Just months after the discovery of FarOut, the farthest object of the solar system, the same team of astronomers has detected the weaknesses – still unconfirmed – of the glimmers of an even more distant object. Nicknamed FarFarOut, the extreme dwarf planet is 13 billion kilometers away – a distance so far, it takes nearly 20 hours to sunlight to reach it.
Sometimes it takes a day of snow to promote an incredible scientific discovery.
Astronomer Scott Sheppard of the Carnegie Institution for Science was scheduled to give a lecture last week in Washington DC on the ongoing research of a hypothetical Planet Nine, reports Science Magazine. But when bad weather forced him to postpone the event, Sheppard decided to review the astronomical data collected by his team in January.
And this is when he spotted it: an object located at 140 astronomical units (AU) of the Earth, where 1 AU corresponds to the average distance between the Earth and the Sun, about 93 million miles. The newly discovered object – probably an extreme dwarf planet – has been attributed the FarFarOut placeholder name, potentially replacing FarOut as the farthest known object of the solar system.
In December 2018, Sheppard, along with colleagues Chadwick Trujillo of Northern Arizona University and David Tholen of the University of Hawaii, spotted FarOut or 2018 VG18, an object of the Kuiper belt located at 120 AU from the Earth. . Earlier in the year, the same team discovered Goblin, or 2015 TG38, another extreme dwarf planet located at 80 AU. All objects, including FarFarOut, were detected by this team with the 8-meter Subaru Japanese telescope located atop Mauna Kea in Hawaii. Other distant objects previously known include Eris at 96 AU and Pluto at 34 AU.
This trio of astronomers has traveled the Kuiper Belt for years and is conducting the largest and most extensive survey ever attempted in the region. This research could lead to the discovery of the hypothetical Planet Nine, sometimes called Planet X, which would exist because of the abnormal orientation of certain objects in the confines of the solar system. Planet X has not yet been found, but with every discovery of other Kuiper Belt objects, astronomers are getting closer and closer to proving or refuting its existence.
"It's exciting to look at the sky without anyone ever picturing it as deeply as we are," Sheppard told Gizmodo. "To paraphrase Forrest Gump, every image we take is like a box of chocolates – you never know what you're going to find."
The ability to detect objects at such extreme distances depends on the size of the object, he said, and we should be able to see large objects even if they are very far away. FarFarOut has a length of about 400 km, which is close to our current ability to detect objects at around 140 AU. Indeed, in the image showing FarFarOut, the object appears as a weak point of light. Had she been smaller, FarFarOut would probably have escaped detection, Sheppard explained. That said, if objects larger than FarFarOut exist beyond 140 AU, we should be able to detect them.
"We have covered about 25% of the sky so far in our investigation. So there should be some bigger objects than FarFarOut that we should be able to detect, "said Sheppard.
For the moment, the existence of this so-called extreme dwarf planet has not been proved conclusively. Sheppard needs to see him again to confirm he is there and confirm his orbit.
"For now, we've been watching FarFarOut only for a 24-hour timebase," he said. "These discovery observations show that the object is around 140 AU, but it could also be between 130 and 150 AU. We do not yet know its orbit because we did not make the required follow-up observations. "
But if a snow storm can motivate this discovery, the weather would be a major obstacle.
"I am currently in Chile with the Magellan telescope and hope that the weather will be nice in the next few days so that we can observe this interesting object," he said.[Science Magazine]