Related papers: Monoceros OB4: a new association in Gaia DR2
We present recent results from our ongoing large scale variability survey of the Orion OB1 Association. In an area of ~ 25 square degrees we have unveiled new populations of low-mass young stars over a range of environments, and ages from…
We study the region around Collinder 121 (Cr 121) using newly available 6-dimensional data from the Gaia DR3 catalogue. Situated in the third quadrant, near the galactic plane, Collinder 121 lies in the region of Canis Major centred around…
We present the analysis of the stellar content of NGC~2282, a young cluster in the Monoceros constellation, using deep optical $BVI$ and IPHAS photometry along with infrared (IR) data from UKIDSS and $Spitzer$-IRAC. Based on the stellar…
OB associations are primordial tracers of star formation and Galactic structure. Originally defined about 80 years ago, their historical membership lists have been superseded thanks to the precise astrometry from ESA's \textit{Gaia}'s…
Young field stars are hardly distinguishable from older ones because their space motion rapidly mixes them with the stellar population of the Galactic plane. Nevertheless, a careful target selection allows for young stars to be spotted…
We report the discovery of 25 new open clusters resulting from a search in dense low galactic latitude fields. We also provide, for the first time, structural and astrophysical parameters for the new findings and 34 other recently…
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…
We investigate the structure of our Galaxy's young stellar disc by fitting the distribution functions (DFs) of a new family to five-dimensional Gaia data for a sample of $47\,000$ OB stars. Tests of the fitting procedure show that the young…
We present 3-dimensional kinematical observations of the massive OB association Cygnus OB2 to identify the mechanisms responsible for disrupting young star clusters. The picture revealed by these observations is of a highly-substructured,…
Aims. We are searching for new open clusters or moving groups in the Solar neighbourhood. Methods. We used the Gaia-TGAS catalogue, cut it into narrow proper motion and parallax slices and searched for significant spatial over-densities of…
Two star-forming regions are studied: the young embedded open cluster vdB 130 and the protocluster neighbourhood observed in the head and tail of the cometary molecular cloud located in the wall of the expanding supershell surrounding the…
In this review I discuss different theories of the formation of OB associations in the Milky Way, and provide the observational evidences in support of them. In fact, the second release of Gaia astrometric data (April 2018) is…
Cygnus OB2 provides a unique insight into the high-mass stellar content in one of the largest groups of young massive stars in our Galaxy. Although several studies of its massive population have been carried out over the last decades, an…
We present and discuss photometric optical data in the area of the OB association Sco OB1 covering about 1 squared degree. UBVI photometry is employed in tandem with Gaia DR2 data to investigate the 3 dimensional structure and the star…
We perform a comprehensive CO study toward the Monoceros OB1 (Mon OB1) region based on the MWISP survey at an angular resolution of about $50''$. The high-sensitivity data, together with the high dynamic range, shows that molecular gas in…
OB associations are unbound groups of young stars made prominent by their bright OB members, and have long been thought to be the expanded remnants of dense star clusters. They have been important in astrophysics for over a century thanks…
OB associations, as an intermediate stage between Galactic clusters and field stars, play an important role in understanding the star formation process, early stellar evolution, and Galactic evolution. In this work, we construct a large…
We report the discovery of 31 new open clusters (OCs) identified in \textit{Gaia}~DR3 data through a systematic search over 220 adjacent $1^\circ\times1^\circ$ fields towards the Galactic anticentre, in the direction of the Perseus arm gap.…
In this work we improve a previously published method to calculate in a reliable way the radius of an open cluster. The method is based on the behaviour of stars in the proper motion space as the sampling changes in the position space. Here…
The past two decades have seen dramatic progress in our knowledge of the population of young stars of age <200 Myr that lie within 150 pc of the Sun. These nearby, young stars, most of which are found in loose, comoving groups, provide the…