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Is Betelgeuse About To Explode? – Forbes

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Rogelio Bernal Andreo

When you take a look at the stars in the night sky, they generally appear the same regardless of time. Only a small number of stars ever appear to change on human timescales, as most stars burn through their fuel very stably, with almost no variation in their continuous brightness. The few stars that do appear to change are either intrinsically variable, members of multi-star systems, or go through an enormous evolutionary change.

When very massive stars get close to the end of their lives, they start varying by tremendous amounts, and do so with significant irregularity. At a critical moment, most of these stars will run out of the nuclear fuel holding up their cores against collapse, and the resulting implosion leads to a runaway cataclysm: a core-collapse supernova. Could Betelgeuse, whose variability intensified in a novel way over the last few days, be about to explode? Here’s what astronomers know so far.

A. Dupree (CfA), R. Gilliland (STScI), NASA

The last time our species witnessed a supernova from within our own galaxy with the naked human eye, the year was 1604. A new point of light in the sky suddenly appeared, brightened, and briefly outshone every single star before slowly fading away. This wasn’t the first such event, as prior supernovae had illuminated Earth’s skies like this in 1572, 1054, and 1006, among others.

But all of those supernovae occurred from stars that were thousands of light-years away, with Kepler’s 1604 explosion being traced back to a stellar remnant located some 20,000 light-years across the Milky Way. Of all the stars we see in the night sky, one bright member stands out as the most fascinating possibility as our galaxy’s next supernova: Betelgeuse, one of our sky’s 10 brightest stars, located a mere 640 light-years away.

ESO/L. Calçada

Betelgeuse, best known as the bright red “shoulder” star in the constellation of Orion, is one of the most remarkable objects in all of astronomy. It is a red supergiant star: red because of its low surface temperatures, supergiant because its radius is so enormous that — if it were to replace the Sun in our Solar System — it would engulf the orbits of Mercury, Venus, Earth, Mars, the asteroid belt, and possibly even Jupiter! In terms of physical size, it’s approximately 900 times the radius, and 700 million times the volume, of our Sun.

Betelgeuse is so large and so close that it was the first star beyond our Sun to ever be resolved as more than a point source. But perhaps its most fascinating property is that Betelgeuse is a pulsating, variable star, meaning that its diameter and brightness both change with time.

NRAO/AUI and J. Lim, C. Carilli, S.M. White, A.J. Beasley, and R.G. Marson

At approximately 20 times the mass of our Sun, there’s little doubt that Betelgeuse is headed on it was to becoming a supernova. Betelgeuse was likely formed in the great Orion molecular cloud complex very recently on cosmic scales: within the last 10 million years. It has already finished burning through all the hydrogen fuel in its core, and has gone onto the next element, helium, which it fuses into carbon.

Perhaps ironically, the core of Betelgeuse is now much smaller than when it was fusing hydrogen, as it contracted and heated up tremendously in order to begin fusing helium. The outer layers, with this increased radiation pressure, expanded and cooled tremendously. At a surface temperature of only 3500 K, barely half the temperature of our Sun’s photosphere, only 13% of Betelgeuse’s energy output is detectable to human eyes. If we could see the entire electromagnetic spectrum from our perspective, Betelgeuse would outshine every star in the Universe except our Sun.

NASA / WISE

We aren’t sure whether Betelgeuse is exclusively fusing helium in its core, or whether the interior has contracted even further and is now fusing carbon. While the helium fusion phase lasts for timescales of ~100,000 years, carbon fusion lasts for merely hundreds. Unfortunately, the only signature that would give us a surefire view of what processes are occurring in the core — neutrino emissions — are too faint to be seen from 640 light-years away.

All we can observe, when it comes to Betelgeuse at the present, is what’s occurring in its outermost layers. When we look there, what we see is remarkable: it’s constantly losing mass, pulsing, having its outermost layers expelled, and changing over time in both its apparent brightness and redness.

ESO/P. Kervella

Recently, in just the past few weeks, its brightness has dropped tremendously, knocking it out of the top 10 brightest stars for the first time in many years. This dimming has led many to suspect that a supernova may be imminent, but this is extremely unlikely. The story is simple, straightforward, but not known by most people, with the exception of professional astronomers.

The key takeaway is this: what’s occurring in the outer layers of a supergiant star is largely unrelated to what processes are occurring in the inner core of a supergiant star. When you examine variable stars in general, you might think that the pulsing/variability that you see is because some process that’s changing in the core is propagating to the surface, but that’s not usually the case. Instead, there are huge convective cells in the outer layers of the star, and changes there are more than capable of causing this dimming.

