Astronomers detect the most massive neutron star ever measured

WVU astronomers help detect the most massive neutron star ever measured
Neutron stars are the compressed remains of massive stars gone supernova. WVU astronomers were part of a research team that detected the most massive neutron star to date. Credit: B. Saxton (NRAO/AUI/NSF)

West Virginia University researchers have helped discover the most massive neutron star to date, a breakthrough uncovered through the Green Bank Telescope in Pocahontas County.

The neutron star, called J0740+6620, is a rapidly spinning that packs 2.17 times the (which is 333,000 times the mass of the Earth) into a sphere only 20-30 kilometers, or about 15 miles, across. This measurement approaches the limits of how massive and compact a single object can become without crushing itself down into a black hole.

The star was detected approximately 4,600 light-years from Earth. One light-year is about six trillion miles.

These findings, from the National Science Foundation-funded NANOGrav Physics Frontiers Center, were published today (Sept. 16) in Nature Astronomy.

Authors on the paper include Duncan Lorimer, astronomy professor and Eberly College of Arts and Sciences associate dean for research; Eberly Distinguished Professor of Physics and Astronomy Maura McLaughlin; Nate Garver-Daniels, system administrator in the Department of Physics and Astronomy; and postdocs and former students Harsha Blumer, Paul Brook, Pete Gentile, Megan Jones and Michael Lam.

The discovery is one of many serendipitous results, McLaughlin said, that have emerged during routine observations taken as part of a search for gravitational waves.

"At Green Bank, we're trying to detect from pulsars," she said. "In order to do that, we need to observe lots of millisecond pulsars, which are rapidly rotating . This (the discovery) is not a gravitational wave detection paper but one of many important results which have arisen from our observations."

Artist impression and animation of the Shapiro Delay. As the neutron star sends a steady pulse towards the Earth, the passage of its companion white dwarf star warps the space surrounding it, creating the subtle delay in the pulse signal. Credit: BSaxton, NRAO/AUI/NSF

The mass of the pulsar was measured through a phenomenon known as "Shapiro Delay." In essence, gravity from a white dwarf companion star warps the space surrounding it, in accordance with Einstein's general theory of relativity. This makes the pulses from the pulsar travel just a little bit farther as they travel through the distorted spacetime around white dwarf. This delay tells them the mass of the white dwarf, which in turn provides a mass measurement of the neutron star.

Neutron stars are the compressed remains of massive stars gone supernova. They're created when giant stars die in supernovas and their cores collapse, with the protons and electrons melting into each other to form neutrons.

To visualize the mass of the neutron star discovered, a single sugar-cube worth of -star material would weigh 100 million tons here on Earth, or about the same as the entire human population.

While astronomers and physicists have studied these objects for decades, many mysteries remain about the nature of their interiors: Do crushed neutrons become "superfluid" and flow freely? Do they breakdown into a soup of subatomic quarks or other exotic particles? What is the tipping point when gravity wins out over matter and forms a black hole?

"These stars are very exotic," McLaughlin said. "We don't know what they're made of and one really important question is, 'How massive can you make one of these ?' It has implications for very exotic material that we simply can't create in a laboratory on Earth."

Pulsars get their name because of the twin beams of radio waves they emit from their magnetic poles. These beams sweep across space in a lighthouse-like fashion. Some rotate hundreds of times each second.

Since pulsars spin with such phenomenal speed and regularity, astronomers can use them as the cosmic equivalent of atomic clocks. Such precise timekeeping helps astronomers study the nature of spacetime, measure the masses of stellar objects and improve their understanding of general relativity.


Explore further

PALFA survey reveals eight new millisecond pulsars

More information: Relativistic Shapiro delay measurements of an extremely massive millisecond pulsar, Nature Astronomy (2019). DOI: 10.1038/s41550-019-0880-2 , https://nature.com/articles/s41550-019-0880-2
Journal information: Nature Astronomy

Citation: Astronomers detect the most massive neutron star ever measured (2019, September 16) retrieved 14 October 2019 from https://phys.org/news/2019-09-astronomers-massive-neutron-star.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
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Sep 16, 2019
As it dissipates energy and spin slows, is it likely to collapse to Black Hole ??

Sep 16, 2019
the general idea i've read suggests that if you were to have a neutron star slow to a stop (something that would take many billions of years), you also have to consider that over the course of this time it has been losing mass as well. So it's unlikely to collapse into a black hole then if it wasn't going to in the beginning.

