Related papers: Deep HST Imaging in NGC 6397: Stellar Dynamics

We present deep VI photometry of stars in the globular cluster M5 (NGC 5904) based on images taken with the Hubble Space Telescope. The resulting color-magnitude diagram reaches below V ~ 27 mag, revealing the upper 2-3 magnitudes of the…

Aims. This is the second in a series of papers that attempt to unveil the kinematic structure of the Galactic bulge through studying radial velocities and proper motions. We report here ~15000 new proper motions for three low…

Magnetic activity and rotation are related to the age of low-mass main sequence stars. To further constrain these relations, we study a sample of 574 main sequence stars members of common proper motion pairs with white dwarfs, identified…

We present analyses of variability in the red giant stars in the metal-poor globular cluster NGC6397, based on data obtained with the Hubble Space Telescope. We use an non-standard data reduction approach to turn a 23-day observing run…

Aims: We present the first measurement of the proper motion and orbit of the very distant and intriguing globular cluster NCG 2419. Methods: We have combined data from HST and Gaia DR1 to derive the relative proper motions of stars in the…

We present the first detailed 3D kinematic analysis of a sample of 3133 white dwarfs that use Gaia astrometry plus radial velocities, which were measured either by Gaia or by ground based spectroscopic observations. The sample includes…

Nuclear star clusters (NSCs) are located at the photometric and dynamical centers of the majority of galaxies. They are among the densest star clusters in the Universe. The NSC in the Milky Way is the only object of this class that can be…

We report a new analysis of stellar dynamics in the Galactic centre, based on improved sky and LOS velocities for >100 stars within a few arcsec of SgrA*. Overall the motions do not deviate strongly from isotropy. For 32 stars with all 3…

We have measured the absolute proper motions of globular clusters NGC 2808, 3201, 4372, 4833, 5927 and 5986. The proper motions are on the Hipparcos system and they are the first determinations ever made for these low Galactic latitude…

Rotation is a directly-observable stellar property, and drives magnetic field generation and activity through a magnetic dynamo. Main sequence stars with masses below approximately 0.35Msun (mid-to-late M dwarfs) are fully-convective, and…

We present the serendipitous discovery of 195 extragalactic globular clusters (GCs) in one of the deepest optical images ever obtained, a 126 orbit HST/ACS imaging study of the nearby Galactic GC NGC 6397. The distant GCs are all found…

We have analyzed two epochs of HST/WFPC2 observations of the young Galactic starburst cluster in NGC 3603 with the aim to study its internal dynamics and stellar population. Relative proper motions measured over 10.15 yrs of more than 800…

We examine the spatial distribution of star clusters in NGC 628 using the statistical tool INDICATE to quantify clustering tendencies. Our sample, based on HST and JWST observations, is the most complete to date, spanning ages from 1 Myr to…

We present the results of a photometric survey for variable stars in the central region of the nearby globular cluster NGC 6397.Time series photometry was obtained for 30 variable objects. The sample includes 12 new objects, of which 6 show…

A common proper motion survey of M dwarf stars within 8 pc of the Sun reveals no new stellar or brown dwarf companions at wide separations (~100-1400 AU). This survey tests whether the brown dwarf ``desert'' extends to large separations…

With the Wide Field Planetary Camera 2 (WFPC2) on the Hubble Space Telescope, we have discovered in M4 (NGC 6121, C 1620-264) the first extensive sequence of cooling white dwarfs seen in a globular cluster. Adopting a distance modulus of…

We present the first results of a large ACS Survey of Galactic globular clusters. This Hubble Space Telescope (HST) Treasury project is designed to obtain photometry with S/N > ~10 for main sequence stars with masses > ~0.2Msun in a sample…

We report our study of features at the observed red end of the white dwarf cooling sequences for three Galactic globular clusters: NGC\,6397, 47\,Tucanae and M\,4. We use deep colour-magnitude diagrams constructed from archival Hubble Space…

We use Hubble Space Telescope (HST) to reach the end of the white dwarf (WD) cooling sequence (CS) in the solar-metallicity open cluster NGC 6819. Our photometry and completeness tests show a sharp drop in the number of WDs along the CS at…

By combining high spatial resolution and wide-field spectroscopy performed, respectively, with SINFONI and FLAMES at the ESO/VLT we measured the radial velocities of more than 600 stars in the direction of NGC 6388, a Galactic globular…