Scialog: Collaborative Teams - 2015
Astronomy, Penn State
Technologies and Techniques for High Precision Photometric and Spectroscopic Stellar TDA
A team of astronomers is attempting to make a major technological leap to improve the quality of observations of distant stars from ground-based telescopes.
Leslie Hebb, of Hobart and William Smith Colleges; Suvrath Mahadevan, of Penn State; and John Wisniewski, of the University of Oklahoma, are developing new and improved techniques for high-precision photometric and infrared spectroscopic observations.
Photometry is concerned with measuring the flux or intensity of a star’s light and other electromagnetic radiation; infrared (IR) spectroscopy focuses on wavelengths longer than those of visible light to determine a star’s chemical composition and movement through space. Hebb, Mahadevan and Wisnewiski are working in the emerging field of time-domain astrophysics, which is concerned with tracking changes in celestial objects over time.
Based on the serendipitous discovery at a Scottish observatory that foggy nights often yielded the most precise photometric observations, the researchers are developing a light-shaping diffusion filter to mimic the effects of fog. It will spread the pinpoint starlight obtained by a well-focused telescope over many more pixels of the instrument’s focal plane. The method has the advantage of high-precision targeting and increased sensitivity for the photometric sensor.
The team will attempt to design and install such a diffuser on the versatile Astrophysical Research Consortium (ARC) 3.5-meter Telescope at the Apache Point Observatory located in the Sacramento Mountains of south-central New Mexico.
In addition the team’s will perform high-resolution IR spectroscopy, work that involves connecting a fiber-optic datalink to the ARC Telescope to allow it to share a high-resolution spectrograph currently in use by another Apache Point instrument now dedicated to the Sloan Digital Sky Surveys.
Specifically, Hebb, Mahadevan and Wisniewski hope to use these improvements to study the magnetic fields of massive stars that seem to lack the usual outer envelope of hot gasses; they also plan to study a wide variety of smaller stars to determine their temperatures, metal content and movements through space.