The newly discovered exoplanet TOI 849 b offers the unique opportunity to peer inside the interior of a planet and learn about its composition. It orbits around a star about 730 light years away, which is very similar to our sun.
The exposed core is the same size as Neptune in our solar system. The researchers assume that it is a gas giant that was either stripped of its gaseous atmosphere or that failed to fully form one in its early life due to special circumstances.
The study by the team led by Dr David Armstrong from the University of Warwick’s Department of Physics is published in the journal Nature. PD Dr. Christoph Mordasini from the University of Bern Physics Institute led the theoretical interpretation of the discovery.
A year that is a mere 18 hours
TOI 849 b is an extremely unusual planet in the so-called “Neptune Desert” – a term used by astronomers for a region close to stars where we rarely see planets of Neptune’s mass or larger. The lead author of the study, Dr. David Armstrong from the University of Warwick, says: “The planet is strangely close to its star, considering its mass. In other words, we don’t see planets with this mass at these short orbital periods.” TOI 849 b orbits so close to its host star that a year is a mere 18 hours and its surface temperature is around 1,500C.
Christoph Mordasini explains: “We have determined the planet’s mass and radius. TOI-849b is about 40 times heavier than the earth, but its radius is just 3.4 earth radii.” So the planet has a high density and therefore has to primarily consist of iron, rock and water, but only very little hydrogen and helium.
“Such a small amount of hydrogen and helium is really astonishing for such a massive planet. We would expect a planet this massive to have accreted large quantities of hydrogen and helium when it formed.”
David Armstrong adds: “The fact that we don’t see those gases lets us know TOI 849 b is an exposed planetary core.” This is the first time that an intact exposed core of a gas giant has been discovered around a star.
Bern’s expertise in demand worldwide
The University of Bern has been continuously developing the “Bern Model of Planet Formation and Evolution” since 2003. Christoph Mordasini says: “In our model, we combine insights into the manifold processes involved in the formation and evolution of planets.” Thanks to the world-renowned Bern model, discoveries such as those of the exoplanet TOI 849 b can be interpreted theoretically.
Based on the Bern model, two theories can be formulated which explain why TOI 849 b is not a typical gas giant but an exposed planetary core. “The first is that the exoplanet was once similar to Jupiter but lost nearly all of its outer gas through a variety of processes,” Christoph Mordasini says.
These could include tidal disruption, where the planet is ripped apart from orbiting too close to its star, or even a collision with another planet. Large-scale photoevaporation of the atmosphere could also play a role, but can’t account for all the gas that has been lost.
Alternatively, TOI 849 b could be a “failed” gas giant. “Once the core of the gas giant formed then something very unusual could have happened and it never formed a massive atmosphere as normally. This could have occurred if there was a gap in the disk of dust and gas that the planet formed from due to gravitational interaction with the planet, or if the disk ran out of material right at the very moment when gas accretion normally follows,” Mordasini adds.
David Armstrong says: “Our discovery proves that planets like this exist and we can track them down. We have the opportunity to look at the core of a planet in a way that we can’t do in our own solar system.”
How TOI 849 b was discovered and analyzed
TOI 849 b was found in a survey of stars by NASA’s Transiting Exoplanet Survey Satellite (TESS), using the transit method: the satellite measures the brightness of a star. A dip in brightness indicates that a planet has passed in front of them.
TOI 849 b was then analyzed using the HARPS instrument built under Swiss leadership, at the European Southern Observatory’s La Silla Observatory in Chile. This utilizes the Doppler effect to measure the mass of exoplanets by measuring their ‘wobble’ – small movements towards and away from us that register as tiny shifts in the star’s spectrum of light.
“Bern Model of Planet Formation and Evolution”
Statements can be made about how a planet was formed and how it has evolved using the “Bern Model of Planet Formation and Evolution”. The Bern model has been continuously developed at the University of Bern since 2003. Insights into the manifold processes involved in the formation and evolution of planets are integrated into the model.
These are, for example, submodels of accretion (growth of a planet’s core) or of how planets interact gravitationally and influence each other, and of processes in the protoplanetary disks in which planets are formed. The model is also used to create so-called population syntheses, which show which planets develop how frequently under certain conditions in a protoplanetary disk. The world-renowned Bern model is also used for the theoretical interpretation of discoveries such as that of the TOI 849 b exoplanet.
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Astronomers have made the first measurement of spin-orbit alignment for a distant ‘super-Jupiter’ planet, demonstrating a technique that could enable breakthroughs in the quest to understand how exoplanetary systems form and evolved.
An international team of scientists, led by Professor Stefan Kraus from the University of Exeter, has carried out the measurements for the exoplanet Beta Pictoris b – located 63 light years from Earth.
The planet, found in the Pictor constellation, has a mass of … read more
NAIROBI, Kenya (AP) — The body of Ugandan Olympic athlete Rebecca Cheptegei — who died after being set on fire by her partner in Kenya — was received Friday by family and anti-femicide crusaders, ahead of her burial a day later.
Cheptegei’s family met with dozens of activists Friday who had marched to the Moi Teaching and Referral Hospital’s morgue in the western city of Eldoret while chanting anti-femicide slogans.
