BEGIN:VCALENDAR VERSION:2.0 PRODID:-//AIP Calendar//www.aip.de// BEGIN:VEVENT SUMMARY:Colloquium | Ralf Klessen (ITA\, Heidelberg) DTSTART:20260219T133000Z DTEND:20260219T143000Z DTSTAMP:20260524T230940Z UID:www.aip.de-2360 CATEGORIES:Scientific CATEGORIES:Scientific Talk CATEGORIES:Public CATEGORIES:Colloquium CONTACT:Ewald Puchwein DESCRIPTION:Speaker: Ralf Klessen (ITA\, Heidelberg)\nTitle: The astronomi cal odds for a starry night\, or how unique is our place in the Universe?\ nAbstract: The star-filled night sky that inspired Vincent van Gogh’s St arry Night has guided human navigation\, art\, and scientific inquiry thro ughout history. Yet it remains unclear whether such a view is typical acro ss the Milky Way or the result of unusually favorable cosmic circumstances . Using stellar catalogues\, Gaia-based three-dimensional reconstructions of interstellar dust\, and high-resolution simulations of a Milky Way–li ke galaxy\, we quantify how the local interstellar medium regulates the vi sibility of stars for an Earth-like observer. A central aspect of this inv estigation is our knowledge of our local Galactic environment. Our solar s ystem is currently located in the middle of a large cavity of tenuous\, ho t gas\, the Local Bubble. We believe this structure originated from the en ergy and momentum released by 15–20 supernova explosions over the past 1 5 million years or so\, which displaced the nearby interstellar medium\, l ike a snowplow pushing snow from the street to pile it up along the sidewa lk. This environment may not be unique and there are likely thousands of s imilarly large bubbles in the Milky Way\, a view that is supported by rece nt observations with the James Webb Space Telescope in nearby galaxies. Be tter understanding the Local Bubble is important\, not only because it def ines our place in the Milky Way and many of the nearby star-forming region s are associated with the walls of the Local Bubble\, but also because ess entially all extragalactic observations pass through this cavity and are t hus subject to veiling effects from the bubble walls. Accurately assessing the impact of this foreground\, for example\, is important for the scient ific success of future experiments measuring the cosmic microwave backgrou nd and its polarization properties at high angular resolution. In this pre sentation\, I will report the current efforts at Heidelberg University to address this challenge and share some of the many failures and the (much f ewer) successes we had.\n LOCATION:AIP\; Kirch building\, Conference room END:VEVENT END:VCALENDAR