With the help of the old technique that was used to discover the very first exoplanet in 1995, astronomers have discovered a planet orbiting two stars at the same time.
This rarely observed phenomenon, called circumbinary planets, has never before been detected using this technique.
“Whereas people were previously able to find planets around single stars using radial velocities pretty easily, this technique was not being successfully used to search for binaries,” David Martin, co-author of the study and NASA Sagan Fellow in astronomy at The Ohio State University, said in a press release.
The newly discovered planet is a gas-giant that is 65 times more massive than Earth. It orbits two stars along with another, smaller exoplanet — a term which refers to planets orbiting stars outside of our own — which had previously been detected in 2020. Prior to this discovery of a second planet in this system, only one other multi-planet circumbinary system has ever been found: Keplar-47, which is believed to have three orbiting exoplanets.
The image of Luke Skywalker watching two suns setting on his home planet of Tatooine in “Star Wars: Episode IV – A New Hope” is one of the most iconic images of science fiction, but for a long time, the idea of a planet orbiting two stars was believed to be nothing more than that — science fiction.
However, NASA’s Keplar project, which was a spacecraft launched in 2009 with the goal of detecting planets, helped scientists understand that binary star systems and circumbinary planets were much more common than previously thought.
Half of the stars in the sky are single stars, meaning that if they have planets, those planets only orbit around them. But the other half of the stars are in systems with each other, with some consisting of two stars moving in an established pattern together, others consisting of three or four. Not all of these multi-star systems have a planet or planets orbiting them, but how common they are means that there are likely many more planets orbiting two or more stars than we are currently aware of.
“When a planet orbits two stars, it can be a bit more complicated to find because both of its stars are also moving through space,” Martin said. “So how we can detect these stars’ exoplanets, and the way in which they are formed, are all quite different.”
Currently, there are only 12 binary systems known to host circumbinary planets. Astronomers behind this new discovery, described Monday in the peer-reviewed journal Nature Astronomy, are hoping that this marks progress in how we search for a detect exoplanets in these unique systems.
The vast majority of the exoplanets that astronomers have discovered in the universe thus far have been discovered using the transit method.
This method involves tracking the light from stars over a large period of time to measure if the star’s brightness dims at any point. A dip in brightness that follows a specific pattern suggests that a planet is passing in front of the star on a regular basis as it orbits it.
When astronomers first started looking for exoplanets, however, they found the first exoplanet, called Dimidium, by using the radial velocity method.
This method relies on watching the tiny shifts in a star’s position in the sky as it is pulled by the gravity of an orbiting planet. This gravitational interaction makes a star wobble ever so slightly, a movement that can be detected by looking at the colour signature of the star’s light. A star that is red-shifted is farther away, while a blue shift indicates that it is closer, as longer light wavelengths appear redder.
If this wobble is happening on a regular basis, it almost certainly means there is a planet pulling on the star as it orbits it.
In the past, this method has been best at detecting large exoplanets that are quite close to their stars, as well as establishing the mass of already detected exoplanets.
What it hasn’t been good at is detecting planets in binary or multi-star systems, since in these systems, the stars are not only being affected by a planet’s gravity, but the gravity of the other star or stars in the system.
This new discovery of a binary system with two circumbinary planets is a step forward for the radial-velocity survey called BEBOP — which stands for “binaries escorted by orbiting planets.”
The system is officially called TOI-1338/BEBOP-1, showing that it is the first entry in the BEBOP catalogue of circumbinary planets that have been found using the radial velocity method.
Although the transit method is very reliable in detecting planets, it is also limited in its scope, as it requires a planet to pass between its star on a plane that lines up with Earth’s view of that star, meaning that we could be missing planets that are orbiting on a tilted orbit. The transit method also favours planets with a shorter orbital period, as it’s easier to establish a pattern of orbit if a planet doesn’t take years to complete one orbit.
BEBOP-1c, which refers specifically to the larger of the two planets orbiting in this system, hasn’t transited in front of the star yet, and it’s unknown when it will. The smaller planet hasn’t been picked up by radial velocity data, but researchers were able to infer its presence using existing data on it.
The BEBOP program is believed to be particularly helpful in detecting circumbinary planets in binary systems where one star is much brighter than the other.
“If we are to unravel the mysteries of circumbinary Tatooine-like exo-atmospheres, the BEBOP-1 system may provide a new hope,” authors wrote in the study.
The inner planet is also sparking interest because it is eligible for atmospheric study by the James Webb Space Telescope, a development which could help look for whether life is possible on this planet. If NASA studies the inner planet further, it would be the first planet orbiting two stars to have its atmosphere studied.
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.
