Left: A normal star in a binary system gravitationally pulls in matter from an aging companion star that has swelled to a bloated red giant that has expanded to a few hundred times its original size. Right: After a couple hundred million years, the red giant star has burned out and collapsed to the white dwarf that shines intensely in ultraviolet wavelengths. The companion star has bulked up on the hydrogen siphoned off of the red giant star to become much hotter, brighter, and bluer than it was previously.

( NASA, ESA, and A. Feild (STScI))

New observations from the Hubble Space Telescope now give scientists a better look at solving the mystery behind seemingly ageless stars.

Thanks to astronomers Robert Mathieu and Natalie Gosnell, we now have a better look at how stars weigh on each other. We know that half of all stars are in binary systems—pairs that orbit each other so closely that gravitational interaction has an effect on their lifespan and growth. However, with the help of the Hubble telescope and their team, they have , also known as a blue straggler, says a University of Wisconsin-Madison article.

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Blue stragglers are described as in comparison to other stars with which they formed, seeming hotter, making them younger and bluer, National Geographic explains.

What astronomers expect is that these stragglers remain so youthful and blue because they steal hydrogen fuel from their partner star.

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"Until now there was no concrete observational proof, only suggestive results," Gosnell, an astronomer at the University of Texas, Austin, said in a McDonald Observatory statement. "It's the first time we can place limits ."

The larger star in the binary . As the companion gets hotter and brighter, thefirst star is siphoned from until it's dwindled down to a dense, small white dwarf. For nearly two-thirds of the blue stragglers observed, this study confirms the mass transfer process, says Space.com.

"For the evolution of single stars like our sun, by and large, we got it right, from birth to death,” Mathieu later said. “Now we're starting to do the same thing for the one-quarter of stars that are close-orbiting binaries. This work allows us to talk not about points of light, but about the evolution of galaxies, including our own Milky Way. That's a big deal, and getting it right is an even bigger deal."

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NASA’s Solar Dynamics Observatory captured this close-up image of an outburst on the sun's surface, between Nov. 3-5, 2015. Though the sun’s extreme ultraviolet light is invisible to our eyes, the wavelength is colorized here in red. (NASA/SDO)