First Confirmed Object From Other Star System
Credit: Artist Impression NASA
by Zenaida Kotala
A cigar-shaped asteroid making its way through our solar system to an unknown destination is capturing the imagination of scientists around the globe.
This is this first confirmed object from another star system, which is what got University of Central Florida Associate Professor Yan Fernandez fired up and calling up friends to get telescope time at the Apache Point Observatory in New Mexico last month.
“On very, very short notice they were able to rework the telescope’s schedule — which is set months in advance — to get us 4 hours of time,” Fernandez said. “Time really was of the essence, since the asteroid was already on its way out of the Solar System — since it was discovered after it had already passed by the Sun.”
Fernandez and his collaborators published their observations this month in The Astrophysical Journal Letters.
“Up to now we’ve really only had our own asteroids to play with, and even though we know asteroids are out there orbiting other stars, we never really had a chance to check out to see if asteroids are made the same way pretty much everywhere or if there are specific things that happen in each planetary system that influence what kind of asteroids you wind up with,” Fernandez said. “In other words, are all asteroids like ours, or are ours unusual?”
He wasn’t alone in jumping at the chance to observe the asteroid. Several astronomers made frantic calls to get telescope time around the globe including at the European Space Agency’s Very Large Telescope in Chile. Researchers quickly measured the asteroid’s orbit, brightness and color. This was a rare opportunity to collect data to answer some fundamental questions.
The Pan-STARRS survey at the Institute for Astronomy in Hawaii discovered the strange object and named it `Oumuamua. Experts estimate the asteroid could have been coming through the Milky Way for hundreds of millions of years before its encounter with Earth’s solar system.
Fernandez is on a team with Hal Weaver and Casey Lisse from Johns Hopkins University and Bryce Bolin from the University of Washington. The team helped corroborate the shape of the object, its rotation properties, and its color, Fernandez said. The findings match up.
“The weirdest thing we found with our particular data is the apparent extreme elongation of the object,” he said. “We just don’t have that many asteroids that are that elongated in our own Solar System. We’ve got a real puzzle here, as to whether we’re just really lucky that we got a true oddball asteroid, or if this is a clue about some other process for creating and ejecting asteroids.”
As scientists collect data and answer some questions, a whole host of other questions arise. But that’s just part of the scientific process.
“It’s the real surprises that sometimes lead us to greater discoveries,” Fernandez said.