AAVSO / Lautaro Vergara

In fact, if you look beyond the previous decade and instead go back to the past century, you’ll find that Betelgeuse has been this dim many, many times in the past. If you look beyond the photosphere of the star itself, you’ll find that there are enormous radio emissions that reveal the presence of expelled gas out beyond where the orbit of Neptune is around the Sun.

Similar dimming events have occurred before, reducing the brightness of Betelgeuse below even what it currently is at. But to see a dimming event occur this rapidly and this severely really hasn’t been seen before over the past century at all. It’s unlikely to be a signature of an imminent supernova, but we have to remember that since the advent of modern astronomy, we’ve never seen a star up close in the lead-up to a supernova. Whether there’s a detonation about to happen or not, something fascinating is truly occurring.

Bernd Freytag with Susanne Höfner & Sofie Liljegren

What’s not up for debate is how truly remarkable the processes at play are here. On our Sun alone, the sized of the convective cells that we find are larger than the continent of North America, with sunspots frequently exceeding the size of Earth. On the surface of a red supergiant — thousands of times larger than our Sun — there might only be a handful of convective cells altogether, causing it to look like, according to astronomer Emily Levesque, a “wacky, giant, boiling amoeba-star,” as simulated above.

Our actual astronomical maps of Betelgeuse cannot yet attain that kind of resolution, but can still reveal the following properties of Betelgeuse:

  • its irregular shape,
  • its uneven, non-uniform temperature,
  • localized hot spots,
  • and even faint plumes of illuminated ejecta near the photosphere itself.

ALMA (ESO/NAOJ/NRAO)/E. O’Gorman/P. Kervella

The opportunity to study a red supergiant up close, one that’s about to go supernova relatively soon (at least, on astronomical timescales), has never occurred like this before. At only 640 light-years distant, Betelgeuse could have gone supernova at any time since the 14th century and that signal would not yet have arrived here on Earth.

When that supernova does occur, however, we’re in for a real treat. The runaway fusion reaction that occurs in the final few instants of the star’s life will generate neutrinos that should lead to millions of detectable events here our terrestrial neutrino detectors. The star will brighten to the point where it will rival or possibly even exceed the brightness of the full Moon, casting brilliant shadows at night and being clearly visible during the day for more than a year.

Wikimedia Commons user HeNRyKus / Celestia

Unfortunately, though, the key question of exactly when Betelgeuse is going to go supernova is one that we’re not any closer to having an answer to. Until we can measure the processes occurring in the star’s core, which would require a neutrino telescope far more powerful than all the neutrino observatories on Earth combined, we cannot know which elements are being fused inside of it.

Right now, our best models are consistent with helium-burning rather than any of the heavier elements, indicating that we have at least hundreds of years — and possibly hundreds of thousands — until the inevitable supernova finally detonates. If you haven’t checked out the constellation of Orion recently, though, take a good look and notice how much dimmer red Betelgeuse is than blue Rigel, a severe departure from its past decade of appearances. A supernova may not be imminent, but is sure is fascinating to watch and hope!

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VIDEO: Why Nova Scotia health officials are testing for COVID-19 in a community that's largely been spared from the virus – SaltWire Network

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Over the weekend of Jan. 16-17, people in the Bridgewater, N.S. area were offered rapid COVID-19 testing for the first time since the province introduced the process last fall.

In the video above, Dr. John Ross speaks to SaltWire’s Sheldon MacLeod about why Nova Scotia health officials are looking for the virus in a community that has been mostly free of infections, even during the height of the outbreaks in the province.

This weekend, people in the Bridgewater area were offered Rapid COVID-19 testing for the first time since the province introduced the process last fall. Dr. John Ross explains why are they looking for the virus in a community that has been mostly free of infections, even during the height of the outbreaks in Nova Scotia. – Sheldon MacLeod
- Sheldon MacLeod
– Sheldon MacLeod
- Sheldon MacLeod
– Sheldon MacLeod

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Edmundston hospital under pressure; province reports 20 new cases – Yahoo News Canada

