T CrB: Brightest Nova in Generations
By Dr. Brad Schaefer
T Coronae Borealis is a recurrent nova with observed eruptions in the years 1217, 1787, 1866, and 1946, plus a fifth eruption widely expected sometime in the year 2024. This peak will presumably get to V=1.7 (the same as the discovery by Mr. A. S. Kamenchuk in 1946), and be the brightest novae seen since 1946 (for T CrB itself). T CrB displays several unique and mysterious effects in its visual light curve, and it plays into the Grand Challenge Type Ia supernova progenitor problem. To solve these with the 2024 eruption, small telescope photometry and spectroscopy is the way to answer the big questions. For example, if T CrB displays bright [Ne III] lines three weeks after the peak, then the most-prominent single-degenerate models suffer a big failure. And the myriad of visual measures will define the orbital phase for measuring the apparently-huge orbital period change across the nova event. Already, AAVSO spectroscopy has solved the case of the `pre-eruption dip' (as discovered by L. Peltier), with this turning out to be a turning-off of the pre-eruption high state.
NASA’s Space Launch System: Big Science on the Big Rocket
By Dr. John Blevins
NASA Space Launch System (SLS) Chief Engineer Dr. John Blevins will discuss SLS—a super-heavy lift launch vehicle that is helping return astronauts to the Moon through NASA’s Artemis campaign. In addition to the success of the Artemis I mission, he will also present SLS’s capabilities for interplanetary science missions, telescope missions, and even a concept interstellar mission.
Image: NASA.
The Precision Frontier of Dark Matter Constraints from Direct Acceleration Measurements
By Dr. Sukanya Chakrabarti
For over a century, our understanding of dark matter has hinged on kinematic estimates derived from static snapshots of stellar positions and velocities. However, these methods are inaccurate for a time-dependent potential, and there are now many lines of observational evidence that show that our Galaxy has had a highly dynamic history. Recent technological advancements now empower us to carry out precision time-series measurements of the acceleration of stars that live within the gravitational potential of our Galaxy. I will discuss our comprehensive observational strategy to directly measure Galactic accelerations. Central to this discussion is our recent analysis of compiled pulsar timing data from which we were able to measure the Galactic acceleration for the first time, and derive fundamental Galactic parameters. Discernible differences in sub-structure exist among popular dark matter models on small scales, presenting testable nuances. I will discuss the potential for measuring dark matter sub-structure in the Milky Way by leveraging the diverse set of techniques we have developed, including pulsar timing, eclipse timing, and extreme-precision radial velocity observations. I will review initial results from our multi-pronged observing campaign, and end by discussing synergies between Galactic dark matter constraints and constraints on theories of gravity.
Image: ESO/S. Brunier, CC BY 4.0, via Wikimedia Commons.
