from
https://www.earth.com/news/rare-star-explosion-will-be-visible-for-a-week/

Rare star explosion will be visible for a week

ByAndrei Ionescu
Earth.com staff writer
For the first time in eight decades, a celestial phenomenon will grace
our night sky, offering a once-in-a-lifetime chance to witness a star’s
brilliance with the naked eye during a dramatic explosion.

Known as T Coronae Borealis, or T CrB, this star resides 3,000
light-years from Earth in the Northern hemisphere’s expanse and is on
the brink of an intense outburst.

Star explosion in the Corona Borealis constellation
This event, set to occur this year, will see T CrB lighting up the
Corona Borealis constellation, shining as brightly as the famed North
Star, Polaris, for approximately one week.

The exact timing of this stellar spectacle remains uncertain, with NASA
forecasting its occurrence sometime between now and September. T CrB is
nestled within the Corona Borealis constellation, lying in a
semicircular pattern between the Bootes and Hercules constellations.

Rare astronomical event
The imminent outburst, classified as a nova, represents a rare
astronomical event that unfolds roughly every century. It happens when a
white dwarf star — comparable in size to the sun but collapsed – and a
red giant star — nearing the end of its life and expanding to about 74
times the sun’s size – venture too close to each other.

This proximity dramatically raises the red giant’s surface temperature
from about 4,000 to 5,800 degrees Fahrenheit to an astonishing 360,000
degrees Fahrenheit, prompting T CrB to expel its outer layers onto the
white dwarf’s surface.

Enormous thermonuclear explosion
The culmination of matter from the red giant triggers a nuclear
explosion, unleashing an energy burst up to 100,000 times greater than
the sun’s annual output.

Unlike a supernova, which obliterates the star, a nova such as T CrB’s
does not destroy the star system. Instead, the star cools down to its
original temperature and restarts its cycle.

Previous explosions of T CrB
Historical records trace T CrB’s notable eruptions back to 1946 and even
1866, with earlier accounts suggesting observations several centuries ago.

Notably, Reverend Francis Wollaston in 1787 and Abbott Burchard in 1217
documented witnessing a bright star in the Corona Borealis
constellation, hinting at earlier appearances of T CrB.

Brief yet intense display
This particular star explosion is unique for its brief yet intense
display, completing its cycle in merely a week.

NASA anticipates that the nova’s peak brightness will allow it to be
visible to the naked eye for several days, and with binoculars for just
over a week, before it fades away, potentially not to reappear for
another 80 years.

This upcoming event invites sky enthusiasts and the curious alike to
marvel at the wonders of our universe, showcasing the ephemeral yet
awe-inspiring nature of celestial phenomena.

Differences between nova and supernova explosions
The cosmos is a stage for some of the most spectacular and powerful
events known to science. Among these, nova and supernova explosions
stand out for their brilliance and the fundamental roles they play in
the universe’s lifecycle.

Despite the similarity in their names, novae and supernovae differ
vastly in their origins, mechanisms, and consequences. This article
demystifies these cosmic phenomena, highlighting their distinct
characteristics.

What is a nova?
As discussed above, a nova occurs in a binary star system, where a white
dwarf and a companion star orbit closely. The white dwarf, a dense
remnant of a star that has exhausted its nuclear fuel, pulls material —
primarily hydrogen — from its companion.

This material accumulates on the white dwarf’s surface, eventually
igniting in a thermonuclear explosion. The explosion causes the white
dwarf to brighten significantly, but it does not result in the star’s
destruction. Instead, the process may repeat if the white dwarf
continues to accrete material.

What is a supernova?
In contrast, a supernova is a cataclysmic event marking the death of a
star. Supernovae can occur in one of two primary ways:

Core-Collapse Supernova: This type happens at the end of a massive
star’s life cycle. When the star’s core runs out of nuclear fuel, it can
no longer support the outer layers against gravity. The core collapses,
resulting in a massive explosion that obliterates the star.

Type Ia Supernova: This type involves a binary system where a white
dwarf accretes material from a companion star, similar to a nova.
However, in this case, the white dwarf reaches a critical mass
(Chandrasekhar limit), leading to a runaway nuclear reaction that
completely destroys the white dwarf.

