Livestream Lecture - September 21, 2022

Searching for Black Holes in the Milky Way”


Jessica Lu, Associate Professor, Astronomy, UC Berkeley

The population of black holes left over from dead stars in the Milky Way is almost entirely unexplored. Only two dozen black holes are confidently known in our galaxy - all in binaries. As a result, many basic properties of black holes remain uncertain at the order of magnitude level, including the total number of black holes in the Milky Way, their masses, the fraction in binary systems, and whether black holes receive kicks at birth.

To understand these properties, we need to find and study a larger population of black holes, both in isolation and in binary systems. Gravitational lensing is opening a new window onto black holes, and the first free-floating black holes are now being discovered. Dr. Lu will present results from the search for black holes today and describe how the known number of black holes will increase 100x over the next decade.

Click here for how to view the lecture.


Membership brings with it many benefits, including access to:


Free and open to the public as well as to members, the SFAA hosts a distinguished list of guest speakers throughout the year. Our Speaker Series attracts leaders from astronomy, physics and related disciplines who share with SFAA members and the general public the latest developments from cutting-edge scientific programs. The Series invite experts from nearby NASA-Ames, Stanford, SETI, UC Berkeley, UC Santa Cruz, as well as speakers throughout the US via live-stream.


Star Parties

Each month the SFAA hosts member-only viewing atop Mount Tamalpais in Marin County. Private viewing nights like this are one of the great benefits of SFAA membership, offering peaceful viewing, with no street lights, great range of visibility from the site, (bathrooms!) and the opportunity to network with fellow astronomers. This venue is truly wonderful because it is almost always ‘above the fog’, making viewing especially ideal when the city lights are blocked by the marine layer. Many nights we can see the Milky Way in all its glory!



Special Events

Each year the SFAA hosts members-only camping and star parties at Glacier Point in Yosemite National Park in coordination with the National Park Service. Other member-only events have included night-time tours of Lick Observatory and weekend camping and star parties at the Robert Ferguson Observatory in Sonoma County. The SFAA works with schools and universities to bring telescopes to Science and Astronomy nights throughout San Francisco and Marin.


Telescope Loans

The SFAA has a number of telescopes that it loans to members who are just starting out to discover the world of astronomy and night sky viewing. The available equipment includes simple-to-use Dobsonian telescopes, computerized "go-to" telescopes, as well as numerous telescope accessories. New users are encouraged to attend member-only star parties so they can be tutored by more experienced members on how to setup their loaner scopes and to plan their viewing session.