We are still astonished at the ability to see a dense, small object hidden within an explosion cloud just a few thousand light years away.
All accounts seem to indicate that it is. neutron starAlthough it is an unusual one, This object has the lowest mass measured, at 77 percent of Sun’s total mass.
PreviouslyThe mass of the Sun is 1.17 times that of a neutron star measured by.
The latest discovery is not only smaller than expected, but it is also significantly lower that the theoretical minimum neutron star mass. This suggests either there’s some gap in our understanding of these ultradense objects… or what we’re looking at is not a neutron star at all, but a peculiar, never-before-seen object known as a ‘strange’ star.
These stars are among the most dense objects in the Universe. These are what remains after a massive star with a mass between 8 and 30 times that of the Sun has died. If the star runs out material to fuse in its core it becomes supernova and ejects its outer layers into space.
The core is no longer supported by the pressure of fusion and collapses in itself to form an object so dense that atomic nuclear nuclei squish together. Electrons are forced to be intimate with protons, long enough to enable them to turn into neutrons.
These compact objects average around 1.4x the Sun’s mass, but theory suggests they could be as large as about 2.3 solar massesThis is a mere 1.1 solar mass. All this material packed into a 20-kilometer (12 mile) sphere makes every teaspoonful of neutron stars material weigh somewhere in the range of 1.1 to 1.2 solar masses. 10,000,000And Many billion tons.
Stars can become dense objects with masses that are higher or lower than those of neutron stars. Black holes form from heavier stars Lighter stars turn into white dwarfs – less dense than neutron stars, with an upper mass limit of 1.4 solar masses, though still pretty compact. This is the. The fate of our Sun.
This study examines the neutron star, which is located at the center in a supernova remnant. HESS J1731-347The previous calculation had shown that the sat more than 10,000 light-years distant. However, poor distance measurements are one of the biggest problems in studying neutron star. It’s difficult to get accurate measurements of other star characteristics without a precise distance.
HESS J1731-347 was recently visited by a second star that is optically bright. From this, using data from the Gaia mapping survey, a team of astronomers led by Victor Doroshenko of Eberhard Karls University of Tübingen in Germany were able to recalculate the distance to HESS J1731-347, and found it’s much closer than thought, at around 8,150 light-years away.
It was necessary to refine previous estimates of the neutron stars’ other characteristics, including its mass. Doroshenko’s colleagues used observations of the neutron stars X radiation to determine its radius. It was then able to reduce its mass to 0.77 solar masses.
It could be a neutron-star as we know it but a hypothetical object that has yet to be positively identified in nature.
“Our mass estimate makes the central compact object in HESS J1731-347 the lightest neutron star known to date, and potentially a more exotic object – that is, a ‘strange star’ candidate,” The researchers wrote in their paper.
A strange star is thought to look a lot like one of the neutron stars, but it contains more fundamental particles known as strange quarks. Quarks are subatomic fundamental particles that combine to create composite particles like protons and neutrons. There are six types of quarks, or flavors: up, charm, strange and bottom. Up and down quarks make up neutrons and prototons.
Theories suggest that subatomic particles are broken down into their constituent quearks in the highly compressed environment of a neutron Star. This model suggests that strange stars are composed of matter with equal amounts of up, down and strange quarks.
Strange stars should form under masses large sufficient to make them really push the limits. But since the rulebook on neutron stars is invalidated when enough quarks get involved in the formation of neutron stars, there’s no lower limit. This means that it is possible for this neutron star to be a strange star.
This would be very cool. For decades, physicists have been looking for quark material and strange quark matters. However, while a strange star is certainly possible, the greater likelihood is that what we’re looking at is a neutron star – and that, too, is extremely cool.
“The obtained constraints of mass and radius are consistent with a neutron star interpretation. These constraints can be used by astronomers to improve astrophysical constraints of the equation state of cold dense material under this assumption.” The researchers write.
“A light neutron star of this nature, regardless its assumed internal composition, seems to be an intriguing object from an astrophysical standpoint.”
It is difficult to determine how such a neutron star could have formed using current models. Whatever it may be, HESS J1731-347’s dense object is going to have something for us to learn about the afterlives of massive star stars.
The research of the team has been published in Astronomy of Nature.