Key differences between novae and supernovae
Scale and Energy
The most striking difference lies in their scale and the energy
released. Supernovae are among the universe’s most energetic events,
outshining entire galaxies and releasing vast amounts of energy. Novae,
while still bright and powerful, are far less energetic and only cause a
temporary increase in brightness.

Frequency and Visibility
Supernovae are relatively rare events, occurring about once every 50
years in a galaxy the size of the Milky Way. Novae, on the other hand,
are more common, with several occurring in our galaxy each year. Despite
their rarity, supernovae can often be seen from greater distances due to
their immense brightness.

Outcome
A supernova marks the end of a star’s life, often leaving behind a
neutron star or black hole. The explosion disperses the star’s material
into space, contributing to the cosmos’s chemical enrichment. A nova
does not destroy the white dwarf. Instead, it merely expels the outer
layers of accumulated material, allowing the process to potentially repeat.

Contribution to the Cosmos
Both phenomena play significant roles in the cosmic lifecycle.
Supernovae are crucial for distributing elements necessary for life
throughout the universe, while novae contribute to the understanding of
stellar processes and the dynamics of binary star systems.

In summary, though novae and supernovae might be mistaken for similar
phenomena due to their names and explosive nature, they are
fundamentally different in their origins, mechanisms, and implications
for the cosmos. Understanding these differences not only enriches our
knowledge of the universe but also underscores the vast and varied
processes that govern the lifecycle of stars.

—–

Like what you read? Subscribe to our newsletter for engaging articles,
exclusive content, and the latest updates.

Check us out on EarthSnap, a free app brought to you by Eric Ralls and
Earth.com.

—–

On 3/20/2024 12:49 PM, a425couple wrote:
> from
> https://www.earth.com/news/rare-star-explosion-will-be-visible-for-a-week/
>
> Rare star explosion will be visible for a week
>
> ByAndrei Ionescu
> Earth.com staff writer
> For the first time in eight decades, a celestial phenomenon will grace
> our night sky, offering a once-in-a-lifetime chance to witness a star’s
> brilliance with the naked eye during a dramatic explosion.
>
> Known as T Coronae Borealis, or T CrB, this star resides 3,000
> light-years from Earth in the Northern hemisphere’s expanse and is on
> the brink of an intense outburst.

One hopes that the prediction is correct and that we do not get a nova
instead.

Thanks,
Lynn

On Wed, 20 Mar 2024 15:46:48 -0500, Lynn McGuire
<lynnmcguire5@gmail.com> wrote:

>On 3/20/2024 12:49 PM, a425couple wrote:
>> from
>> https://www.earth.com/news/rare-star-explosion-will-be-visible-for-a-week/
>>
>> Rare star explosion will be visible for a week
>>
>> ByAndrei Ionescu
>> Earth.com staff writer
>> For the first time in eight decades, a celestial phenomenon will grace
>> our night sky, offering a once-in-a-lifetime chance to witness a star’s
>> brilliance with the naked eye during a dramatic explosion.
>>
>> Known as T Coronae Borealis, or T CrB, this star resides 3,000
>> light-years from Earth in the Northern hemisphere’s expanse and is on
>> the brink of an intense outburst.
>
>One hopes that the prediction is correct and that we do not get a nova

Uhhn, aren't they predicting a "nova"?

Or did you intend to hope that we don't get a supernova? Personally,
at 3,000 Lys, I'd be happy with that one, too. Close enough to be
shiny, far enough away not to spoil the milk.

Not that, from the description of the system in Wiki, a supernova is
likely. Not unless the wee, white one gets eaten by Big Red. That
could be fun.

From a distance.

>instead.

Eventually, the big, red blobby one will run out of extra fuel and
these bursts will stop. Is there any modeling being done to calculate
how soon that may be?

Millions of novae after this one? Dozens? A couple?

Do we know how much the big red star loses with each boom?
A Ph. D. thesis in there, somewhere?

Oh, and the wee one isn't "the size of the Sun". it has about the
*mass* of Sol. Compacted into something about as wide as Earth. This
makes for some interesting Physics.

Big Red ain't "the size of the Sun", either. She's a *lot* wider and
more bloated though she, too, has about the same "weight" as our
friendly, white, huge star.

Just to calm the hyperbole a little, according to the system's Wiki
page: https://en.wikipedia.org/wiki/T_Coronae_Borealis there has been
a pre-boomy type of dimming that *indicates* a *possible* nova
sometime between March and September, 2024.

