In 1967, astronomer viewed a rotating and highly magnetized neutron star (aka. pulsar) for the first time. Since that time, these “cosmic lighthouses” – so named because of the strobing effect they create – have been a source of ongoing study and fascination. Scientists have even proposed using them as navigation beacons because of the way their electromagnetic pulses are perfectly timed and can be used to gauge distances.
In all cases, these powerful stars were found to have rhythmic pulsations that were visible from all sides. But a recent discovery by an international team has confirmed that there are neutron stars that can pulse from only one side. This pulsar, part of a system known as HD 74423, is located about 1,500 light-years from Earth and is the first of its kind to be found.
For decades, astronomers have theorized about the existence of pulsars whose oscillations are visible from only one side. But it was not until recently, thanks to citizen scientists who were examining data from NASA’s exoplanet-hunting Transiting Exoplanet Survey Satellite (TESS), that a candidate was found.
Shortly thereafter, the citizen scientists contacted Prof. Saul Rappaport, a researcher with the MIT Kavli Institute and the contact person of the TESS research effort. Before long, he was joined by an international team of astronomers who were also busy studying this pulsar, which was revealed to be part of a binary system.
Known as HD 74423, and located 1,500 light-years from Earth, this system consists of a white dwarf that is roughly 1.7 times the mass of the Sun and an M-type red dwarf companion. These two stars orbit each other with a period of just 1.6 days, which made it easy to detect them making transits (where they passed in front of each other relative to the observer).
Prof. Gerald Handler, a researcher at the Nicolaus Copernicus Astronomical Center was the lead author of the paper. As he explained in a recent CAMK-PAN press release, “The exquisite data from the TESS satellite meant that we could observe variations in brightness due to both the gravitational distortion of the star as well as the pulsations”.
Artist’s illustration of a rotating neutron star, the remnants of a supernova explosion. Credit: NASA, Caltech-JPL
To their surprise, the team observed that the strength of the pulsations depended on the angle to which the star was observed, as well as the corresponding orientation of its red dwarf star companion. In the end, all of the tiny fluctuations in brightness observed by the team appeared only when the same hemisphere of the star was pointed towards them.
This is how the astronomers were able to conclude with certainty that the pulsations were happening on only one side of this pulsar. The strength of these pulsations, they noted, also varied with an almost two-day period, matching the orbital period of the stars. From this, the team theorized that the tight orbit of this binary pair results in them exerting a considerable gravitational pull on each other.
This effect would disrupt the surfaces of both stars and cause them to become elongated and tear-drop shaped, which would also have the effect of focusing the pulsar’s electromagnetic pulses to one side. As Paulina Sowicka, a Ph.D. student at CAMK PAN and co-author of the study, said:
“As the binary stars orbit each other we see different parts of the pulsating star. Sometimes we see the side that points towards the companion star, and sometimes we see the outer face.”
As early as the 1940s, astronomers have predicted that there could be a class of stars where pulsations are affected by a close companion. Also, the idea that tidal forces can cause the pulsation axis of a star to move has been theorized by astronomers for over 30 years. Thanks to this study and all those who made it possible, there is finally observational proof of these phenomena (which was lacking until now).
Professor Don Kurtz, a researcher at the University of Central Lancashire (UK) and co-author of the study, was quite excited by the find, which he has spent the better part of his career looking for. “We’ve known theoretically that stars like this should exist since the 1980s,” he said. “I’ve been looking for a star like this for nearly 40 years and now we have finally found one.”
Also exciting is the fact that this discovery is not at all likely to be the last of its kind. In fact, as Prof. Rappaport was sure to add, “Beyond its pulsations, there doesn’t seem to be anything special about this system, so we expect to find many more hidden in the TESS data!”
Last, but not least, this find is exciting because of the way it brought together a cutting-edge science mission, citizen scientists, and professional researchers to make a major discovery. It is a testament to the current age of astronomy and space exploration, which takes advantage of data-sharing and public participation like ever before.
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.
