Stargazing Lecture on Cosmic Fireworks: How Astronomers Explore the Changing Sky

Date/Time
Date(s) - 08/22/2025
8:00 pm - 10:00 pm

Location
Cahill Center For Astronomy And Astrophysics

Category(ies)

• Technology & Science

Comet Nishimura, Aug. 19, 2023 (Photo – Dan Bartlett)

Enjoy a free stargazing lecture followed by a Q&A panel and guided stargazing with telescopes (weather permitting).

The Universe evolves over the course of billions of years—a timescale almost incomprehensible to humans—but there are some things in the night sky that change much faster. Spectacular explosions of massive stars dying, pulsing stars, and comets and asteroids drifting through our Solar System are all examples of changes in the sky that happen over the course of weeks, months, or years. These events which cause new sources of light to appear and disappear in the sky are called “astronomical transients.”

In this talk, participants will explore the history of astronomical transients: including observations of an exploding star by Chinese astronomers in 1054 CE, the search for comets over the centuries, and the first large-scale surveys of the sky using the Mt. Wilson and Palomar observatories. The lecture will also cover the next-generation efforts to detect these events using Caltech’s very own Zwicky Transient Facility (ZTF) and the brand new Vera Rubin Observatory, which will reveal millions of new asteroids and supernovae across the sky in the coming years.

The lecture will be from 8:00 – 8:45 pm, followed by a panel Q&A and guided stargazing until 9:45 pm. Stargazing is dependent on clear weather, but the lecture and Q&A happen regardless. The event will occur in-person, with the lecture and Q&A additionally live-streamed on YouTube.

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 and are free and open to all. No reservations are needed. Lectures are 30 minutes; stargazing and panel Q&A last 60 minutes. Stay only as long as you want.

Stargazing is only possible with clear skies, but the lecture and panel Q&A take place regardless of weather. For directions, weather updates, and more information, visit this website. For more information, contact Cameron Hummels by email at chummels@caltech.edu.