My money's on it not happening until at least January, next year when
it will be a focused Gamma-Ray Burster which will melt the planet.

This will not be the worst thing to happen then. :)

J.

>
>Thanks,
>Lynn

Le 2024-03-20 à 16:46, Lynn McGuire a écrit :
> On 3/20/2024 12:49 PM, a425couple wrote:
>> from
>> https://www.earth.com/news/rare-star-explosion-will-be-visible-for-a-week/
>>
>> Rare star explosion will be visible for a week
>>
>> ByAndrei Ionescu
>> Earth.com staff writer
>> For the first time in eight decades, a celestial phenomenon will grace
>> our night sky, offering a once-in-a-lifetime chance to witness a
>> star’s brilliance with the naked eye during a dramatic explosion.
>>
>> Known as T Coronae Borealis, or T CrB, this star resides 3,000
>> light-years from Earth in the Northern hemisphere’s expanse and is on
>> the brink of an intense outburst.
>
> One hopes that the prediction is correct and that we do not get a nova
> instead.
>
> Thanks,
> Lynn
>
How do you call a star exploding ? A nova.

Le 2024-03-20 à 13:49, a425couple a écrit :
> from
> https://www.earth.com/news/rare-star-explosion-will-be-visible-for-a-week/
>
> Rare star explosion will be visible for a week
>
> ByAndrei Ionescu
> Earth.com staff writer
> For the first time in eight decades, a celestial phenomenon will grace
> our night sky, offering a once-in-a-lifetime chance to witness a star’s
> brilliance with the naked eye during a dramatic explosion.
>
> Known as T Coronae Borealis, or T CrB, this star resides 3,000
> light-years from Earth in the Northern hemisphere’s expanse and is on
> the brink of an intense outburst.
>
> Star explosion in the Corona Borealis constellation
> This event, set to occur this year, will see T CrB lighting up the
> Corona Borealis constellation, shining as brightly as the famed North
> Star, Polaris, for approximately one week.
>
> The exact timing of this stellar spectacle remains uncertain, with NASA
> forecasting its occurrence sometime between now and September. T CrB is
> nestled within the Corona Borealis constellation, lying in a
> semicircular pattern between the Bootes and Hercules constellations.
>
> Rare astronomical event
> The imminent outburst, classified as a nova, represents a rare
> astronomical event that unfolds roughly every century. It happens when a
> white dwarf star — comparable in size to the sun but collapsed – and a
> red giant star — nearing the end of its life and expanding to about 74
> times the sun’s size – venture too close to each other.
>
> This proximity dramatically raises the red giant’s surface temperature
> from about 4,000 to 5,800 degrees Fahrenheit to an astonishing 360,000
> degrees Fahrenheit, prompting T CrB to expel its outer layers onto the
> white dwarf’s surface.
>
> Enormous thermonuclear explosion
> The culmination of matter from the red giant triggers a nuclear
> explosion, unleashing an energy burst up to 100,000 times greater than
> the sun’s annual output.
>
> Unlike a supernova, which obliterates the star, a nova such as T CrB’s
> does not destroy the star system. Instead, the star cools down to its
> original temperature and restarts its cycle.
>
> Previous explosions of T CrB
> Historical records trace T CrB’s notable eruptions back to 1946 and even
> 1866, with earlier accounts suggesting observations several centuries ago.
>
> Notably, Reverend Francis Wollaston in 1787 and Abbott Burchard in 1217
> documented witnessing a bright star in the Corona Borealis
> constellation, hinting at earlier appearances of T CrB.
>
> Brief yet intense display
> This particular star explosion is unique for its brief yet intense
> display, completing its cycle in merely a week.
>
> NASA anticipates that the nova’s peak brightness will allow it to be
> visible to the naked eye for several days, and with binoculars for just
> over a week, before it fades away, potentially not to reappear for
> another 80 years.
>
> This upcoming event invites sky enthusiasts and the curious alike to
> marvel at the wonders of our universe, showcasing the ephemeral yet
> awe-inspiring nature of celestial phenomena.
>
> Differences between nova and supernova explosions
> The cosmos is a stage for some of the most spectacular and powerful
> events known to science. Among these, nova and supernova explosions
> stand out for their brilliance and the fundamental roles they play in
> the universe’s lifecycle.
>
> Despite the similarity in their names, novae and supernovae differ
> vastly in their origins, mechanisms, and consequences. This article
> demystifies these cosmic phenomena, highlighting their distinct
