Welcome to Space Sundays on the Deep dAIve podcast!

This is our weekly slot where human curiosity meets AI execution to look past the clouds and stare directly into the great beyond. We’re independent science enthusiasts learning out loud, openly leveraging AI models to help us parse complex astronomy data and write our scripts.

In this episode, we explore a mind-boggling Draft paper published on June 17, 2026, from astronomers at Yale University, Princeton, and the Dragonfly Focused Research Organization. For decades, dark matter has been considered the fundamental invisible glue that holds all galaxies together. But astronomers using data from the Keck Observatory's Cosmic Web Imager (KCWI) have officially constrained the mass of DF9, a unique galaxy on a cosmic trail within the NGC 1052 field. Its stellar velocity dispersion is measured to match what is expected from its stellar mass alone. This discovery confirms that—just like its famous neighbors DF2 and DF4—dark matter is absolutely not required to explain its kinematics. We unpack how a massive "bullet dwarf" collision might have separated this entire trail of galaxies from their dark matter, shaking up modern cosmology.

Read the Original Research Paper:

• Draft Version: June 17, 2026 (AASTeX Style)

• Article Title: A Third Galaxy Missing Dark Matter along a Trail of Galaxies in the NGC 1052 Field

• Lead Authors: Michael A. Keim, Pieter van Dokkum, Zili Shen, Shany Danieli, and Imad Pasha (Yale University / Princeton / Dragonfly FRO)