Stargazing Lecture

Friday, April 16, 2021
7:00pm to 9:00pm
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Online Event
Endless Hunt for Black Holes
Wenbin Lu, David and Ellen Lee Postdoctoral Scholar Research Associate, Department of Theoretical Astrophysics, Caltech,
  • Public Event

Because this is an online event, the in-person stargazing that normally follows events in this series will not be possible.

Join the YouTube Livestream here:

7:00–7:30 p.m. - Virtual Lecture
7:30–9:00 p.m. - Virtual Panel Q&A and Discussion

The existence of black holes is one of the most striking predictions of Einstein's theory of general relativity, but it has been a century-long journey to test whether these bizarre objects are actually formed in our universe. This question has been investigated in several different ways: by considering the evolution and eventual collapse of massive stars; by observing stellar motion around a "dark mass concentration" at the center of our own galaxy; by examining X-ray and radio emission from gas falling into "dense massive objects"; by viewing light bent by the gravitational potential of free-floating "invisible objects"; and most recently, by collecting gravitational waves from colliding "compact massive binaries". I will show that black holes predicted by general relativity have passed all these checks with scrutiny, and then I will discuss what additional ways astronomers can further test the existence of black holes.

About the Series

Stargazing Lectures are free lectures at a public level followed by a Q&A panel and guided stargazing with telescopes (weather permitting). All events are held at the Cahill Center for Astronomy and Astrophysics at Caltech. No reservations are needed. Lectures are 30 minutes; stargazing and panel Q&A last 90 minutes. Stay only as long as you want.

Stargazing is only possible with clear skies, but the lecture and panel Q&A takes place regardless of weather.

For directions, weather updates, and more information, please visit:

For more information, please contact Cameron Hummels by email at [email protected].