Sep 16, 2019
the general idea i've read suggests that if you were to have a neutron star slow to a stop (something that would take many billions of years), you also have to consider that over the course of this time it has been losing mass as well. So it's unlikely to collapse into a black hole then if it wasn't going to in the beginning.

Unless you add the mass siphoned off the companion star...

Sep 16, 2019
As it dissipates energy and spin slows, is it likely to collapse to Black Hole ??

A Neutron star or a Black Hole needs two ingredients. The major event is the explosion that creates the pressure to melt the electrons into the protons, not an easy task.
The second is the mass that is enclosed by the implosion created dead center in the explosion.
If the mass is over three solar units it condenses into a black hole. If the mass in over 1.5 solar units it becomes a neutron star. At a solar unit it becomes a white dwarf.
There is leeway because we do not have enough observations to pin it exactly.

The article references the largest Neutron star ever measured, so now new guidelines will be coming soon.

To turn a neutron star into a black hole would require an additional sun's worth of mass added while experiencing a collision with a major size star at the same time.
Regular matter will not accumulate, it is thin like fog compared to the neutrons and will not stick tight.

Sep 16, 2019
the op wasn't asking if it would collapse if it siphoned mass from elsewhere though. That's kind of implied.

I think the question they actually asked comes from the idea that centripetal force is countering gravity enough in a sufficiently massive neutron star to keep it from being dense enough to collapse into a black hole...and that as that angular momentum bleeds off, gravity finally wins and it becomes a black hole.

The problem with that theory is that neutron stars slow down so slow, that it will be losing a decent amount of mass by the time it slows down. Also, that it would have to be spinning at a significant fraction of the speed of light for it to counter the gravity significantly. I think measurements put the escape velocity of neutron stars at like .4C ....however that will depend on size. The fastest pulsars are a magnitude slower than that at least. So even the fastest ones found will not be spinning fast enough to make a difference to its density.

Sep 16, 2019
"The mass of the pulsar was measured through a phenomenon known as "Shapiro Delay." In essence, gravity from a white dwarf companion star warps the space surrounding it, in accordance with Einstein's general theory of relativity. This makes the pulses from the pulsar travel just a little bit farther as they travel through the distorted spacetime around white dwarf. "

And STILL they have to make a reference to Minkowski's "spacetime", pretending that the unsubstantiality of 'time' is somehow having something to do with the physicality of the PULSES from the PULSAR as those pulses travel through "DISTORTED SPACETIME". HOW do they come up with that? Exactly WHAT IS THIS SPACETIME that can be distorted? They say that Spacetime is a 4th Dimension. If it is a dimension, then HOW is it able to distort itself?

YES, it is GRAVITY from the White Dwarf Star that warps the space surrounding the Star -- NOT Spacetime.

Sep 16, 2019
darth, in general, based on my limited knowledge of these subjects, i agree with most of your comments

except i am struggling to comprehend how a neutron star
(after all the excreta by novae)
can lose any more mass?

please elucidate, cause frankly, i do not understand what mechanism is possible to whittle down a neutron star

Sep 16, 2019
It is just silly to accept the idea these stars are spinning at the claimed rates as shown in the cartoon. Talk about impossible woo.
What does likely occur is that jet remains pointed at Earth and what we are observing are pulses in the electric currents of the jets, analogous to a strobe light.

Sep 16, 2019
It is just silly to accept the idea these stars are spinning at the claimed rates as shown in the cartoon. Talk about impossible woo.
What does likely occur is that jet remains pointed at Earth and what we are observing are pulses in the electric currents of the jets, analogous to a strobe light.


Lol.

Sep 17, 2019
What does likely occur is that jet remains pointed at Earth and what we are observing are pulses in the electric currents of the jets, analogous to a strobe light.


Just leave man, don't waste your time here...collaborate with the Chinese or Iranians - they have little incentive to prop up the false framework of western science - develop a coherent theory and win your no-bell prize.

Sep 17, 2019
This @cantthink idiot is still here? It was last seen on this site denying the 3 stars in Alpha Centauri orbit each other, LOL.

Sep 17, 2019
2.2 solar masses is right at the theoretical limit, but the black hole range from LIGO goes down to some 3 solar masses as of yet. Nice to have two independent methods though.

As it dissipates energy and spin slows, is it likely to collapse to Black Hole ??


