General Meeting – March 2020

6:30 pm – Introductory Presentation

Title:  The Astronomical League and TAAA’s Astronomy Fundamentals Class

Speakers:  Doug Smith and JD Metzger

TAAA member Doug Smith talks about The Astronomical League, and TAAA member JD Metzger talks about  TAAA’s Astronomy Fundamentals Class.

7:30 pm – Main Presentation

Title:  Using Light Echoes as Time Machines

Speaker:  Jennifer Andrews is an observational astronomer interested in massive stars and the violent explosions that signal the end of their lives.  She has been at Steward Observatory for the past few years, and spends a lot of her time observing supernovae and other transients with telescopes in Southern Arizona.  Jennifer received her PhD at Louisiana State University, and prior to moving to Tucson she worked as a postdoc at the University of Massachusetts

The great eruption of the massive star Eta Carinae in the mid-1800s was a spectacular astronomical event, when it likely ejected a mass of material 10 – 20 times that of the Sun, and was visible to the naked eye. Until recently the only observations of that eruption were historical visual estimates of Eta Carinae’s brightness and color. Thanks to our evolving ability to use light echoes (LEs) we can now re-examine the event. As some light from Eta Carinae’s eruption traveled directly toward us and was observed in the 1800s, light directed away from us was scattered off dust, and we are finally observing it today as a light echo. Over the past decade we have been obtaining imaging and spectroscopy of these echoes with telescopes in the Southern Hemisphere, enabling us to reconstruct Eta Carinae’s physical state prior to and during the great eruption.  Jennifer will discuss these observations and what they reveal about one of the most enigmatic massive stars in the Milky Way