NASA | GSFC | TESS | 2020 May 13
Astronomers have detected elusive pulsation patterns in dozens of young, rapidly rotating stars thanks to data from NASA’s Transiting Exoplanet Survey Satellite (TESS). The discovery will revolutionize scientists’ ability to study details like the ages, sizes and compositions of these stars — all members of a class named for the prototype, the bright star Delta Scuti.Delta Scuti Star Pulsations ~ Credit: NASA/GSFC/SVS
“Delta Scuti stars clearly pulsate in interesting ways, but the patterns of those pulsations have so far defied understanding,” said Tim Bedding, a professor of astronomy at the University of Sydney. “To use a musical analogy, many stars pulsate along simple chords, but Delta Scuti stars are complex, with notes that seem to be jumbled. TESS has shown us that’s not true for all of them.” ...
But scientists have had trouble interpreting Delta Scuti pulsations. These stars generally rotate once or twice a day, at least a dozen times faster than the Sun. The rapid rotation flattens the stars at their poles and jumbles the pulsation patterns, making them more complicated and difficult to decipher. ...
Pulsations in the well-behaved Delta Scuti group fall into two major categories, both caused by energy being stored and released in the star. Some occur as the whole star expands and contracts symmetrically. Others occur as opposite hemispheres alternatively expand and contract. Bedding’s team inferred the alterations by studying each star’s fluctuations in brightness. ...
Astronomers Decipher Rhythm Among Young Stars
Institute for Astronomy | University of Hawaii | 2020 May 13
Astronomers Find Regular Rhythms Among Pulsating Stars
University of Central Lancashire | University of Sydney | 2020 May 13
Very Regular High-Frequency Pulsation Modes in Young Intermediate-Mass Stars ~ Timothy Bedding et al