It's complicated, but Darth Ender gives it a good, well, spin.

If it was just energy loss it would decrease the likelihood (since mass and energy are gravitational sources in general relativity). But you are likely thinking of the angular momentum vs gravitational force momentum balance in a spinning neutron start to Kerr black hole collapse.

the false framework of western science


Like a good crank you have to make an obviously false assertion that the very article you comment under rejects.

Blocked for crank trolling.

Sep 17, 2019
And STILL they have to make a reference to Minkowski's "spacetime"


Why do you emphasize still? Of course they reference spacetime, as that's the physical reality we live in. Did you think that just because you've spewed some garbled nonsense on some articles that scientists worldwide would stop accepting known physics? Of course you would, that's par for the course.

It is just silly to accept the idea these stars are spinning at the claimed rates as shown in the cartoon.
You know what's really silly? The theory you put forth to explain the orbits of stars at the center of our galaxy. Stars building up charges to be repulsed by some mysterious plasmoid at the galactic center. Those same stars flipping charge sign, then being attracted to this plasmoid, etc., that they might maintain stable elliptical orbits.


Sep 17, 2019
A piece the size of a sugar cube weighs 100 million pounds.
Its a milli-second pulsar so it makes one revolution at least every 1000/sec.
Its 15 miles in diameter.

From that information we should be able to determine the angular momentum of that 100 million pound sugar cube sitting on the surface. And what gravitational force is required to hold it there.
Anyone willing to crunch the numbers?

Sep 17, 2019
A piece the size of a sugar cube weighs 100 million pounds.
Its a milli-second pulsar so it makes one revolution at least every 1000/sec.
Its 15 miles in diameter.

From that information we should be able to determine the angular momentum of that 100 million pound sugar cube sitting on the surface. And what gravitational force is required to hold it there.
Anyone willing to crunch the numbers?
Sure, but check the math.

Mass of sugar cube, m = 100,000,000 lbs = 45,359,237 kg
Radius, r = 7.5 miles (1.609 km/mile) = 12.0701 km = 12070.1 meters
Mass of neutron star, M = M = 2.71 solar masses = 2.71 × 1.989 ×10^30 kg = 5.39 ×10^30 kg
Newton's constant, G = 6.67408 ×10^−11 N⋅m^2/kg^2
Circumferential distance in one revolution, d = 2 × pi × 12070.1 m, so velocity is given by
v = d meters/revolution × 1000 revolution/sec = 75,838,674.9 m/s, which is ~ 0.25 c

Multiply v by the mass of the sugar cube for momentum...

-cont'd-

Sep 17, 2019
-cont'd-

here is a calculation for the centrifugal force experienced by the sugar cube, using
F = mv^2/r
(45359237 kg)(75,838674.9 m/s)^2/(12070.1 m)
= 21,614,059,596,709,953,711.528684103694 kg m/s/s
= 196,406,959,555,303,349,376.66115245027‬ N
= 1.9640695955530334937666115245027 × 10^20 N

So the gravitational force of attraction is given using
F = mg, with
g = GM/r^2
F = (4.5359237 × 10^7)(6.67408 × 10^-11)(5.39 × 10^30)/(1.4568731401 × 10^8)
~ 112 × 10^34 N

Hopefully that's correct ...

Sep 17, 2019
...well i added the exponents in my head, looks like it should be more like 112 × 10^18 N ...

So either there's a mistake in the physics, or my choice of units, or something because it looks like gravity isn't strong enough to keep the cube from flying off into space... gotta check the escape velocity next, unless anyone can point out the error ...

Sep 17, 2019
...well i added the exponents in my head, looks like it should be more like 112 × 10^18 N ...

So either there's a mistake in the physics, or my choice of units, or something because it looks like gravity isn't strong enough to keep the cube from flying off into space... gotta check the escape velocity next, unless anyone can point out the error ...

The only error is accepting the gravity only conjectured as being valid.

Sep 17, 2019
The only error is accepting the gravity only conjectured as being valid.


Anyway, can you please explain the whole stars orbiting stably around a plasmoid thing?
Really struggling with that one.

Sep 17, 2019
...well i added the exponents in my head, looks like it should be more like 112 × 10^18 N ...

So either there's a mistake in the physics, or my choice of units, or something because it looks like gravity isn't strong enough to keep the cube from flying off into space... gotta check the escape velocity next, unless anyone can point out the error ...


