The top of the planet’s atmosphere is heated to a blazing 2,500 degrees Celsius, hot enough to boil some metals. Credit: NASA, ESA, and G. Bacon (STSci)
An international team of researchers led by the National Centre of Competence in Research PlanetS of the University of Bern and the University of Geneva studied the atmosphere of the ultra-hot exoplanet WASP-121b. In it, they found a number of gaseous metals. The results are a next step in the search for potentially habitable worlds.
WASP-121b is an exoplanet located 850 light years from Earth, orbiting its star in less than two days — a process that takes Earth a year to complete. WASP-121b is very close to its star — about 40 times closer than Earth to the Sun. This close proximity is also the main reason for its immensely high temperature of around 2,500 to 3,000 degrees Celsius. This makes it an ideal object of study to learn more about ultra-hot worlds.
Researchers led by Jens Hoeijmakers, first author of the study and postdoctoral research fellow at the National Centre of Competence in Research PlanetS at the Universities of Bern and Geneva, examined data that had been collected by the high-resolution HARPS spectrograph. They were able to show that a total of at least seven gaseous metals occur in the atmosphere of WASP-121b. The results were recently published in the journal Astronomy & Astrophysics.
Unexpectedly much going on in the atmosphere of exoplanet WASP-121b
WASP-121b has been extensively studied since its discovery. “The earlier studies showed that there is a lot going on in its atmosphere,” explains Jens Hoeijmakers. And this despite the fact that astronomers had assumed that ultra-hot planets have rather simple atmospheres because not many complex chemical compounds can form in such blistering heat. So how did WASP-121b come to have this unexpected complexity?
“Previous studies tried to explain these complex observations with theories that did not seem plausible to me,” says Hoeijmakers. The studies had suspected that molecules containing the relatively rare metal vanadium were the main cause of the complex atmosphere in WASP-121b. According to Hoeijmakers, however, this would only make sense if a more common metal, titanium, were missing in the atmosphere. So Hoeijmakers and his colleagues set out to find another explanation. “But it turned out that they were right,” admits Hoeijmakers unequivocally. “To my surprise, we actually found strong signatures of vanadium in the observations.” At the same time, however, titanium was missing. This in turn confirmed Hoeijmakers’ assumption.
Vaporized metals
But the team made other, unexpected discoveries. In addition to vanadium, they newly discovered six other metals in the atmosphere of WASP-121b: Iron, chromium, calcium, sodium, magnesium and nickel. “All metals evaporated as a result of the high temperatures prevailing on WASP-121b,” explains Hoeijmakers, “thus ensuring that the air on the exoplanet consists of evaporated metals, among other things”.
A new era in exoplanet research
Such detailed results allow researchers to draw conclusions about the chemical processes that take place on such planets, for example. This is a crucial skill for the not too distant future, when larger, more sensitive telescopes and spectrographs will be developed. These will allow astronomers to study the properties of smaller, cooler rocky planets similar to Earth. “With the same techniques we use today, instead of just detecting signatures of gaseous iron or vanadium, we will be able to focus on biosignatures, signs of life such as the signatures of water, oxygen and methane,” says Hoeijmakers.
The extensive knowledge about the atmosphere of WASP- 121b not only confirms the ultra-hot character of the exoplanet, but also underlines the fact that this field of research is entering a new era, as Hoeijmakers puts it: “After years of cataloguing what is out there, we are now no longer just taking measurements,” explains the researcher, “but we are really beginning to understand what the data from the instruments show us. How planets resemble and differ from each other. In the same way, perhaps, that Charles Darwin began to develop the theory of evolution after characterizing countless species of animals, we are beginning to understand more about how these exoplanets were formed and how they work”.
Reference: “Hot Exoplanet Atmospheres Resolved with Transit Spectroscopy (HEARTS) — IV. A spectral inventory of atoms and molecules in the high-resolution transmission spectrum of WASP-121 b” by H. J. Hoeijmakers, J. V. Seidel, L. Pino, D. Kitzmann, J. P. Sindel, D. Ehrenreich, A. V. Oza, V. Bourrier, R. Allart, A. Gebek, C. Lovis, S. N. Yurchenko, N. Astudillo-Defru, D. Bayliss, H. Cegla, B. Lavie, M. Lendl, C. Melo, F. Murgas, V. Nascimbeni, F. Pepe, D. Ségransan, S. Udry, A. Wyttenbach and K. Heng, 18 September 2020, . DOI: 10.1051/0004-6361/202038365
Exoplanetary research with the HARPS spectrograph
The HARPS spectrograph is capable of detecting the faint light coming from distant planets with astonishing precision. Jens Hoeijmakers explains: “The atoms in the exoplanet’s atmosphere each absorb part of the star’s light. Each atom thus has a virtually unique fingerprint of the colours it absorbs”. These fingerprints can be measured with a sensitive spectrograph such as HARPS and the chemical composition of the exoplanet’s atmosphere can be derived from them, even if they are many light years away.
The HARPS spectrograph was developed under the leadership of the Geneva Observatory by a consortium that also included the Observatoire de Haute-Provence, the Physics Institute of the University of Bern and the Service d’Aéronomie, Paris.
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.
