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This Star Has Exploded Annually For Millions of Years

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star in andromeda galaxy explodes

GK Persei, seen above, is a prime example of a nova remnant. Unlike supernovae, which blow stars apart from within, novae explosions occur on the surfaces of accreting white dwarfs. Though the previous record for largest nova remnant is about 3.5 light-years wide, researchers recently discovered M31N 2008-12a, a nova remnant that spans over 400 light-years.
(Credit: X-ray: NASA/CXC/RIKEN/D.Takei et al; Optical: NASA/STScI; Radio: NRAO/VLA)

Astronomers have discovered a star in the Andromeda galaxy that has been regularly erupting for the past million years, leaving behind one of the biggest shells of ejected material scientists have ever seen.

The new research, which was published last month in the journal Nature, not only marks the first discovery of such a super-remnant in another galaxy, it also paves the way for detecting a potentially massive population of repeatedly exploding stars, called recurrent novae, which may help shed light on how the universe has changed over time.

Swing Your Partner

The star responsible for this expansive remnant, which stretches over 400 light-years across, is actually from one of the most diminutive types of star: a white dwarf. These stellar corpses are left behind after a smallish star dies and blows off its outer layers, leaving behind only its dense core.

But in the case of this remnant, catchily named M31N 2008-12a, the culprit is not your ordinary white dwarf. This tiny star has a dance partner.

As the white dwarf and its nearby companion star orbit each other, the white dwarf rapidly siphons hydrogen from its buddy. As this unspent hydrogen fuels reaches the surface, it’s heated and compressed thanks to the white dwarf’s intense gravitational pull. Eventually, the hydrogen reaches a breaking point and spontaneously fuses to create helium, resulting in a powerful surface explosion we call a nova.

This burst of fusion causes the white dwarf to temporarily brighten up to a millionfold as it ejects material outward at about 3 percent the speed of light. In the case of M31N 2008-12a, over time, these repeated explosions have created an extensive and ever-expanding cocoon of gas and dust around the white dwarf.

According to the study, “Larger than almost all known remnant of even supernova explosions, the existence of this shell demonstrates that the nova M31N 2008-12a has erupted with high frequency for millions of years.”

It Keeps Going, and Going…

The massive size of the remnant is not its only claim to fame. Indeed, M31N 2008-12a also now holds the title of most frequently recurring nova, as it erupts at least once a year. “When we first discovered that M31N 2008-12a erupted every year, we were very surprised,” said co-author Allen Shafter of San Diego State University in a press release. This is because most recurrent novae only explode about once a decade.

But despite the fact that the white dwarf has spent the past million years or so exploding annually, researchers don’t think it will last forever. Once the white dwarf surpasses the Chandrasekhar limit — which is about 1.4 times the mass of the sun — it will irreparably blow itself apart as a supernova or collapse down into a neutron star.

According to theory, white dwarfs that are approaching the Chandrasekhar limit should undergo frequent novae explosions, resulting in gigantic remnants. And because that’s exactly what astronomers see happening around M31N 2008-12a, they think this star may be priming up for a supernova explosion itself. However, you and I likely will not be around to witness it.

“In less than 40,000 years,” the study says, “the underlying composition of the white dwarf will be revealed incontrovertibly when either a type Ia supernova or an accretion-induced collapse of the white dwarf to a neutron star is observed.”

If the researchers are able to find other examples of huge remnants around different novae, they think they may learn a bit about type Ia supernovae. Because type Ia supernovae have very predictable brightnesses (which is why they’re called standard candles), by studying them, researchers can pin down cosmic distances with extreme accuracy. Ultimately, this helps them better understand how the universe grows and evolves over time.

“They are, in effect, the measuring rods that allow us to map the visible universe,” said Shafter. “Despite their importance, we don’t fully understand where they come from.”

So for now, Shafter and his colleagues are working hard to determine whether super-remnants like M31N 2008-12a are the exception, or the rule. And if they’re as common as some think, then the next step becomes improving our ability to spot them.

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Ecology

Yukon and Northern BC First Nations tackle climate change using Indigenous knowledge and science

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YUKON, June 18, 2021 /CNW/ – The Government of Canada is working together in partnership with Indigenous and Northern communities in finding solutions to adapt to the impacts of climate change in the North.

Today, Minister of Northern Affairs, Daniel Vandal, along with Parliamentary Secretary to the Minister of Economic Development and Official Languages (Canadian Northern Economic Development Agency), Larry Bagnell, highlighted progress on three unique, Indigenous-led projects that are helping communities in Yukon and Northern British Columbia adapt to the challenges posed by climate change.