The sugar cube is quoted as being 100 million tons not lbs so = 90718474000kg

Sep 17, 2019
Calculating the escape velocity:

Vesc = sqrt(2GM/r)
= sqrt(2 × 6.67408 × 10^-11 × 5.39 × 10^30 kg / 12070.1 m)
= 244,146,020.8 m/s, which is about 0.8 c

...all i can think of is binding energy... ?

Sep 17, 2019
The sugar cube is quoted as being 100 million tons not lbs so = 90718474000kg
Ahh, thank you, that's much better:

New calculation for force of gravity on the cube at the neutron star's surface:
F = (90,718,474,000)(6.67408e-11)(5.39e+30) / (1.4568731401e+8)
= 224,003,174,510,968,444,753,469.16995439
~ 2.24 ×10^23 N

Sep 17, 2019
...however, here is a new calculation for the centrifugal force experienced by the sugar cube, using
F = mv^2/r
= (90,718,474,000 kg)(75,838674.9 m/s)^2/(12070.1 m)
= 162,450,559,942,219,403,428,349,262.15319
~ 1.62 ×10^26 N

hmmm

Sep 17, 2019
Alpha Centauri is right next door, and it's three stars orbiting one another. We can see it and there isn't any question. If you want to see a system with a big star and a little star, and the little star obviously orbiting the big star, Sirius is only about twice as far away.

None of this is controversial; we've been looking at it for centuries. You don't need a particularly expensive telescope to determine these orbits, but you do need a good mount so that you can measure them accurately. We've had good enough mounts for centuries too; and you can use a sextant or octant as well. Sir Edmund Halley used equipment like this to predict the return of his eponymous comet.

Anyone who doubts this can go get their own telescope and spend a couple of years confirming it. It will take a couple years for the stars in question to move enough to be measured.

Sep 17, 2019
Ah ha. There's actually a maximum, limiting rotational frequency for neutron stars, calculated to be around 300 -- 700 Hz. Said to be consistent with observation. See: Crust breaking and the limiting rotational frequency of neutron stars

In cases where the crust breaks, the neutron star would become a source of continuous gravitational waves. It was a good question, sparcboy, i learned some fascinating possibilities trying to answer it, thanks.

Sep 17, 2019
What does likely occur is that jet remains pointed at Earth and what we are observing are pulses in the electric currents of the jets, analogous to a strobe light.


Just leave man, don't waste your time here...collaborate with the Chinese or Iranians - they have little incentive to prop up the false framework of western science - develop a coherent theory and win your no-bell prize.
says iamvik04

And another one bites the dust.
LOL
You seem to have earned the ire of Torbjorn the Swedish Blocker, although it was apparent that you were ranting at CD85, and not ranting at Torbjorn himself. I wonder why Torbjorn took your comment as a personal affront when it wasn't directed toward him. And he has now blocked you.
Perhaps Torbjorn has forgotten the famous Swedish tradition of 'inclusivity', where he lives in a country where Muslims are welcome to repopulate Sweden and indigenous Swedes are more often turning gay.

Sep 17, 2019
@SEU

Anything of value to add?

That makes logical sense - added

Sep 17, 2019
@Scientologist_Sperm_Unit's only contribution is efforts to get out of cases for having molested children. This appears to be what scientologists "believe in."

Sep 17, 2019
And STILL they have to make a reference to Minkowski's "spacetime"


Why do you emphasize still? Of course they reference spacetime, as that's the physical reality we live in. Did you think that just because you've spewed some garbled nonsense on some articles that scientists worldwide would stop accepting known physics? Of course you would, that's par for the course.
says jingles

You included MY comment along with CD85's, which made it appear that they were both mine. You should know better than to do that.
Actually, there is nothing KNOWN about the so-called 'Spacetime'. It is merely a part of the math equations, but no one has ever SEEN or DETECTED Spacetime. It is WOO that had to be included only because it was one of Einstein's (actually belonging to H. Minkowski) many math terms (t) that was never really explained as to its substance. It is still nonphysical, but it's in the textbooks, so no scientist dares to take it out.

Sep 17, 2019
@Scientologist_Sperm_Unit's only contribution is efforts to get out of cases for having molested children. This appears to be what scientologists "believe in."
says the liar Schneib

Still telling lies about me and others? Why do you wish to condemn yourself and send your own soul to the hellfire which you so richly deserve, Schneib? Is it in your DNA to be such a LIAR?
There has to be a good reason for what you do. I think that it is YOU that would like to molest young boys, while alleviating your feelings of guilt by accusing others of it.

