MIT Professor Emeritus Hale Van Dorn Bradt PhD '61 of Peabody, Massachusetts, formerly of Salem and Belmont, beloved husband of Dorothy A. (Haughey) Bradt, passed away on Thursday, Nov. 14 at Salem Hospital, surrounded by his loving family. He was 93. Bradt, a longtime member of the Department of Physics, worked primarily in X-ray astronomy with NASA rockets and satellites, studying neutron stars and black holes in X-ray binary systems using rocket-based and satellite-based instrumentation. He was the original principal investigator for the All-Sky Monitor instrument on NASA's Rossi X-ray Timing Explorer (RXTE), which operated from 1996 to 2012. Much of his research was directed toward determining the precise locations of celestial X-ray sources, most of which were neutron stars or black holes. This made possible investigations of their intrinsic natures at optical, radio, and X-ray wavelengths. 'Hale was the last of the cosmic ray group that converted to X-ray astronomy,' says Bruno Rossi Professor of Physics Claude Canizares. 'He was devoted to undergraduate teaching and, as a postdoc, I benefited personally from his mentoring and guidance.'...

Every galaxy has a supermassive black hole at its center, much like every egg has a yolk. But sometimes, hens lay eggs with two yolks. In a similar way, astrophysicists like us who study supermassive black holes expect to find binary systems ' two supermassive black holes orbiting each other ' at the hearts of some galaxies. Black holes are regions of space where gravity is so strong that not even light can escape from their vicinity. They form when the core of a massive star collapses on itself, and they act as cosmic vacuum cleaners. Supermassive black holes have a mass a million times that of our Sun or larger. Scientists like us study them to understand how gravity works and how galaxies form. Figuring out whether a galaxy has one or two black holes in its center isn't as easy as cracking an egg and examining the yolk. But measuring how often these binary supermassive black holes form can help researchers understand what happens to galaxies when they merge. In a new study, our team dug through historical astronomical data dating back over a hundred years. We looked for light emitted from one galaxy that showed signs of harboring a binary supermassive black hole system....

In April 2019, a group of astronomers from around the globe stunned the world when they revealed the first image of a black hole ' the monstrous accumulation of collapsed stars and gas that lets nothing escape, not even light. The image, which was of the black hole that sits at the core of a galaxy called Messier 87 (M87), revealed glowing gas around the center of the black hole. In March 2021, the same team produced yet another stunning image that showed the polarization of light around the black hole, revealing its magnetic field. The "camera" that took both images is the Event Horizon Telescope (EHT), which is not one singular instrument but rather a collection of radio telescopes situated around the globe that work together to create high-resolution images by combining data from each individual telescope. Now, scientists are looking to extend the EHT into space to get an even sharper look at M87's black hole. But producing the sharpest images in the history of astronomy presents a challenge: transmitting the telescope's massive dataset back to Earth for processing. A small but powerful laser communications (lasercom) payload developed at MIT Lincoln Laboratory operates at the high data rates needed to image the aspects of interest of the black hole....