The Hubble Space Telescope UV legacy survey of galactic globular clusters: the internal kinematics of the multiple stellar populations in NGC 2808
Numerous observational studies have revealed the ubiquitous presence of multiple stellar
populations in globular clusters and cast many difficult challenges for the study of the
formation and dynamical history of these stellar systems. In this Letter we present the results
of a study of the kinematic properties of multiple populations in NGC 2808 based on high-
precision Hubble Space Telescope proper-motion measurements. In a recent study, Milone
et al. identified five distinct populations (A–E) in NGC 2808. Populations D and E coincide�…
populations in globular clusters and cast many difficult challenges for the study of the
formation and dynamical history of these stellar systems. In this Letter we present the results
of a study of the kinematic properties of multiple populations in NGC 2808 based on high-
precision Hubble Space Telescope proper-motion measurements. In a recent study, Milone
et al. identified five distinct populations (A–E) in NGC 2808. Populations D and E coincide�…
Optical hydrogen absorption consistent with a thin bow shock leading the hot Jupiter HD 189733b
PW Cauley, S Redfield, AG Jensen…�- The Astrophysical�…, 2015 - iopscience.iop.org
Bow shocks are ubiquitous astrophysical phenomena resulting from the supersonic passage
of an object through a gas. Recently, pre-transit absorption in UV metal transitions of the hot
Jupiter (HJ) exoplanets HD 189733b and WASP12-b have been interpreted as being
caused by material compressed in a planetary bow shock. Here we present a robust
detection of a time-resolved pre-transit, as well as in-transit absorption signature around the
HJ exoplanet HD 189733b using high spectral resolution observations of several hydrogen�…
of an object through a gas. Recently, pre-transit absorption in UV metal transitions of the hot
Jupiter (HJ) exoplanets HD 189733b and WASP12-b have been interpreted as being
caused by material compressed in a planetary bow shock. Here we present a robust
detection of a time-resolved pre-transit, as well as in-transit absorption signature around the
HJ exoplanet HD 189733b using high spectral resolution observations of several hydrogen�…