> characteristics.
>
> What is a nova?
> As discussed above, a nova occurs in a binary star system, where a white
> dwarf and a companion star orbit closely. The white dwarf, a dense
> remnant of a star that has exhausted its nuclear fuel, pulls material —
> primarily hydrogen — from its companion.
>
> This material accumulates on the white dwarf’s surface, eventually
> igniting in a thermonuclear explosion. The explosion causes the white
> dwarf to brighten significantly, but it does not result in the star’s
> destruction. Instead, the process may repeat if the white dwarf
> continues to accrete material.
>
> What is a supernova?
> In contrast, a supernova is a cataclysmic event marking the death of a
> star. Supernovae can occur in one of two primary ways:
>
> Core-Collapse Supernova: This type happens at the end of a massive
> star’s life cycle. When the star’s core runs out of nuclear fuel, it can
> no longer support the outer layers against gravity. The core collapses,
> resulting in a massive explosion that obliterates the star.
>
> Type Ia Supernova: This type involves a binary system where a white
> dwarf accretes material from a companion star, similar to a nova.
> However, in this case, the white dwarf reaches a critical mass
> (Chandrasekhar limit), leading to a runaway nuclear reaction that
> completely destroys the white dwarf.
>
> Key differences between novae and supernovae
> Scale and Energy
> The most striking difference lies in their scale and the energy
> released. Supernovae are among the universe’s most energetic events,
> outshining entire galaxies and releasing vast amounts of energy. Novae,
> while still bright and powerful, are far less energetic and only cause a
> temporary increase in brightness.
>
> Frequency and Visibility
> Supernovae are relatively rare events, occurring about once every 50
> years in a galaxy the size of the Milky Way. Novae, on the other hand,
> are more common, with several occurring in our galaxy each year. Despite
> their rarity, supernovae can often be seen from greater distances due to
> their immense brightness.
>
> Outcome
> A supernova marks the end of a star’s life, often leaving behind a
> neutron star or black hole. The explosion disperses the star’s material
> into space, contributing to the cosmos’s chemical enrichment. A nova
> does not destroy the white dwarf. Instead, it merely expels the outer
> layers of accumulated material, allowing the process to potentially repeat.
>
> Contribution to the Cosmos
> Both phenomena play significant roles in the cosmic lifecycle.
> Supernovae are crucial for distributing elements necessary for life
> throughout the universe, while novae contribute to the understanding of
> stellar processes and the dynamics of binary star systems.
>
> In summary, though novae and supernovae might be mistaken for similar
> phenomena due to their names and explosive nature, they are
> fundamentally different in their origins, mechanisms, and implications
> for the cosmos. Understanding these differences not only enriches our
> knowledge of the universe but also underscores the vast and varied
> processes that govern the lifecycle of stars.
>
> —–
>
> Like what you read? Subscribe to our newsletter for engaging articles,
> exclusive content, and the latest updates.
>
> Check us out on EarthSnap, a free app brought to you by Eric Ralls and
> Earth.com.
>
> —–
What is rare is a nova or supernova that is close enough to the Earth to
be visible to the naked eye. Novas and super novas are not rare, as we
detect 1000's of them every year.

Kualinar wrote on 22/3/24 6:12 am:
> Le 2024-03-20 à 13:49, a425couple a écrit :
>> from
>> https://www.earth.com/news/rare-star-explosion-will-be-visible-for-a-week/

<Snip>

>> In summary, though novae and supernovae might be mistaken for similar
>> phenomena due to their names and explosive nature, they are
>> fundamentally different in their origins, mechanisms, and implications
>> for the cosmos. Understanding these differences not only enriches our
>> knowledge of the universe but also underscores the vast and varied
>> processes that govern the lifecycle of stars.
>>
>> —–
>>
>> Like what you read? Subscribe to our newsletter for engaging articles,
>> exclusive content, and the latest updates.
>>
>> Check us out on EarthSnap, a free app brought to you by Eric Ralls and
>> Earth.com.
>>
>> —–
> What is rare is a nova or supernova that is close enough to the Earth to
> be visible to the naked eye. Novas and super novas are not rare, as we
> detect 1000's of them every year.

