Two Powerful Observatories Join Forces to Discover 8 Celestial Objects Hidden by Brighter Companions
By combining the capabilities of the GRAVITY instrument from the European Southern Observatory (ESO) mounted on the Very Large Telescope in Chile and the Gaia sky-mapping satellite from the European Space Agency (ESA), scientists have identified 8 of the most difficult-to-observe celestial objects in the universe.
These include 5 brown dwarfs and 3 other faint stars that were previously concealed by bright light.
Eight celestial objects hidden by companion stars have been identified – (AI Image: Anh Thư).
This may sound counterintuitive, but in a star system, planets and other objects located relatively far from the bright star are often identified first.
In many cases, a highly active star will overshadow the surrounding objects with its dazzling brightness, causing telescopes to become “blinded.”
In this recent study, a group of scientists from ESO and ESA examined hundreds of thousands of stars suspected of having companions, using initial data recorded by Gaia.
Then, the unique sensitive and sharp “eye” of GRAVITY helped filter out the overwhelming brilliance surrounding the suspected stars and identify 8 companions to 8 bright stars, 7 of which had never been known before.
According to SciTech Daily, 3 of these are very small and faint stars.
The remaining five are brown dwarfs, a type of celestial object that hovers between being a star and a planet: too large to be considered a planet and possessing some stellar characteristics, yet too small to sustain nuclear fusion in their cores like stars.
Therefore, brown dwarfs can be regarded as failed stars or high-end planets.
One of the brown dwarfs discovered in this study orbits its companion star at a distance comparable to that between Earth and the Sun.
This marks the first time a brown dwarf has been directly captured at such a close distance to its companion star.
GRAVITY also measured the contrast between the companion star and the main star across a range of wavelengths in the infrared spectrum.
Combined with mass estimates, this allowed the team to assess their ages. Surprisingly, 2 of the brown dwarfs turned out to be dimmer than expected based on their size and age.
A possible explanation for this could be that these failed stars have an even smaller companion. However, it remains unclear what type of celestial object that might be.
The power of the duo Gaia – GRAVITY demonstrated in this study brings another hope: the search for tiny planets near their parent stars that are hidden in the glare.
Such planets include rocky bodies like our Earth. Thus, this new pathway could lead humanity toward a world with life.