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The Canadian Press

The latest numbers on COVID-19 in Canada for Sunday, Jan. 24, 2021

The latest numbers of confirmed COVID-19 cases in Canada as of 4:00 a.m. ET on Sunday Jan. 24, 2021. There are 737,407 confirmed cases in Canada. _ Canada: 737,407 confirmed cases (65,750 active, 652,829 resolved, 18,828 deaths).*The total case count includes 13 confirmed cases among repatriated travellers. There were 5,957 new cases Saturday from 101,130 completed tests, for a positivity rate of 5.9 per cent. The rate of active cases is 174.92 per 100,000 people. Over the past seven days, there have been a total of 41,703 new cases. The seven-day rolling average of new cases is 5,958. There were 206 new reported deaths Saturday. Over the past seven days there have been a total of 1,100 new reported deaths. The seven-day rolling average of new reported deaths is 157. The seven-day rolling average of the death rate is 0.42 per 100,000 people. The overall death rate is 50.09 per 100,000 people. There have been 16,996,450 tests completed. _ Newfoundland and Labrador: 398 confirmed cases (10 active, 384 resolved, four deaths). There was one new case Saturday from 146 completed tests, for a positivity rate of 0.68 per cent. The rate of active cases is 1.92 per 100,000 people. Over the past seven days, there has been three new case. The seven-day rolling average of new cases is zero. There have been no deaths reported over the past week. The overall death rate is 0.77 per 100,000 people. There have been 77,472 tests completed. _ Prince Edward Island: 110 confirmed cases (seven active, 103 resolved, zero deaths). There were zero new cases Saturday from 418 completed tests, for a positivity rate of 0.0 per cent. The rate of active cases is 4.46 per 100,000 people. Over the past seven days, there have been a total of six new cases. The seven-day rolling average of new cases is one. There have been no deaths reported over the past week. The overall death rate is zero per 100,000 people. There have been 88,407 tests completed. _ Nova Scotia: 1,570 confirmed cases (22 active, 1,483 resolved, 65 deaths). There were five new cases Saturday from 721 completed tests, for a positivity rate of 0.69 per cent. The rate of active cases is 2.26 per 100,000 people. Over the past seven days, there have been a total of 20 new cases. The seven-day rolling average of new cases is three. There have been no deaths reported over the past week. The overall death rate is 6.69 per 100,000 people. There have been 200,424 tests completed. _ New Brunswick: 1,087 confirmed cases (332 active, 742 resolved, 13 deaths). There were 30 new cases Saturday from 1,031 completed tests, for a positivity rate of 2.9 per cent. The rate of active cases is 42.74 per 100,000 people. Over the past seven days, there have been a total of 203 new cases. The seven-day rolling average of new cases is 29. There were zero new reported deaths Saturday. Over the past seven days there has been one new reported death. The seven-day rolling average of new reported deaths is zero. The seven-day rolling average of the death rate is 0.02 per 100,000 people. The overall death rate is 1.67 per 100,000 people. There have been 133,199 tests completed. _ Quebec: 250,491 confirmed cases (17,763 active, 223,367 resolved, 9,361 deaths). There were 1,631 new cases Saturday from 8,857 completed tests, for a positivity rate of 18 per cent. The rate of active cases is 209.35 per 100,000 people. Over the past seven days, there have been a total of 11,746 new cases. The seven-day rolling average of new cases is 1,678. There were 88 new reported deaths Saturday. Over the past seven days there have been a total of 423 new reported deaths. The seven-day rolling average of new reported deaths is 60. The seven-day rolling average of the death rate is 0.71 per 100,000 people. The overall death rate is 110.32 per 100,000 people. There have been 2,695,925 tests completed. _ Ontario: 250,226 confirmed cases (25,263 active, 219,262 resolved, 5,701 deaths). There were 2,662 new cases Saturday from 69,403 completed tests, for a positivity rate of 3.8 per cent. The rate of active cases is 173.43 per 100,000 people. Over the past seven days, there have been a total of 18,918 new cases. The seven-day rolling average of new cases is 2,703. There were 87 new reported deaths Saturday. Over the past seven days there have been a total of 412 new reported deaths. The seven-day rolling average of new reported deaths is 59. The seven-day rolling average of the death rate is 0.4 per 100,000 people. The overall death rate is 39.14 per 100,000 people. There have been 8,895,862 tests completed. _ Manitoba: 28,260 confirmed cases (3,261 active, 24,204 resolved, 795 deaths). There were 171 new cases Saturday from 1,998 completed tests, for a positivity rate of 8.6 per cent. The rate of active cases is 238.12 per 100,000 people. Over the past seven days, there have been a total of 1,118 new cases. The seven-day rolling average of new cases is 160. There were two new reported deaths Saturday. Over the past seven days there have been a total of 36 new reported deaths. The seven-day rolling average of new reported deaths is five. The seven-day rolling average of the death rate is 0.38 per 100,000 people. The overall death rate is 58.05 per 100,000 people. There have been 448,638 tests completed. _ Saskatchewan: 21,643 confirmed cases (3,196 active, 18,200 resolved, 247 deaths). There were 305 new cases Saturday from 1,326 completed tests, for a positivity rate of 23 per cent. The rate of active cases is 272.12 per 100,000 people. Over the past seven days, there have been a total of 1,928 new cases. The seven-day rolling average of new cases is 275. There were eight new reported deaths Saturday. Over the past seven days there have been a total of 37 new reported deaths. The seven-day rolling average of new reported deaths is five. The seven-day rolling average of the death rate is 0.45 per 100,000 people. The overall death rate is 21.03 per 100,000 people. There have been 327,151 tests completed. _ Alberta: 119,757 confirmed cases (9,987 active, 108,258 resolved, 1,512 deaths). There were 643 new cases Saturday from 12,969 completed tests, for a positivity rate of 5.0 per cent. The rate of active cases is 228.47 per 100,000 people. Over the past seven days, there have been a total of 4,387 new cases. The seven-day rolling average of new cases is 627. There were 12 new reported deaths Saturday. Over the past seven days there have been a total of 110 new reported deaths. The seven-day rolling average of new reported deaths is 16. The seven-day rolling average of the death rate is 0.36 per 100,000 people. The overall death rate is 34.59 per 100,000 people. There have been 3,061,844 tests completed. _ British Columbia: 63,484 confirmed cases (5,901 active, 56,455 resolved, 1,128 deaths). There were 508 new cases Saturday from 4,088 completed tests, for a positivity rate of 12 per cent. The rate of active cases is 116.36 per 100,000 people. Over the past seven days, there have been a total of 3,367 new cases. The seven-day rolling average of new cases is 481. There were nine new reported deaths Saturday. Over the past seven days there have been a total of 81 new reported deaths. The seven-day rolling average of new reported deaths is 12. The seven-day rolling average of the death rate is 0.23 per 100,000 people. The overall death rate is 22.24 per 100,000 people. There have been 1,044,931 tests completed. _ Yukon: 70 confirmed cases (zero active, 69 resolved, one deaths). There were zero new cases Saturday from six completed tests, for a positivity rate of 0.0 per cent. Over the past seven days, there have been a total of zero new cases. The seven-day rolling average of new cases is zero. There have been no deaths reported over the past week. The overall death rate is 2.45 per 100,000 people. There have been 6,216 tests completed. _ Northwest Territories: 31 confirmed cases (seven active, 24 resolved, zero deaths). There were zero new cases Saturday from 105 completed tests, for a positivity rate of 0.0 per cent. The rate of active cases is 15.62 per 100,000 people. Over the past seven days, there have been a total of six new cases. The seven-day rolling average of new cases is one. There have been no deaths reported over the past week. The overall death rate is zero per 100,000 people. There have been 9,064 tests completed. _ Nunavut: 267 confirmed cases (one active, 265 resolved, one deaths). There was one new case Saturday from 62 completed tests, for a positivity rate of 1.6 per cent. The rate of active cases is 2.58 per 100,000 people. Over the past seven days, there has been one new case. The seven-day rolling average of new cases is zero. There have been no deaths reported over the past week. The overall death rate is 2.58 per 100,000 people. There have been 7,241 tests completed. This report was automatically generated by The Canadian Press Digital Data Desk and was first published Jan. 24, 2021. The Canadian Press

