space.com Tiny rogue planet is the smallest free-floating exoplanet candidate yet

[UltraMega]

Quote

The researchers pulled a very interesting signal out of the OGLE observations — an event called OGLE-2016-BLG-1928, which at 42 minutes long is the shortest microlensing event ever detected. The team further characterized the event using data collected by the Korea Microlensing Telescope Network, which operates telescopes in Chile, Australia and South Africa.

 

"When we first spotted this event, it was clear that it must have been caused by an extremely tiny object," co-author Radoslaw Poleski, of the Astronomical Observatory of the University of Warsaw, said in the same statement.

 

The team's calculations suggest that the lensing body has a mass between that of Mars and Earth, and is probably closer in heft to the Red Planet than to our own world. And the OGLE-2016-BLG-1928 candidate is likely zooming through deep space all by its lonesome.

 

"If the lens were orbiting a star, we would detect its presence in the light curve of the event," Poleski said. "We can rule out the planet having a star within about 8 astronomical units." 

 

One astronomical unit, or AU, is the average distance from Earth to the sun — about 93 million miles (150 million kilometers). In our own solar system, an object at 8 AU would circle the sun between Jupiter and Saturn — a strange place for a small, rocky planet to exist.

 

The new study was published online today (Oct. 29) in Astrophysical Journal Letters. You can read a preprint of it for free at arXiv.org.

Source: https://www.space.com/smallest-rogue-planet-discovery

 

It's widely believed that a planet sized object collided with the earth at some point billions of years ago and created a debris field that eventually coalesced into the moon. Finding an exo-planet in our solar system supports the moon collision theory. Pretty interesting stuff.

 

Note: micro-lensing is the same as gravitational lensing which is the visible curvature of light caused by an object with its own gravity. 

[Mistio]

I was always fascinated by Astrophysics and Astronomy. 
Sadly I wasn't a math whizz to follow this into depth. 

[UltraMega]

On 10/30/2020 at 4:49 AM, Mistio said:

I was always fascinated by Astrophysics and Astronomy. 
Sadly I wasn't a math whizz to follow this into depth. 

I'm in the same boat.