We use Hubble Space Telescope (HST) and ground-based imaging to study the multiple populations of 47 Tucanae (47 Tuc), combining high-precision photometry with calculations of synthetic spectra. Using filters covering a wide range of wavelengths, our HST photometry splits the main sequence into two branches, and we find that this duality is

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Different nuclear burning regimes are predicted on accreting neutron stars (NSs) depending mainly -but not only- on the amount of mass accreted on the NS per unit time and area. We present X-ray observations of a rapidly accreting 11 Hz pulsar in the globular cluster Terzan 5 that reveal four distinct thermonuclear bursting regimes. In one of them

HerMES, the Herschel/SPIRE extragalactic GTO program, is detecting high redshift sources which were once the domain of high redshift QSOs. Our most spectacular object discovered to date, from over 50 square degrees of survey area with rich ancillary data, is an extraordinarily bright submillimeter galaxy with a confirmed redshift of z=6.337, which

A logarithmic spiral is a prominent feature appearing in a majority of observed galaxies. This feature has long been associated with the traditional Hubble classification scheme, but historical quotes of pitch angle of spiral galaxies have been almost exclusively qualitative. We have developed a methodology, utilizing Two-Dimensional Fast Fourier