Australian Scientists Discover New 'Pulsating' Star

By Sarah Basford on at

Australian scientists have discovered a new type of star that 'pulsates' on one side. The star is believed to have existed in theory for decades but the new findings prove it's a reality after all.

research paper published in nature.com reveals the star, called HD74423 and is situated around 1,500 light years from Earth, pulsates on just the one side.

"It has long been suspected that tidal forces in close binary stars could modify the orientation of the pulsation axis of the constituent stars," the study reads. "Such stars have been searched for, but until now never detected."

Sydney Institute for Astronomy's Dr Simon Murphy, who co-authored the paper, said the star caught his attention due to the fact it is chemically peculiar.

"Stars like this are usually fairly rich with metals — but this is metal poor, making it a rare type of hot star," Dr Murphy said in a University of Sydney article.

Pulsating in stars can cause variations in brightness — as if stars are 'breathing'. These changes are due to the area and temperature of the star's surface layers. Before the discovery of HD74423, which is 1.7 times the mass of the Sun, stars had only been observed pulsating on both sides. So, what makes it different?

The researchers found the anomaly is due to its close proximity to a red dwarf — a dim, small star, which actually distorts its gravitational pull due to its short orbital time. Its led to the pulsating star forming more of a tear drop shape due to the red dwarf's orbit.

Interestingly, it was first noticed by amateur sleuths pouring over publicly-available data provided by NASA's TESS satellite. This goes to show, the internet's community of amateur astronomers can truly do anything they set their minds to. [Via University of Sydney]

Featured image: Getty


Gizmodo Australia is gobbling up the news in a different timezone, so check them out if you need another Giz fix.


Tags: