Amateur astronomers detected abnormal behaviour in a star, but thye did not know that they were looking at an entirely unknown type.
The star is known as HD74423 is first of its kind as it is tear shaped and pulsates only on one side.
According to CNN, the astronomers first spotted the anomaly in data captured by NASA's latest planet-hunting space satellite TESS (Transiting Exoplanet Survey Satellite).
TESS is a space telescope for NASA's Explorers program, designed to search for exoplanets, planets outside our solar system.
"What first caught my attention was the fact it was a chemically peculiar star," Simon Murphy, study co-author and postdoctoral researcher from the Sydney Institute for Astronomy at the University of Sydney was quoted as saying.
"Stars like this are usually fairly rich with metals -- but this is metal poor, making it a rare type of hot star."
The star is about 1.7 times the mass of our sun. And they saw it pulsating -- but just on one side of the star, a heartbeat blinking at us from a great distance.
Stars pulsating is not a new phenomenon for scientists. Even the sun’s surface pulsates. But HD74423 is unique because every other star has fluctuations across its entire surface.
But why is it so? As space.com explains it: “That turns out to be because the star is a binary star, accompanied by a red dwarf star that is much smaller than our own sun. As the red dwarf whips around its larger companion every two days, its gravity pulls on HD74423. This tug distorts the surface of the larger star into a teardrop shape, also distorting the oscillations.”
According to the website, TESS was able to observe variations in the star's brightness during this distortion. The data was posted on the crowdsourcing website Planet Hunters TESS, where citizen scientists noticed that something different.