more active members (≈1 M_⊙) owing to photometric survey sensitivities limiting the detections of lower mass objects. Aims. We search the field of view of 542 previously identified members of the young associations to identify wide or extremely wide (1000−100 000 au in physical separation) companions. Methods. We combined 2MASS near-infrared photometry (J, H, K) with proper motion values (from UCAC4, PPMXL, NOMAD) to identify companions in the field of view of known members. We collated further photometry and spectroscopy from the literature and conducted our own high-resolution spectroscopic observations for a subsample of candidate members. This complementary information allowed us to assess the efficiency of our method. Results. We identified 84 targets (45: 0.2−1.3 M_⊙, 17: 0.08−0.2 M_⊙, 22: <0.08 M_⊙) in our analysis, ten of which have been identified from spectroscopic analysis in previous young association works. For 33 of these 84, we were able to further assess their membership using a variety of properties (X-ray emission, UV excess, Hα, lithium and K I equivalent widths, radial velocities, and CaH indices). We derive a success rate of 76–88% for this technique based on the consistency of these properties. Conclusions. Once confirmed, the targets identified in this work would significantly improve our knowledge of the lower mass end of the young associations. Additionally, these targets would make an ideal new sample for the identification and study of planets around nearby young stars. Given the predicted substellar mass of the majority of these new candidate members and their proximity, high-contrast imaging techniques would facilitate the search for new low-mass planets.

Salt springs from Romania exploited during early archaeological times : a new candidate for World Heritage

Our approach emphasizes on the importance of the first forms of salt springs exploitation meant to obtain recrystallized salt for the development of prehistoric human communities within the continental inlands of Europe. Although it does not compare with the monumental dimension of World Heritage, the exploitation of some salt springs in Eastern Romania goes back around 8 millennia; they may be the oldest such exploitations in the world, as proven by 14C calibrated data. What differentiates Romanian salt springs from other famous similar areas in Europe is the continuity of exploitation and utilization of natural brine. Actually, these resilient behaviours explain the creation of a whole and complex universe of salt, which also represents a unique point of reference within the intangible World Heritage. It is through this association in variable proportions between tangible (non-monumental) and intangible that these salt springs comprising the oldest traces of salt exploitation can be considered elements of World Heritage. Today, important personalities in the fields of archaeology, anthropology and history posit that salt is a major reference for the development of the entire umanity. Obviously, the breakthrough of this idea requires awareness efforts targeting, on one hand, local communities in those areas wand, on the other, national and international scientific and cultural environments concerned with the World Heritage. In this context, a proper motivation is the fact that the last two decades have witnessed an intensification of research on salt, which turned this topic one of the major themes within European archaeology and ethno-archaeology. In terms of local community awareness concerning the importance of salt springs in the economic development of a (micro) area over time, it is worth underlining mostly the specialists’ efforts of presenting this topic in the media. Moreover, the impact of a recent initiative of the two museums in the area (Piatra Neamț and Târgu Neamț)—establishing distinct sections that represent, by using museum-inspired means, both archaeological vestiges and traditional practices of natural brine exploitation and utilization—will prove its extent in time. Certain local authorities and private entrepreneurs have pinpointed that valorising tourist areas comprising the oldest traces of salt exploitation in Romania is an imminent issue. The greatest challenge is finding a balance between the civilization improvements (upgraded access roads, upgrading operating areas, etc.) and thep rotection of still-alive traditional practices of salt exploitation and use, within rural areas. Certain local authorities and private entrepreneurs have pinpointed that valorising tourist areas comprising the oldest traces of salt exploitation in Romania will become, sooner or later, an imminent issue. The greatest challenge is finding a balance between the civilization improvements (upgraded access roads, upgrading operating areas, etc.) and the protection of still-alive traditional practices of salt exploitation and use, within rural areas.