Colloquia

2019 HotSci at STScI

Wed 24 Jul 2019
Location:

Space Telescope Science Institute (STScI)
3700 San Martin Drive
Baltimore, MD 21218

Time:

2:45 PM - 4:00 PM

Contact Information:

Have questions? Please contact Martha Devaud.

Description:

Featuring Jeff Cummings on Constraining Stellar Rotation, Internal Mixing, and AGB Stars Using The Initial-Final Mass Relation and Carol Christian on Tactile 3D Astronomy.

Notes:

All talks are held on Wednesdays in the STScI John N. Bahcall Auditorium at 3:00 p.m. preceded by refreshments at 2:45 p.m.

Name: Jeff Cummings 
Title: Constraining Stellar Rotation, Internal Mixing, and AGB Stars Using The Initial-Final Mass Relation
Abstract: Analysis of white dwarfs, the remnants of a majority of stars, provide significant insight on the evolutionary processes that occur during a star's life. Because of their simple, typically pure hydrogen atmospheres, spectroscopic observations of white dwarfs allow straightforward determination of their masses, cooling ages, and atmospheric parameters. Observed in the contexts of known stellar populations, they can then be connected to the mass and characteristics of a star that would produce such a white dwarf. This initial-final mass relation now provides a powerful connection between stars from 0.85 to 7.5 Msun and the white dwarfs they form. As our understanding of this relation improves, in lower-mass stars (< 3 Msun) it is continuing to inform us about their poorly understood mass-loss rates, dredge-up processes, core-mass evolution, and their connection to carbon stars. In higher-mass stars (> 3 Msun) it is also beginning to directly constrain the effects of convective-core overshoot and rotation on core evolution, two processes that are difficult to model and up until now have been poorly constrained by observations.

Name: Carol Christian 
Title: Tactile 3D Astronomy 
Abstract: We are using a unique process developed at STScI to transform Hubble images into tactile touchable 3D representations. These prints represent the spatial extent of the objects as seen in the sky, as well as the intensity of the radiation emitted as a surrogate for the amount of mass present in the object. Obviously this is not a strict representation of structure and physics, but neither are color images of astronomical objects. Our approach, different than others producing 3D prints, is to use HST data to represent the main features of the objects (stars, gas, dust, spiral structure, filamentary structures) and to add specific, unique, textures to the 3D prints so that the features can be identified by touch. The goal is to enable visually impaired students, but also others, to experience and learn about astronomy in a way that does not rely on vision. Our main scientific data is drawn from studies of star clusters and galaxies.