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Twenty More COVID-19 Cases In NB Reported On Sunday – country94.ca

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Another day with COVID-19 cases in the double digits.

Public Health reported 20 new cases of COVID-19 for Sunday.

Ten cases in Zone 1 (Moncton region) are as follows:

  • four people 19 and under;
  • an individual 20-29;
  • an individual 30-39;
  • an individual 50-59;
  • two people 60-69; and
  • an individual 70-79.

The nine cases in Zone 4 (Edmundston region) are:

  • two people 19 and under;
  • an individual 20-29;
  • an individual 40-49;
  • three people 50-59;
  • an individual 60-69: and
  • an individual 80-89.

The one case in Zone 7 (Miramichi region) is as follows:

  • an individual 50-59.

All of the individuals are self isolating and the cases are under investigation.

“We are seeing encouraging trends, but the reliability of this information depends on those who have symptoms getting tested immediately, said Dr. Jennifer Russell, chief medical officer of health. “We will be more confident in our decision making – and zone restrictions are more likely to be eased – if more New Brunswickers, in all health zones, who have symptoms get tested.”

The total number of active COVID-19 cases currently is 334, with 14 more recovered cases reported since Saturday. Five patients are hospitalized with two in intensive care.

Below is a breakdown of the number of cases considered active in each zone:

  • Zone 1 (Moncton health region): 90
  • Zone 2 (Saint John health region): 36
  • Zone 3 (Fredericton health region): 36
  • Zone 4 (Edmundston health region): 144
  • Zone 5 (Campbellton health region): 19
  • Zone 6 (Bathurst health region): 7
  • Zone 7 (Miramichi health region): 2

Since cases began being reported in the province, New Brunswick has had 1,124 and 776 people have recovered. Thirteen people have died.

Zone 4 went into lockdown over the weekend. Zones 1, 2 and 3 remain at the red level, and zones 5, 6 and 7 are at the orange level.

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