Each month, I host the Public Lecture Series at the Space Telescope Science Institute in Baltimore, Maryland. Before introducing the main speaker, I present some Hubble discoveries and other astronomical findings and events called "News from the Universe".
The stories I covered for the September 6, 2016 lecture are:
-- An interesting SETI signal gets overblown on the internet
-- Mission updates from Juno and Rosetta
-- Dwarf galaxies found by their gas content
Here are the description and links to the main speaker's presentation for the September 2016 Public Lecture Series:
On the Trail of the Missing Galaxies: The Oldest Stars in the Neighborhood
Tom Brown, Space Telescope Science Institute
In the past decade, wide-field surveys have revealed a new class of ultra-faint dwarf galaxies orbiting the Milky Way and Andromeda. They are the least luminous, most dark-matter dominated, and least chemically-evolved galaxies known. These faint galaxies offer a new front in efforts to understand the missing satellite problem - the discrepancy that theory predicts many more satellite galaxies than the number of dwarf galaxies observed. As the best candidates for fossils from the early universe, the ultra-faint dwarfs are ideal places to test the physics of galaxy formation from that era. New data from the Keck Observatory and the Hubble Space Telescope provide evidence that reionization in the early universe suppressed star formation in the smallest seeds of galaxy formation, thus providing a possible explanation for the missing satellite problem.
- On the STScI webcasting page (speaker only): On the Trail of the Missing Galaxies: The Oldest Stars in the Neighborhood
- On the HubbleSiteChannel on YouTube (full event): On the Trail of the Missing Galaxies: The Oldest Stars in the Neighborhood
An archive of lecture webcasts back to 2005 is available at STScI Webcasting: STScI Public Lecture Series Archive.
Most lectures since spring 2014 are also in a HubbleSiteChannel YouTube playlist: STScI Public Lecture Series Playlist.