WE do?? You're joking!!

Oh!! O.K., now that 'we' have super computers and Time exposure
photography, maybe more ARE located in other Galaxies but the visual
effect is not as SUPER!! ;-)
--
Daniel

Kualinar wrote:

> What is rare is a nova or supernova that is close enough to the Earth to
> be visible to the naked eye. Novas and super novas are not rare, as we
> detect 1000's of them every year.

You need to be careful throwing around numbers like that, In fact, this source...

https://www.sciencenews.org/article/number-milky-way-nova-explosions-per-year-pinned-down

... says that the number os novae detected each year is "about 50", and this source...

https://news.fnal.gov/2024/01/final-supernova-results-from-dark-energy-survey-offer-unique-insights-into-the-expansion-of-the-universe/

... says that the number of supernovae detected each year is about 300... so your guess of "1000's" is just that, a guess!

In alt.astronomy palsing <pnalsing@gmail.com> wrote:
> Kualinar wrote:
>
>> What is rare is a nova or supernova that is close enough to the Earth to
>> be visible to the naked eye. Novas and super novas are not rare, as we
>> detect 1000's of them every year.
>
> You need to be careful throwing around numbers like that, In fact, this source...
>
> https://www.sciencenews.org/article/number-milky-way-nova-explosions-per-year-pinned-down
>
> .. says that the number os novae detected each year is "about 50", and this source...
>
> https://news.fnal.gov/2024/01/final-supernova-results-from-dark-energy-survey-offer-unique-insights-into-the-expansion-of-the-universe/
>
> .. says that the number of supernovae detected each year is about 300... so your guess of "1000's" is just that, a guess!

When you use google to cite numbers you have to be very careful what
those numbers represent. Actual observations. Or calculations.
And for where -- our neighbourhood, the galaxy, somewhere in the universe.

We can see around 10 new novas per year in the Milky Way per years.
But most of the galazy is behind some screen or other and it's calculated
there are 40-50 per year in our galaxy.

Extrapolating out we can deduce given we cant see most of the universe "now"
there are many hundreds happening each year "somewhere".

The army of citizen scientists pouring over JWST and such images also
locate many 100s each year that happened within the past 13 (some now say 26)
billion years.

Kepler's pages have a table for their own efforts:
Year Num SN found
2007 572
2008 261
2009 390
....
2013 231

Kepler looks at only a tiny area of sky.

R Kym Horsell wrote:

> In alt.astronomy palsing <pnalsing@gmail.com> wrote:
>> Kualinar wrote:
>>
>>> What is rare is a nova or supernova that is close enough to the Earth to
>>> be visible to the naked eye. Novas and super novas are not rare, as we
>>> detect 1000's of them every year.
>>
>> You need to be careful throwing around numbers like that, In fact, this source...
>>
>> https://www.sciencenews.org/article/number-milky-way-nova-explosions-per-year-pinned-down
>>
>> .. says that the number os novae detected each year is "about 50", and this source...
>>
>> https://news.fnal.gov/2024/01/final-supernova-results-from-dark-energy-survey-offer-unique-insights-into-the-expansion-of-the-universe/
>>
>> .. says that the number of supernovae detected each year is about 300... so your guess of "1000's" is just that, a guess!

> When you use google to cite numbers you have to be very careful what
> those numbers represent. Actual observations. Or calculations.
> And for where -- our neighbourhood, the galaxy, somewhere in the universe.

> We can see around 10 new novas per year in the Milky Way per years.
> But most of the galazy is behind some screen or other and it's calculated
> there are 40-50 per year in our galaxy.

> Extrapolating out we can deduce given we cant see most of the universe "now"
> there are many hundreds happening each year "somewhere".

> The army of citizen scientists pouring over JWST and such images also
> locate many 100s each year that happened within the past 13 (some now say 26)
> billion years.

> Kepler's pages have a table for their own efforts:
> Year Num SN found
> 2007 572
> 2008 261
> 2009 390
> ....
> 2013 231

> Kepler looks at only a tiny area of sky.

Everything that you state here is fine and dandy, and in all probability correct, but the fellow I was answering clearly claimed that 1000's are "detected" every year, and not "calculated" or "extrapolated".