We report discovery of a bright, nearby () Sun-like star orbiting a dark object. We identified
the system as a black hole candidate via its astrometric orbital solution from the Gaia …

The presence of excess scatter in the Ly-α forest at z∼ 5.5, together with the existence of
sporadic extended opaque Gunn-Peterson troughs, has started to provide robust evidence …

Fast radio bursts (FRBs) are highly dispersed, millisecond-duration radio bursts 1, 2, 3.
Recent observations of a Galactic FRB 4, 5, 6, 7, 8 suggest that at least some FRBs originate …

Directly detecting thermal emission from young extrasolar planets allows measurement of
their atmospheric compositions and luminosities, which are influenced by their formation …

Strong gravitational lens systems with time delays between the multiple images allow
measurements of time-delay distances, which are primarily sensitive to the Hubble constant …

The mean free path of ionizing photons, λ mfp, is a critical parameter for modeling the
intergalactic medium (IGM) both during and after reionization. We present direct …

We present a new investigation of the intergalactic medium near reionization using dark
gaps in the Lyβ forest. With its lower optical depth, Lyβ offers a potentially more sensitive …

We report on work to increase the number of well-measured Type Ia supernovae (SNe Ia) at
high redshifts. Light curves, including high signal-to-noise Hubble Space Telescope data …

We present measurements of the mean and scatter of the intergalactic medium (IGM) Lyman-
α opacity at 4.9< z< 6.1 along the lines of sight of 62 quasars at z source> 5.7, the largest …

Results of the commissioning of the first Gemini Multi‐Object Spectrograph (GMOS) are
described. GMOS and the Gemini–North telescope act as a complete system to exploit a …