Related papers: A Measurement of Diffusion in 47 Tucanae
We constructed for the first time a stellar density profile of 47 Tucanae (47 Tuc) out of $\sim$ 5.5 times its tidal radius ($r_t$) using high-quality deep $BV$ photometry. After carefully considering the influence of photometric errors,…
The main goal of this work was to measure the masses and radii of white dwarfs that belong to widely separated, common proper motion binaries with non-degenerate companions. These can be assessed, independently from theoretical mass-radius…
We analyse the cooling of white dwarfs in the globular cluster 47 Tucanae to look for evidence of axion emission affecting the rate of white dwarf cooling. If axions exist and couple to electrons, then axions could be produced at an…
Using a sample of 43 suitable local subdwarfs with newly acquired BVI photometry, we apply our main sequence fitting method to the metal rich Globular Cluster 47 Tucanae. Fitting in 2 colour planes, we find an apparent distance modulus of…
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…
Using the Spitzer IRAC camera we have obtained mid-IR photometry of the red giant branch stars in the Galactic globular cluster 47 Tuc. About 100 stars show an excess of mid-infrared light above that expected from their photospheric…
White dwarfs are stellar embers depleted of nuclear energy sources that cool over billions of years. These stars, which are supported by electron degeneracy pressure, reach densities of 1e7 grams per cubic centimetre in their cores. It has…
We have employed deep far-UV observations secured with the Solar Blind Channel of the Advanced Camera for Surveys onboard the Hubble Space Telescope to search for hot companions to five blue stragglers stars (BSSs) showing significant…
Although the internal structure of white dwarfs is considered to be generally well understood, the source and entity of viscosity is still very uncertain. We propose here to study white dwarf viscous properties using short period (< 1 hr),…
A test of Newton's law of gravity in the low acceleration regime using globular clusters is presented. New results for the core collapsed globular cluster NGC 7099 are given. The run of the gravitational potential as a function of distance…
Observations at 70 microns with the Spitzer Space Telescope have detected several stellar systems within 65 pc of the Sun. Of 18 presumably young systems detected in this study, as many as 15 have 70-micron emission in excess of that…
Motivated by recent observations that suggest a low density of old stars around the Milky Way supermassive black hole, models for the nuclear star cluster are considered that have not yet reached a steady state under the influence of…
We report the first wideband observations of pulsars C, D and J in the globular cluster 47Tucanae (NGC 104) using the Ultra-Wideband Low (UWL) receiver system recently installed on the Parkes 64 m radio telescope. The wide frequency range…
Using JWST Near Infrared Camera (NIRCam) images of the globular cluster 47 Tucanae (or NGC 104), taken at two epochs just 7 months apart, we derived proper-motion membership down to $m_{\rm F322W2} \sim 27$. We identified an intriguing…
We obtain stringent constraints on the actual efficiency of mass loss for red giant branch stars in the Galactic globular cluster 47 Tuc, by comparing synthetic modeling based on stellar evolution tracks with the observed distribution of…
Aims. We present the results of the analysis of five observations of the globular cluster 47 Tucanae (47 Tuc) with eROSITA (extended Roentgen Survey with an Imaging Telescope Array) on board Spektrum-Roentgen-Gamma (Spektr-RG, SRG). The aim…
We report on X-ray emission from members of the recently discovered Tucanae association, a group of stars with youth signatures and similar space motion. The Tucanae association is the nearest known region of recent star formation (at 45…
We report the detection of ionized intracluster gas in the globular cluster 47 Tucanae. Pulsars in this cluster with a negative period derivative, which must lie in the distant half of the cluster, have significantly higher measured…
We present high resolution Hubble Space Telescope ultraviolet spectroscopy of the dwarf nova EK TrA obtained in deep quiescence. The Space Telescope Imaging Spectrograph data reveal the broad Ly-alpha absorption profile typical of a…
Observations of the spatial distribution and kinematics of young stars in the Galactic centre can be interpreted as showing that the stars occupy one, or possibly two, discs of radii ~0.05-0.5 pc. The most prominent (`clockwise') disc…