Bedtime Astronomy

NASA's SPHEREx telescope has created the first complete 3D infrared sky map using 102 wavelengths invisible to human eyes. This revolutionary dataset tracks galaxy evolution and the chemical building blocks of life across hundreds of millions of celestial objects.Unlike telescopes studying narrow fields, SPHEREx scans the entire cosmos every six months, measuring distances through spectroscopy to reveal how the universe expanded after the Big Bang.The freely available data helps scientists understand how our universe became habitable, with multiple scans planned over two years to enhance observation quality.

A baffling cosmic event, designated AT2025ulz, was detected by LIGO and Virgo and is now considered a candidate for a never-before-seen phenomenon: a superkilonova. This oddball event, which took place 1.3 billion light-years away, initially resembled a kilonova—an explosion caused by the merger of two dense neutron stars. Kilonovae are known to forge the heaviest elements, such as gold and uranium.However, after about three days, AT2025ulz started to look more like a supernova, brightening, turning blue, and showing hydrogen in its spectra. The gravitational-wave data indicated that at least one of the colliding objects was less massive than a typical neutron star.Astronomers hypothesize that this "superkilonova" was a kilonova spurred by a prior supernova blast. The leading theory suggests that a rapidly spinning, massive star went supernova, birthing two "forbidden" sub-solar mass neutron stars. These newborn stars may have then spiraled together and merged, creating a kilonova. This scenario would explain why the event displayed features of both a supernova and a kilonova, potentially obscuring the initial merger. This potential cosmic rarity challenges our understanding of stellar death and the formation of heavy elements.

This episode explores a new five-year astronomical survey of the Large and Small Magellanic Clouds using the 4MOST spectrograph on the VISTA Telescope.Led by the Leibniz Institute for Astrophysics Potsdam, the 1001MC project will collect high-resolution spectra from nearly 500,000 stars to reveal their motions, chemical composition, and history.We discuss how this data could answer long-standing questions about the formation and evolution of these dwarf galaxies, with full operations starting in 2026.

New James Webb Space Telescope observations reveal that a seemingly ordinary young galaxy, seen just 800 million years after the Big Bang, hides a rapidly growing, dust-enshrouded supermassive black hole.Infrared data from JWST’s MIRI instrument challenge established models of black hole and galaxy co-evolution and suggest that many similar objects may remain undetected across the universe.

Discover the fastest cosmic explosion ever recorded! We explore GRB 230307A, a gamma-ray burst detected by NASA's Fermi Space Telescope that reached 99.99998% of light speed—a breakthrough led by University of Alabama graduate researchers.Learn how this ultrarelativistic jet from a neutron star merger revealed an associated kilonova, offering new insights into how heavy elements like tellurium form in our universe.This episode highlights cutting-edge space science and the crucial role of student researchers in unlocking cosmic mysteries. Key topics: gamma-ray bursts, neutron star mergers, kilonova, heavy element formation, relativistic physics