She is the fourth female athlete to have been killed by her partner in Kenya in yet another case of gender-based violence in recent years.
Viola Cheptoo, the founder of Tirop Angels – an organization that was formed in honor of athlete Agnes Tirop, who was stabbed to death in 2021, said stakeholders need to ensure this is the last death of an athlete due to gender-based violence.
“We are here to say that enough is enough, we are tired of burying our sisters due to GBV,” she said.
It was a somber mood at the morgue as athletes and family members viewed Cheptegei’s body which sustained 80% of burns after she was doused with gasoline by her partner Dickson Ndiema. Ndiema sustained 30% burns on his body and later succumbed.
Ndiema and Cheptegei were said to have quarreled over a piece of land that the athlete bought in Kenya, according to a report filed by the local chief.
Cheptegei competed in the women’s marathon at the Paris Olympics less than a month before the attack. She finished in 44th place.
Cheptegei’s father, Joseph, said that the body will make a brief stop at their home in the Endebess area before proceeding to Bukwo in eastern Uganda for a night vigil and burial on Saturday.
“We are in the final part of giving my daughter the last respect,” a visibly distraught Joseph said.
He told reporters last week that Ndiema was stalking and threatening Cheptegei and the family had informed police.
Four in 10 women or an estimated 41% of dating or married Kenyan women have experienced physical or sexual violence perpetrated by their current or most recent partner, according to the Kenya Demographic and Health Survey 2022.
TEL AVIV, Israel (AP) — A rare Bronze-Era jar accidentally smashed by a 4-year-old visiting a museum was back on display Wednesday after restoration experts were able to carefully piece the artifact back together.
Last month, a family from northern Israel was visiting the museum when their youngest son tipped over the jar, which smashed into pieces.
Alex Geller, the boy’s father, said his son — the youngest of three — is exceptionally curious, and that the moment he heard the crash, “please let that not be my child” was the first thought that raced through his head.
The jar has been on display at the Hecht Museum in Haifa for 35 years. It was one of the only containers of its size and from that period still complete when it was discovered.
The Bronze Age jar is one of many artifacts exhibited out in the open, part of the Hecht Museum’s vision of letting visitors explore history without glass barriers, said Inbal Rivlin, the director of the museum, which is associated with Haifa University in northern Israel.
It was likely used to hold wine or oil, and dates back to between 2200 and 1500 B.C.
Rivlin and the museum decided to turn the moment, which captured international attention, into a teaching moment, inviting the Geller family back for a special visit and hands-on activity to illustrate the restoration process.
Rivlin added that the incident provided a welcome distraction from the ongoing war in Gaza. “Well, he’s just a kid. So I think that somehow it touches the heart of the people in Israel and around the world,“ said Rivlin.
Roee Shafir, a restoration expert at the museum, said the repairs would be fairly simple, as the pieces were from a single, complete jar. Archaeologists often face the more daunting task of sifting through piles of shards from multiple objects and trying to piece them together.
Experts used 3D technology, hi-resolution videos, and special glue to painstakingly reconstruct the large jar.
Less than two weeks after it broke, the jar went back on display at the museum. The gluing process left small hairline cracks, and a few pieces are missing, but the jar’s impressive size remains.
The only noticeable difference in the exhibit was a new sign reading “please don’t touch.”
VICTORIA – The British Columbia government is partnering with a bear welfare group to reduce the number of bears being euthanized in the province.
Nicholas Scapillati, executive director of Grizzly Bear Foundation, said Monday that it comes after months-long discussions with the province on how to protect bears, with the goal to give the animals a “better and second chance at life in the wild.”
Scapillati said what’s exciting about the project is that the government is open to working with outside experts and the public.
“So, they’ll be working through Indigenous knowledge and scientific understanding, bringing in the latest techniques and training expertise from leading experts,” he said in an interview.
B.C. government data show conservation officers destroyed 603 black bears and 23 grizzly bears in 2023, while 154 black bears were killed by officers in the first six months of this year.
Scapillati said the group will publish a report with recommendations by next spring, while an independent oversight committee will be set up to review all bear encounters with conservation officers to provide advice to the government.
Environment Minister George Heyman said in a statement that they are looking for new ways to ensure conservation officers “have the trust of the communities they serve,” and the panel will make recommendations to enhance officer training and improve policies.
Lesley Fox, with the wildlife protection group The Fur-Bearers, said they’ve been calling for such a committee for decades.
“This move demonstrates the government is listening,” said Fox. “I suspect, because of the impending election, their listening skills are potentially a little sharper than they normally are.”
Fox said the partnership came from “a place of long frustration” as provincial conservation officers kill more than 500 black bears every year on average, and the public is “no longer tolerating this kind of approach.”
“I think that the conservation officer service and the B.C. government are aware they need to change, and certainly the public has been asking for it,” said Fox.
Fox said there’s a lot of optimism about the new partnership, but, as with any government, there will likely be a lot of red tape to get through.
“I think speed is going to be important, whether or not the committee has the ability to make change and make change relatively quickly without having to study an issue to death, ” said Fox.
This report by The Canadian Press was first published Sept. 9, 2024.
