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Globular clusters with hundreds of stars spotted in space

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In summer, the constellation Hercules, named after the hero in Greek myths, is high in the sky.

The constellation looks like a broad-shouldered, headless man doing a crazy dance. To find it, follow the curve of the Dipper’s handle to the bright, orange star, Arcturus. Almost overhead find Vega, a bright, bluish-white star. Hercules lies about halfway between those stars.

If the night is dark and clear, just below Hercules’ left shoulder (assuming he is facing us), there is a faint, fuzzy dot. Binoculars will show it well and a nice big telescope will show it spectacularly. The object is a ball of stars, so crowded in the central regions the stars blur together in a continuous glow. Then, as we look further out toward the edges, the stars become more and more sparse.

The object is a globular cluster, about 150 light years in diameter, containing several hundred thousand stars. This globular cluster, known as M13, is one of at least 160 orbiting around the outside of our galaxy.

Almost all other galaxies seem to have their own collections of these compact clusters of stars.

Very few stars lie within 10 light years of us, and in our skies, only a few of them look really bright. In the core of a globular cluster the stars are a fraction of a light year apart.

People on planets in these crowded neighbourhoods would need no streetlights. However, so far no such planets have been found. Maybe they are rarer than elsewhere in our galaxy because there is little material available to make them.

Actually, there is another reason why, as yet, we may not have detected any planets in globular clusters. Because the stars are so close together, any planet orbiting a star in a globular cluster will have lots of nearby stars tugging at it. This continual tweaking can grossly change a planet’s orbit, or even send it off into space all by itself.

Since the way we search for planets is to look for the minute dimmings as they pass in front of their respective stars, this massive orbital interference may make detecting planets unlikely, if they are there to be found.

The stars in globular clusters are old, with little material around to form new ones. It is relatively easy to see clouds of cosmic gas and dust, but how can we determine the age of a star?

Actually, this is not very difficult. Our universe started off with two elements, mainly hydrogen with some helium mixed in. Stars formed from this mixture, and obtained energy through nuclear fusion, turning hydrogen into all the other elements. When these stars exploded at the end of their lives, these by-products got added to the surrounding clouds. When new stars form from clouds containing these by-product elements, we can detect them.

There is no circulation between the core, where energy production is going on, and the surface. Therefore, anything in the surface material in addition to hydrogen and helium was inherited from earlier generations of stars. Stars formed back in the youth of the universe contain little if anything other than hydrogen and helium in their surface layers. Younger stars, like the sun, contain a good mixture of heavier elements.

Globular clusters are among the oldest objects in their galaxies and maybe in the universe. During their long lives they went through a number of episodes of star formation, but that all stopped long ago. There seems to be no new star formation going on now.

These mysterious cosmic fossils look spectacular through large telescopes, and are very common; almost every galaxy has some. They are favourite targets for amateur astronomers’ telescopes.

We still trying to work out how they formed, and when that happened. However, we believe they formed when the universe was quite young.

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Venus shines very brightly in the west after sunset, with Mars, higher, in the southwest.

Saturn lies very low in the dawn glow.

The Moon will reach its first quarter on April 27.

Ken Tapping is an astronomer with the National Research Council’s Dominion Radio Astrophysical Observatory near Penticton, B.C.

This article is written by or on behalf of an outsourced columnist and does not necessarily reflect the views of Castanet.

 

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The body of a Ugandan Olympic athlete who was set on fire by her partner is received by family

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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.

Kenya’s high rates of violence against women have prompted marches by ordinary citizens in towns and cities this year.

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.

The Canadian Press. All rights reserved.

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The ancient jar smashed by a 4-year-old is back on display at an Israeli museum after repair

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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.”

The Canadian Press. All rights reserved.

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B.C. sets up a panel on bear deaths, will review conservation officer training

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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.

The Canadian Press. All rights reserved.

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