Article Introduction: Astronomers speculate that Beiluoshimen B is not a planet, which may be an expanding dust cloud produced by a large-scale collision
Is North Fall Gate a planet that never existed? Astronomers have been debating the stars near the planet.
Is North Gate B a planet that never existed? Astronomers have been debating the stars near the planet.
Now, on the basis of previously unpublished observations and computer simulations, the University of Arizona and Dr. Andras. Gaspar and George. Rick made the case in the National Academy of Sciences newspaper: There wasn't a single planet there, only the wreckage of a massive asteroid collision.
The artist's concept art shows the violent asteroid collision that could form the North Fall Gate B that we see.
Crack the North Fall Division Gate B
Since 1993, the North-Fallen Gate galaxy has been the target of exoplanet research, in part because it is very young, only existing for 440 million years, but more because it radiates more infrared light than is expected to be a single planet. Over time, high-resolution images showed a warm dust circle similar to Sauron's Eye surrounding the North Fallen Star. This thin circle suggests that the giant "Guardian" star will affect the structure of the North Gate over time.
But when UC Berkeley Paul. When Kalas and his colleagues captured Beiluoshimen b in 2005, the results were not one of the suspicious "shepherds." Instead, the images scanned by their Hubble Space Telescope showed a small amount of visible light 115 astronomical units away from the North Gate. If it orbits the Sun, it should be in the Kuiper Belt far away.
A small amount of light movement proves that it is not a background star. But in subsequent infrared observations, it did not appear, probably because of its small mass. In fact, some infrared observations have limited its mass to a small dot, and astronomers have begun to wonder if the visible light comes from a planet.
"Nordsman b is undoubtedly one of the most provocative discoveries discovered by Hubble," Karas said, "of course, Nordsmen b is also one of the most difficult discoveries in the history of exoplanet science." (To supplement the history of Callas, a personal explanation was made based on the study of the North Fall Division b.) ）
Build on old ideas and explore further with new data.
Writers soon realized that ordinary planets would scatter the light of their host star, but could not explain everything they saw. Therefore, they put forward two points. First, the object could be a small world still hidden in dust (or maybe it might even arise from a satellite system). ）。
Or, the object may not be a planet, but just a cloud of expanding dust that was created at the moment of the recent violent asteroid collision.
Gaspar and Rick changed the latter scenario based on their previously unpublished Hubble images from 2013 and 2014. Between 2004 and 2014, Hubble observations were only seven years of data. During a decades-long tracking of the object, Gaspar and Rick found that its trail moved out of the galaxy, while also lengthening slightly. At the same time, in 2014, they also found that the object gradually disappeared out of the observable range.
On the left is a Hubble telescope image of the North Gate Galaxy; the star forms a masking zone so that the remaining galaxies can be seen without glare. The right side of the chart simulates a cloud of dust that is constantly expanding and declining during an asteroid collision.
"The observed features do not match the planetary model of the object," Gaspar said. So he and Rick simulated a spectacular collision between a giant asteroids more than five hundred meters in diameter. Larger debris mainly follows their orbits, and radiation pressure from the planet blows away smaller dust particles, giving the object an extended appearance.
In general, the assumption of the reasons for the orbit of the North Fall gate b explained by the expanding dust cloud is more reasonable than the idea of a dust-shrouded planet, but the difference between the two theories is small.
A lucky event?
"Andras. Gaspar has an impressive model of the phenomenon of star-child collisions," Callas said. But the tricky question is this: The explanation requires a little bit of lucky coincidence.
"The constituent matter in a 440 million-year-old planetary system is basically formed," Gasper explains. "For example, the collisions we assume, collisions with a radius of more than 100 kilometers like this, are actually very rare in young galaxies."
But if such an event is so rare, why would astronomers have the opportunity to capture it? "Being able to produce a star-sub-collision of The North Fall gate b, probably every 100,000 years, would produce a cloud of dust that can only be observed for a decade," Callas noted. In fact, Gaspar and Rick speculate that the first observations were made only 39 days after the collision. "When I discovered The North Gate with the Hubble Space Telescope, was I really the luckiest astronomer in the world?" Kalas asked.
Gaspar admits: "This was one of the reasons why this model was not necessarily promoted early in the discovery of the North Fall Gate B. However, he argues, the idea of an inflated dust cloud explains all the observations, "sometimes you're really lucky enough to observe a rare event," he adds.
"This model looks plausible and is a reasonable attempt to explain the observations," Scott said. Kenyon (Harvard & Smithsonian, Center for Astrophysics) says he's provided a small piece of advice in the past, though in the past he insisted that the new model would require a little luck.
Some events may make violent planetary collisions more common. For example, if there is a giant planet attracting a huge circle, perhaps they will produce a slightly different material from that galaxy; the Kuiper Belt is more likely to form. Moreover, without more data, it is difficult to present accurately.
We need more data
"The hypothesis of the expanding dust cloud is only based on the results of hubble observations over seven years," Karas said, "and I have applied for the hubble telescope's use time from 2020 to 2021 to re-observe to verify the hypothesis of the expanding dust cloud." ”
The controversial North Fall Gate B depicted by old artists shows a small world surrounded by dust. This proposed one may insist that the planet exists, but is shrouded in dust.
"I certainly don't mind if our model turns out to be wrong," Gaspar said. For him, although the substance has weakened beyond being observed by Hubble, that doesn't mean we shouldn't try, and even if the images don't show that the substance still provides useful information.
At the same time, he will use the James Webb Space Telescope launched in 2021 to observe the galaxy's infrared radiation in greater depth. "Science is always evolving," he notes, "and new observations and data are being collected along with it." ”
BY: MONICA YOUNG
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