CfA Public Observatory Night - Henrietta Swan Leavitt Edition

IMPORTANT: Below is the latest update for the event tonight, including details on telescope viewing

Dear avid stargazers!

The May 2025 Public Observatory Night is tonight! If you can no longer make it and would like to cancel your tickets, please cancel/refund your tickets, or get in touch, as we have MANY people on a waiting list. There is now a way to refund your tickets yourself (or feel free to reach out).

Reminder, there's now an optional earlier start time of 7:00 PM (30 minutes earlier than originally planned). We’re thrilled to announce that the Harvard Plate Stacks team will be joining us and showcasing a selection of special glass plate artifacts—some of which were personally examined by Henrietta Leavitt during her time at the Harvard College Observatory from 1901 to 1921. In addition, we’re delighted to welcome visual artist and author Anna Von Mertens, who will also be attending the event. Anna is the author of Attention Is Discovery: The Life and Legacy of Astronomer Henrietta Leavitt (MIT Press, 2024), an expansion of her 2018–2019 exhibition Measure presented at the Harvard Radcliffe Institute.

If you’d like to attend the artifact exhibition and meet Anna Von Mertens along with our guest speakers, Louise Breuval and Caroline Huang, we recommend arriving for a 7:00 PM start. As originally scheduled, the talks will begin at 7:30 PM. Guests are welcome to join for a 7 or 7:30 start time. Tickets are required.

WEATHER UPDATE: The sky is expected to be mostly cloudy or overcast tonight - unfortunately. We therefore need to cancel telescope viewing, and hope we have clearer skies for next time. However, a tour of our esteemed Great Refractor Telescope built in 1847 will be available for those interested. The tour will begin at 8:30 after the talk.

Tonight's schedule:

7 PM: Plate Stacks exhibition
7:30 PM: Talk by Dr Louise Breuval and Dr Caroline Huang on Henrietta's legacy
8:30: Tour of the 1847 Great Refractor Telescope
9:30: End

Some photography will take place, but most photos will be of the guest speakers and low-lighting tour/rooftop activities. If you have any issues with photography, please reach out.

Parking on site on the night of the event is FREE. This includes parking lots specifically marked for observatory staff.

This event begins in the Phillips Auditorium, which is at the rear of the Harvard College Observatory complex near Madison Street and our large parking lot, 60 Garden Street, Cambridge. Please arrive 10 minutes in advance to ensure you have enough time to park and to get seated. 

We look forward to your presence at the event!

Original event summary:

Over a century ago, Henrietta Swan Leavitt revolutionized astronomy by discovering a powerful link between a star’s brightness and its pulsation period. Her groundbreaking work became the key to measuring vast cosmic distances and ultimately led to the discovery of the universe’s expansion. Now, with modern data, scientists have revisited her research—what new insights have they uncovered? How does her work continue to shape our understanding of the cosmos today?

Join us for an evening of discovery as ESA Research Fellow Louise Breuval (Space Telescope Science Institute) and NSF fellow Caroline Huang (CfA), present and explore Leavitt’s lasting impact, the latest findings, and how we still use her insights to map the universe. Then, step onto the roof of the Center for Astrophysics | Harvard & Smithsonian for telescope observations, where we’ll observe the cosmos just as Henrietta once did—weather permitting.

This event is sponsored by the Harvard College Observatory (HCO), part of the Center for Astrophysics | Harvard & Smithsonian (CfA). The CfA sponsors a variety of free programs for the public. Among these events are Public Observatory Nights. Observatory Nights feature two 20-minute non-technical lectures, and telescopic observing from the observatory roof if weather permits. The lectures are intended for high-school age and older audiences, but all are welcome. Admission is free, however, tickets are limited, and seating is first-come, first-served. Max 4 tickets per email address.

These events are held in Phillips Auditorium (at the rear of the CfA complex near Madison Street and the large parking lot), 60 Garden Street, Cambridge, about 1 mile west of Harvard Square. Parking lots marked for Observatory Staff are open to the public on event nights. Parking is FREE.

A few important points to keep in mind:

- This is a ticketed event, and all attendees must have a ticket for admission. Cancelled tickets will be readministered to individuals on the waitlist.

- Observations on the roof are weather-dependent. In case of unfavorable weather conditions, the talks will proceed as scheduled, but outdoor observations will be canceled. A tour of our historic Great Refractor will be offered if telescope observations are cancelled.

- Access to the roof is via stairs only. If you or a member of your party have any mobility limitations, please get in touch.

- Ensure you dress warmly for the occasion.

- High heels are not permitted on the roof.

- Some photography will take place. We generally avoid photographing faces, and focus more on the guest speakers and nighttime telescope activities. If you have any issues with photography, please reach out and let us know.

We look forward to your presence at the event! Please check the HCO outreach website for more details on our public engagement programs: https://hco.cfa.harvard.edu/ou...