Taking a reluctant star’s heartbeat
The pulse was taken with a telescope designed to find exoplanets
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Astronomers have finally heard the heartbeat of a mysterious class of variable star which previously defied having its pulse taken, it was announced in a recent paper.
Scientists used the precise stellar brightness measurements of NASA’s Transiting Exoplanet Survey Satellite (TESS) to look at the subtle vibrations of stars. They can use these fluctuations to reveal information about the stars’ inner layers, a technique known as asteroseismology. This study focused on 1,000 Delta Scuti stars – bright objects with masses between 1.5 and 2.5 times that of the Sun. However, their rapid spin distorts their shape and muddles the seismic pattern on the surface.
“To use a musical analogy, many stars pulsate along simple chords, but Delta Scuti stars are complex, with notes that seem to be jumbled,” says Tim Bedding from the University of Sydney, who led the study. “It was a mess, like listening to a cat walking on a piano.”
The precise TESS data allowed the researchers to cut through the noise and identify clear signals for 60 stars. www.nasa.gov/tess-transiting-exoplanetsurvey-satellite
To learn more about TESS turn to page 60
Date with an asteroid
NASA’s asteroid investigator, OSIRIS-REx, will take its first run at grabbing a sample from asteroid Bennu on 20 October
(as illustrated above), after a practice run in August. Once collected, both spacecraft and sample will depart for Earth in mid-2021, arriving back in September 2023.
UK funds space debris research
The UK Space Agency has provided £1 million of funding for organisations developing innovative ways to remove space junk from orbit. “Space debris is a global problem and this funding will enable UK companies to develop new methods to help tackle the issue,” says Alice Bunn, the agency’s International Director.
Observatories reopen
Telescopes on Mauna Kea in Hawaii were given permission to reopen on 9 May. Like many other observatories around the world, they were forced to close in response to the COVID-19 pandemic. Many have resumed observations, keeping staff to a minimum.