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Star will collapse, explode – Skywatching – Castanet.net

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In science and technology, we are now fairly used to the idea of achieving things today that were unthinkable even a few years ago.

This applies to astronomy, too. One of these is our new ability to make useful images of other stars. Stars other than the sun are no longer inaccessible points of light. We are finding that other stars can be very different from our local, yellow dwarf star. A good example of this is revealed by images taken by the Atacama Large Millimetre Array (ALMA) of the red supergiant Antares, a star in the constellation of Scorpius, which we can see this time of the year low in the southern sky.

ALMA is a radio telescope consisting of an array of 66 dish antennas, which function together as a radio camera. This is an international project in which Canada is a partner. It uses radio wavelengths of a few millimetres (your local FM stations use wavelengths in the region of three metres). At these wavelengths the instrument acts as a very sensitive thermal imager, seeing through the dust clouds that block visible light and infrared. Millimetre wavelengths are strongly absorbed by our atmosphere, especially the water vapour in it, so ALMA is located on one the highest, driest places in the world, the Atacama Plateau in Chile.

Antares is a red supergiant star. It has about 12 times the mass of the sun. The brightness of a star increases enormously as the mass increases. A star with 12 times the mass of the sun will radiate energy at about 5,000 times the rate our sun radiates energy. This means that despite its having more fuel available, it will have a shorter life than the sun. Our star will have a lifetime in the region of 10 billion years. Antares will run out of fuel after a lifetime of about 25 million years. If it has any planets, there is not much chance of life developing on any of them. Antares is now close to the end of its life, and is running out of fuel.

When stars get old, they swell enormously into red giant stars. The sun will do this. With its higher mass, Antares has swollen into a red supergiant star. When we start to run out of something, we generally become more frugal in the way we use it. Paradoxically, stars do the reverse. They burn through their remaining fuel even faster. Antares is now shining about 80,000 times the brightness of the sun. To sustain this, it is totally annihilating 320 billion tonnes of its material every second.   

Antares has expanded to about 700 times the diameter of the sun. Even with 12 times the solar mass, this means the star is about as close to being a very hot vacuum as one can get. Its gravitational hold on its outer layers is weak, and they are flowing off into space as a supersized solar wind. This is where ALMA comes in; it has imaged the outer layers of Antares and revealed how they have become hugely swollen. For example, immediately above the yellow, shining “surface” of our sun, there is a hot layer known as the chromosphere, maybe 2,000 km thick. Antares has pushed its chromosphere out to a thickness of around 500 million kilometres. It is losing material into space at a horrendous rate. This cannot last. When the fuel runs out, the outward pressure will vanish and the star will collapse and then explode. This is likely to happen in the next few thousand years. For a few months, it will outshine everything in the sky other than the sun and moon.

Antares means “Rival of Ares,” where Ares is the Greek name for the god of war. His Roman name is Mars.  Both bodies appear as red lights in the sky. However, since stars twinkle and planets don’t, it is easy to see which is which. Some time in the next few thousand years, Mars will no longer have any competition. It might worth keeping a weather eye on the southern sky.

  • Before dawn, Jupiter and Saturn are close together in the south.
  • Mars lies low in the southeast.
  • Venus lies low in the sunrise glow.
  • The moon will be full on the 4th. 

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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.

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