Clusters

It is thought that a large fraction of stars are born in clusters and it is thus important to study these. Because many are short-lived, one needs to study young ones. Moreover, open clusters represent likely a single population of stars that formed simultaneously and from the same chemical environment and as such provide useful means to constrain the evolution of stars and the formation and evolution of binaries. In particular, clusters allow to identify the outcome of binary evolution that are blue straggler stars. This has now become even more true with the data from Gaia, which is a real game changer.

Most recently, with Tereza Jerabkova, we identified the 800 pc long tidal tails of the Hyades star cluster, which was also the subject of an ESA press release. In this paper, we also likely discovered the epicyclic overdensities from an open star cluster. We then explored also the tidal arms of the cluster NGC 752, showing that they were much longer than previously thought. This also highlights the importance of dedicated, artisanal studies, compared to industrial ones.

Over the years, I have been working on several other aspects related to these issues, including uncovering a 260 pc wide, 35-Myr-old filamentary relic of star formation, finding a stellar relic filament in the Orion star-forming region, or debusking multiple populations and wide binaries in the Orion Nebula Cluster and discovering a super lithium-rich red-clump star in the open cluster Trumpler 5.

I also organised a workshop and edited a book on the Ecology of Blue Straggler Stars.

Here is a list of some of my publications related to clusters:

• Degree of stochastic asymmetry in the tidal tails of star clusters
• A tale of caution: the tails of NGC 752 are much longer than claimed
• The 800 pc long tidal tails of the Hyades star cluster
• Uncovering a 260 pc wide, 35-Myr-old filamentary relic of star formation
• A plague of magnetic spots among the hot stars of globular clusters
• A Study of the Blue Straggler Population of the Old Open Cluster Collinder 261
• A stellar relic filament in the Orion star-forming region
• When the tale comes true: multiple populations and wide binaries in the Orion Nebula Cluster
• A sextet of clusters in the Vela OB2 region revealed by Gaia
• A tale of three cities. OmegaCAM discovers multiple sequences in the color-magnitude diagram of the Orion Nebula Cluster
• The mass-ratio and eccentricity distributions of barium and S stars, and red giants in open clusters
• A super lithium-rich red-clump star in the open cluster Trumpler 5
• Chemical abundance analysis of the old, rich open cluster Trumpler 20
• The Central Blue Straggler Population in Four Outer-halo Globular Clusters
• The structure of young star clusters