Related papers: Gaia DR2 white dwarfs in the Hercules stream
Extensive surveys of star-forming regions with Spitzer have revealed populations of disk-bearing young stellar objects. These have provided crucial constraints, such as the timescale of dispersal of protoplanetary disks, obtained by…
Context: Open clusters (OCs) provide homogeneous samples of white dwarfs (WDs) with known distances, extinctions, and total ages. The unprecedented astrometric precision of \textit{\textit{Gaia}} allows us to identify many novel OC--WD…
The presence of infrared excess flux observed in white dwarfs (WDs) is related to the existence of debris disks or substellar companions. These systems provide important clues in the study of extrasolar planetary material and binary…
We present a study of the three dimensional structure, kinematics, and age distribution of the Orion OB association, based on the second data release of the Gaia satellite (Gaia DR2). Our goal is to obtain a complete picture of the star…
White dwarfs (WDs) offer unrealized potential in solving two problems in astrophysics: stellar age accuracy and precision. WD cooling ages can be inferred from surface temperatures and radii, which can be constrained with precision by high…
We present a wavelet-based algorithm to identify dwarf galaxies in the Milky Way in ${\it Gaia}$ DR2 data. Our algorithm detects overdensities in 4D position--proper motion space, making it the first search to explicitly use velocity…
We use a sample of ~350 RR Lyrae stars with radial velocities and Gaia DR2 proper motions to study orbital properties of the Hercules-Aquila Cloud (HAC) and Virgo Over-density (VOD). We demonstrate that both structures are dominated by…
Gaia will identify several 1e5 white dwarfs, most of which will be in the solar neighborhood at distances of a few hundred parsecs. Ground-based optical follow-up spectroscopy of this sample of stellar remnants is essential to unlock the…
The observational signature of core crystallization of white dwarfs has recently been discovered. However, the magnitude of the crystallization-powered cooling delay required to match observed white dwarfs is larger than predicted by…
Gaia Data Release 2 revealed detailed structures of nearby stars in phase space. These include the Hercules stream, whose origin is still debated. Most of the previous numerical studies conjectured that the observed structures originate…
We use Gaia Data Release 2 (DR2) to place 252 Herbig Ae/Be stars in the HR diagram and investigate their characteristics and properties. For all known Herbig Ae/Be stars with parallaxes in Gaia DR2, we collected their atmospheric parameters…
The second data release from ESA's Gaia mission has revealed many ridge-like structures in the velocity distribution of the Milky Way. We show that these can arise naturally from winding transient spiral structure that is commonly seen in…
The publications of Gaia DR2 and DR3 have brought major improvements in stellar astrometry and photometry, particularly regarding the description of the white dwarf sequence. Notably, Gaia DR2 enabled the detection of variability in white…
Stellar streams are ubiquitous in the Galactic halo and they can be used to improve our understanding of the formation and evolution of the Milky Way as a whole. The so-called Monoceros Ring might have been the result of satellite…
We present kinematics of a sample of 398 DA white dwarfs from the SPY project (ESO SN Ia Progenitor surveY) and discuss kinematic criteria for a distinction of thin disk, thick disk, and halo populations. This is the largest homogeneous…
The GSC-II white dwarf survey was designed to identify faint and high proper motion objects, which we used to define a new and independent sample of cool white dwarfs. With this survey we aim to derive new constraints on the halo white…
The true nature of the Hyades and Sirius superclusters is still an open question. In this contribution, we confront Eggen's hypothesis that they are cluster remnants with the results of a kinematic analysis of more than 6000 K and M giants…
In very young clusters, stellar age distribution is the empirical proof of the duration of star formation (SF) and of the physical mechanisms involved in the process. We derived accurate stellar ages for the cluster NGC6530, associated with…
The third data release of Gaia was the first to include orbital solutions assuming non-single stars. Here, we apply the astrometric triage technique of Shahaf et al. to identify binary star systems with companions that are not single…
We have performed a search for halo white dwarfs as high proper motion objects in a second epoch WFPC2 image of the Groth-Westphal strip. We identify 24 high proper motion objects with mu > 0.014 ''/yr. Five of these high proper motion…