This presentation discusses serious astronomical research and will therefore be more complex than our typical ones. But most of the material will be understandable by non-technical viewers.

NOTE the change in accessing the presentation. See the bottom of the listing.

Title - Chasing Pluto: Occultation in the Outback

Since the discovery of Pluto's atmosphere using a stellar occultation in 1989, occultations have been an active area of research. Occultations occur when Pluto, or another body, passes in front of a star, blocking the incoming light. The resulting light curve can be used to probe the atmosphere and provide data rivaling that of a spacecraft.

Not only can an occultation indicate whether or not an atmosphere is present, it can also be used to determine characteristics such as atmospheric temperature, pressure, and composition. Occultation work is particularly timely now due to the 2015 New Horizons flyby and Pluto's orbital position. Data from New Horizons improved the accuracy of occultation predictions and provides a benchmark from which new measurements can be made.

As Pluto approaches the aphelion of its highly eccentric, nearly 250-year orbit, it is uncertain whether or not its atmosphere will completely freeze over; current work is focused on answering this question. On June 1, 2022, Pluto occulted a particularly bright (13th magnitude) star. Observations were made in Australia and promise new insight into Pluto's icy world.

The speaker is Abigail Colclasure from MIT

Details – Wednesday, October 19, from 7 – 8 PM. This will be a Zoom session only.

NOTE - The link will NOT appear in Front Porch Forum and the Lamoille County Star Gazers Facebook page as announced earlier. INSTEAD, please email the Lamoille County Star Gazers at lcvtsg@gmail.com to get the link.