The Minister and Parliamentary Secretary met virtually with Carcross/Tagish First Nation (C/TFN) to learn about their community-led climate change monitoring program. C/TFN has partnered with Tsay Keh Dene Nation (TKDN) and Chu Cho Environmental of Prince George, British Columbia, to build a community-led monitoring project that examines environmental data and Indigenous knowledge to create a holistic picture of how the climate is changing across C/TFN and TKDN traditional territories. The project combines tracking of current and historical climate trends with knowledge shared by Elders while also providing opportunities for youth mentorship and climate change awareness.

The Taku River Tlingit First Nation (TRTFN) is also leading a unique project to assess the impacts of climate change within their traditional territory. Climate change is causing many of the culturally significant ice patches to melt, exposing organic artifacts to oxygen and leading to rapid deterioration. The TRTFN ice patch mapping project will involve performing archaeological assessments to prevent the degradation of artifacts. Research will be guided by traditional knowledge, Elders and oral histories, when available, and heavily involve community, Elders, youth and Knowledge Keepers.

The Pelly Crossing Selkirk Development Corporation is leading the Selkirk Wind Resource Assessment project through the installation of a Sonic Detection and Ranging (SODAR) system. The initiative includes a feasibility study leading up to the construction of a renewable energy facility, including wind, solar and battery energy storage. Expanding clean energy within the region will have direct benefits for communities, including reduced reliance on diesel, job creation and revenue generation for Selkirk First Nation. 

These projects are delivering important environmental, social and economic benefits that lead to healthier, more sustainable and resilient communities across Yukon and Northern British Columbia. They also build community clean energy capacity and help to avoid the impacts of climate change.

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Ecology

Atlantic Provinces Ready For Aquaculture Growth

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Aquaculture is an important economic driver for rural, coastal and Indigenous communities, and Atlantic Canada is well positioned to increase aquaculture production as global demand for sustainably sourced seafood grows.

That is why the ministers responsible for aquaculture in the Atlantic provinces have agreed to the ongoing development and management of their industries based on common principles. A new memorandum of understanding has been signed by the four ministers, which extends the previous agreement signed in 2008.

“In a time when food security is especially important, it is good to see our aquaculture industry has grown steadily and is poised for continued growth in 2021 based on environmentally responsible, science-based policies and practices,” said Keith Colwell, Minister of Fisheries and Aquaculture for Nova Scotia. “Our Atlantic partnership continues to help the industry grow sustainably.”

Cooperation between the provinces and the aquaculture industry has led to improvements in pest management, environmentally sustainable aquaculture methods, aquatic animal health and policies to support the shared use of marine and freshwater resources. It also aims to align regulation and policy between the provinces to make the regulatory requirements easier to understand by industry and the public.

Each province has a comprehensive and robust legislative and regulatory framework to ensure environmental sustainability, economic prosperity and public accountability. The provinces update their legislation and regulations regularly. Nova Scotia revamped its regulatory framework in 2015; New Brunswick received Royal Assent for a new Aquaculture Act in 2019 and is working on the supporting regulations; Newfoundland and Labrador completely revised its aquaculture policy in 2019; and Prince Edward Island has recently drafted a new Aquaculture Act.

The ministers have agreed to continue to use science-based evidence for management decisions, thereby increasing public and investor confidence in the Atlantic Canadian aquaculture industry.

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Ecology

COMING SOON: A Healthy Environment and a Healthy Economy 2.0

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We all want the same thing: a clean and responsible energy future for our children and future generations while continuing to enjoy a high standard of living.

On December 11, 2020, the Prime Minister announced a new climate plan which he claimed will help achieve Canada’s economic and environmental goals.

The proposed plan by Environment and Climate Change Canada (ECCC) entitled “A Healthy Environment and a Healthy Economy” will have an initial investment of $15 billion of taxpayer’s money. It is built on 5 pillars of action:

  1) Making the Places Canadians Live and Gather More Affordable by Cutting Energy Waste

2) Making Clean, Affordable Transportation and Power Available in Every Community

3) Continuing to Ensure Pollution isn’t Free and Households Get More Money Back

4) Building Canada’s Clean Industrial Advantage

5) Embracing the Power of Nature to Support Healthier Families and More Resilient Communities  

In my paper, “A Healthy Environment and a Healthy Economy 2.0” I will objectively critique each pillar in the government’s new climate plan and provide alternative solutions to the same issues.

  This is an alternative plan that supports workers, protects lower income earners and creates economic growth while respecting the environment and focusing on the dignity of work.

  This plan abandons virtue-signaling projects and relies on Canadian ingenuity to build our economy and restore Canada’s role of responsible leadership in the world.

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