Sep 17, 2019
@SEU

Anything of value to add?

That makes logical sense - added
says jimmybobs

I only speak the truth, jimmy booboo. You may not understand or accept that truth, but nevertheless, it's there for all to read and explore.

Sep 17, 2019
Ah ha. There's actually a maximum, limiting rotational frequency for neutron stars, calculated to be around 300 -- 700 Hz. Said to be consistent with observation. See: https://arxiv.org...4952.pdf

In cases where the crust breaks, the neutron star would become a source of continuous gravitational waves. It was a good question, sparcboy, i learned some fascinating possibilities trying to answer it, thanks.
says Protoplasm

What does that 'crust' consist of, and why is there a crust on/in a Neutron star? AFAIK, crusts don't form on any other type of Star. Why on a Neutron star?

Sep 17, 2019
why sillyegghead?
why the fuck not...

you put on this big spectacle of fraudulent honesty of pretentious piety masking your rabid inquisitor's savagery

in your eagerness to denounce peer-reviewed scientific works?
your complete lack if principles, & honor
define you as an apostate heretic
foolishly screaming your madness
at whichever unfortunate godling
you've chosen this week as your victim to accept your abuse of reality

which is why you are infesting the Real Science forums

your fellow wethers of yech!
among all the other sheeple looneyticks, fakirs, denierbots
& contagious cultists of every religious craze, even the most depraved sleaze...

have driven you off their sites
cast you away to be shunned
declared you anathema, banished you from their covens
as a disgraced abomination

Sep 18, 2019
@jingles

Regarding the alleged 'Spacetime', you might find this interesting from New Scientist:

https://www.newsc...reality/

Sep 18, 2019
@SEU

What is the truth?

Sep 18, 2019
@SEU

What is the truth?


jesus christ don't ask him that @jimmybobber

Sep 18, 2019
My apologies hat1208.


Sep 18, 2019
A Neutron Star, not quite getting, this hang, of Conglomeration!

J0740+6620, at 2.17 solar masses
Is this most massive neutron star ever measured?

A neutron star
Is this collapsed core
Of a giant star
Which before collapse
Had a total mass
Of between 10 and 29 solar masses
Neutron stars are the smallest and densest stars
Not counting black holes
Neutron stars have a radius
Of 10 kilometres
A mass
Of about 1.4 solar masses
They result from the supernova explosion
Of a massive star
Combined with gravitational collapse
That compresses
The core past white dwarf star density
To that of atomic nuclei

What With
This collapsed core
A giant star before collapse
Gravitational collapse
Compresses the core to that of atomic nuclei
It Seems, to be making, a very good impression, of getting this hang, of Conglomeration!

Sep 18, 2019
You included MY comment along with CD85's, which made it appear that they were both mine.

And? Each of you know which comment you authored.

Actually, there is nothing KNOWN about the so-called 'Spacetime'.

Sure, if you want to boil things down to a Cartesian level of the only thing we know is that we exist, then yeah I agree.

WOO

Ahh, finally a topic in which you are the expert!

Sep 18, 2019
What does that 'crust' consist of, and why is there a crust on/in a Neutron star? AFAIK, crusts don't form on any other type of Star. Why on a Neutron star?
"Star crust is 10 billion times stronger than steel | New Scientist

https://www.newscientist.com ' article ' dn16948-star-crust-is-10-billion-ti...
Apr 14, 2009 - The crust of a neutron star is strong enough to hold up ultra-dense mountains, a new simulation suggests. As the star spins, these bumps could ..."

-Lazy + ignorant + inane = pussytard

Sep 18, 2019
@TBL
Like a good crank you have to make an obviously false assertion that the very article you comment under rejects.

Blocked for crank trolling.


??? please look up the word "sarchasm" on google...

Sep 18, 2019
@torbjorn, I'll stick up for @iamvik.

@iamvik, I acknowledge there were elements of your post that made its sarcastic intent clear, but @torbjorn isn't used to this vein of mockery. He's getting frustrated dealing with the nutjobs who are given free rein here.

Sep 19, 2019
My apologies hat1208.



Thank you. I thought the, "jesus christ" would make his head explode.

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