Related papers: The low-mass pre-main-sequence population of Sco O…
We have used ESO telescopes at La Silla and the Hubble Space Telescope (HST) in order to obtain accurate B,V,I CCD photometry for the stars located within 200" (~= 2 half-mass radii, r_h = 1.71') from the center of the cluster NGC 6101.…
Recent evolutionary computations predict that a few percent of massive OB stars in binary systems should have a dormant BH companion. Despite several reported X-ray quiet OB+BH systems over the last couple of years, finding them with…
I have used high-precision photometry and astrometry from the early installment of the third data release of Gaia (EDR3) to perform a survey for members of the stellar populations within the Sco-Cen complex, which consist of Upper Sco,…
We have searched for visual binaries with projected separations in the range 200-3000 AU (0.1"-1.5") among a sample of 96 stars in the massive young NGC 6611 cluster, 60 of them being subsequently identified as high probability cluster…
The Upper-Scorpius association is the OB association nearest to the Sun (145 pc). Its young age (5 Myr) makes it an ideal place to search for low-mass stars and brown dwarfs, as these objects should be relatively bright. We have performed a…
Open clusters belonging to star-forming complexes are the leftovers from the initial stellar generations. The study of these young systems provides constraints to models of star formation and evolution as well as to the properties of the…
The stellar group surrounding the Be (B1Vpe) star 25 Orionis was discovered to be a pre-main-sequence population by the Centro de Investigaciones de Astronomia (CIDA) Orion Variability Survey and subsequent spectroscopy. We analyze Sloan…
Over the past years, the lambda-Orionis cluster has been a prime location for the study of young very low mass stars, substellar and isolated planetary mass objects and the determination of the initial mass function and other properties of…
Context: Recent near-infrared data have contributed to the discovery of new (obscured) massive stellar clusters and massive stellar populations in previously known clusters in our Galaxy. These discoveries lead us to view the Milky Way as…
Cepheus B (Cep B) molecular cloud and a portion of the nearby Cep OB3b OB association, one of the most active regions of star formation within 1 kpc, has been observed with the ACIS detector on board the Chandra X-ray Observatory. We detect…
We present a general overview and the first results of the SUMO project (a SUrvey of Multiple pOpulations in Globular Clusters). The objective of this survey is the study of multiple stellar populations in the largest sample of globular…
We present results of our large scale, optical, multi-epoch photometric survey of ~180 square degrees across the Orion OB1 association, complemented with extensive follow up spectroscopy. We map and characterize in an uniform way the…
The supergiant ionized shell SMC-SGS 1 (DEM 167), located in the outer Wing of the Small Magellanic Cloud (SMC), resembles structures that originate from an energetic star-formation event and later stimulate star formation as they expand…
The Milky Way's most luminous, young and massive (M > 10^4 Msun) star clusters and OB associations have largely evaded detection despite knowledge of their surrounding H II regions. We search for these clusters and associations within the…
We present adaptive optics (AO) near-infrared observations of the core of the Tr 14 cluster in the Carina region obtained with the ESO multi-conjugate AO demonstrator, MAD. Our campaign yields AO-corrected observations with an image quality…
The FUSE far-ultraviolet interstellar spectra toward seven targets in NGC 6231 show that the molecules H_2, HD, and CO as well as various atomic species are distributed in several clouds. The main absorption component found on the sight…
We report here results from a Chandra ACIS observation of the stellar populations in and around the Messier 17 H II region. The field reveals 886 sources, 771 of which have stellar counterparts in infrared images. In addition to…
We present near-infrared JHKs and narrow-band H2(1-0) photometric observations of the W51A region, obtained with GTC EMIR, aiming to characterize its young stellar population and provide mass estimates for individual cluster members and the…
We present a new analysis of the stellar population of the Orion Nebula Cluster (ONC) based on multi-band optical photometry and spectroscopy. We study the color-color diagrams in BVI, plus a narrow-band filter centered at 6200A, finding…
We present the results of a proper motion wide-field near-infrared survey of the entire Upper Sco (USco) association (~160 square degrees) released as part of the UKIRT Infrared Deep Sky (UKIDSS) Galactic Clusters Survey (GCS) Data Release…