|Andrea Dupree is senior scientist at the Center for Astrophysics and Director of the Solar, Stellar, Planetary Sciences Division. She has followed Betelgeuse since the 80’s…first with the International Ultraviolet Explorer, then by taking the first image of a star other than the Sun…that is, Betelgeuse, from the Hubble Space Telescope, which revealed large hot convective cells on its surface. Most recently, she formed a group called the MOB (Months of Betelgeuse), which is watching Betelgeuse from the ground and space to understand processes of mass loss and the circumstellar environment. And then Betelgeuse had a ‘Great Dimming Event’ that she will talk about in her keynote:|
"The Mysterious Great Dimming of Betelgeuse"
|The bright cool supergiant Betelgeuse became historically faint in February 2020. Various explanations have been offered for its unusual behavior – including conjectures this foreshadows an imminent supernova event. AAVSO photometry; direct imaging; spatially resolved spectroscopy; polarization measures; and infrared, optical, and ultraviolet spectra help us to unravel what is happening to the star. When Betelgeuse is close to the sun in May–July, photometry continues using the spacecraft STEREO that trails the Earth in its orbit. These measurements allow this historic event to be followed from its origin in the stellar surface, through the extended atmosphere, and into the circumstellar medium.|
Sara Seager is a professor of three academic disciplines: Planetary Science, Physics, and Aerospace Engineering at the Massachusetts Institute of Technology.
Please stay tuned for Sara's full bio and keynote abstract.
David Latham is a Harvard Astronomy Department lecturer and senior astronomer at the Smithsonian Astrophysical Observatory (SAO) of the Harvard-Smithsonian Center for Astrophysics.
Please stay tuned for David's full bio.
"Spectroscopy of Eclipsing Binaries and Brown Dwarfs Identified by TESS"
|The pixels in the TESS cameras correspond to 21 arc seconds on the sky, and shallow transit-like events are often due to contamination by deep events from eclipsing binaries as much as an arc-minute away. Seeing-limited photometry using CCD cameras on small telescopes is an important tool for identifying false positives due to nearby eclipsing binaries. Even when follow-up photometry shows that the dips are on the target star, it may be a false positive due to eclipses by a small star or a brown dwarf, which can have roughly the same size as a giant planet. Reconnaissance spectroscopy with the ability to measure Doppler velocities at the level of about 1 km/s is an effective way for exoplanet enthusiasts to weed out the TOIs that are due to stellar and brown-dwarf companions. But, some people think that small stars and brown dwarfs are interesting in their own right. In this talk, I will show what it takes to derive masses, radii, and even ages for such companions.|
More details on speakers coming soon!