ow far away are the stars we see at night?
How big is the Milky Way galaxy in which we live and how is it structured?
How large is the visible universe?
How can astronomers confined to the solar system make such determinations?
Learn more about distance measurements, crucial in interpreting astronomical data that shape our view of the universe’s structure and provide calibrated estimates of the sizes and energetics of cosmic objects, during ‘Imiloa’s Maunakea Skies talk at 7 p.m. Friday (July 20) with Walter Brisken, director of the Long Baseline Array.
Distance determination played a huge role in firmly establishing that the sun is a star and that the Milky Way is but one of billions of “island universes,” two concepts with profound implications for science and philosophy. Brisken will explain distance measuring techniques and focus on the application of very long baseline interferometry, a unique radio astronomical approach using radio telescopes separated by thousands of miles to achieve superb angular resolution.
In particular, he will discuss the use of the Very Long Baseline Array in two active fields of research: determination of the detailed shape and size of the Milky Way and direct geometric measurement of the distances to galaxies to establish the value of Hubble’s Constant, the unit of measurement used to describe the expansion of the universe.
The talk will conclude with an explanation of the Hubble Constant Tension, a term used to describe the current mismatch between values of the Hubble Constant as determined in very different ways, and some possible avenues to settling this controversy.
Brisken currently serves as the director of the Long Baseline Observatory, the organization that operates the Very Long Baseline Array in Socorro, N.M.
‘Imiloa’s monthly Maunakea Skies program also includes observational highlights of the current night sky over Hawaii, with the audience able to view prominent constellations and stars visible during this time of year.
General admission is $10, or $8 for ‘Imiloa members. Pre-purchase tickets at ‘Imiloa’s front desk or by calling 932-8901.
‘Imiloa Astronomy Center is located at 600 ‘Imiloa Place in Hilo, off of Komohana and Nowelo streets at the University of Hawaii at Hilo Science and Technology Park.
For more information about ‘Imiloa or the presentation, visit www.ImiloaHawaii.org or call 932-8901.