The evolution of satellite galaxies is shaped by their constant interaction with the circumgalactic medium surrounding central galaxies, which in turn may be affected by gas and energy ejected from the central supermassive black hole 1-6. The nature of such a coupling between black holes and galaxies is, however, much debated 7-9 and observational

Nine point sources appeared within half an hour on a region within ∼? 10 arcmin of a red-sensitive photographic plate taken in April 1950 as part of the historic Palomar Sky Survey. All nine sources are absent on both previous and later photographic images, and absent in modern surveys with CCD detectors which go several magnitudes deeper. We

I will report on our recent discovery of a wide-spread photometric variability among hot (~20,000 – 30,000 K) extreme horizontal branch (EHB) stars in Galactic globular clusters. The EHB variability is periodic, displaying single-wave, low-amplitude and ~2-50 days modulations. The variability cannot be ascribed to either binary evolution or

We present maps of the stellar streams detected in the Gaia Data Release 2 (DR2) and Early Data Release 3 (EDR3) catalogs using the STREAMFINDER algorithm. We also report the spectroscopic follow-up of the brighter DR2 stream members obtained with the high-resolution CFHT/ESPaDOnS and VLT/UVES spectrographs as well as with the medium-resolution NTT

The importance of the chromosphere in the mass and energy transport within the solar atmosphere is now widely recognized. This review discusses the physics of magnetohydrodynamic waves and instabilities in large-scale chromospheric structures as well as in magnetic flux tubes. We highlight a number of key observational aspects that have helped our

Bill Gray of Project Pluto brought to our attention an error of 0.03 in the listed latitude of our Kitt Peak telescope. While correcting the table where this occurred, we also take the opportunity to update the instrument properties and weather statistics of our remote telescopes.