A strange star is a quark star made of strange
quark matter.
They form a subgroup under the quark star
category.Strange stars might exist without
regard of the Bodmer–Witten assumption of
stability at near-zero temperatures and pressures,
as strange quark matter might form and remain
stable at the core of neutron stars, in the
same way as ordinary quark matter could.
Such strange stars will naturally have a crust
layer of neutron star material.
The depth of the crust layer will depend on
the physical conditions and circumstances
of the entire star and on the properties of
strange quark matter in general.
Stars partially made up of quark matter (including
strange quark matter) are also referred to
as hybrid stars.This theoretical strange star
crust is proposed to be a possible reason
behind the ever mysterious fast radio bursts
(FRBs).
While this is of course still theoretical;
there is good evidence the researchers from
this paper provide that point to the collapse
of these strange star crusts to be a possible
FRB point of origin.
For said crust to collapse from a strange
star it must accrete matter from its environment
in some form.
This release of even small amounts of its
matter cause a cascading effect on the stars
crust.
Which is thought to result in a massive release
of magnetic energy as well as electron and
positron pairs; in the initial first stages
of the collapsing stage.
This release of high energy particles and
magnetic energy in such a short period of
time causes the newly released electron/positron
pairs to be directed towards the poles of
the strange star due to the increased magnetic
energy created by the initial secretion of
the strange stars matter.
Once these electron/positron pairs are directed
to the poles they are then ejected at relativistic
velocities, which is then believed to be one
of the causes to what astronomers in the past
11 years of observing this phenomenon known
as FRBs could be.
Original scientific paper source
Simpler breakdown of said scientific paper.
Theoretical investigations have revealed that
quark stars might not only be produced from
neutron stars and powerful supernovae, they
could also be created in the early cosmic
phase separations following the Big Bang.
If these primordial quark stars transform
into strange quark matter before the external
temperature and pressure conditions of the
early universe makes them unstable, they might
turn out stable, if the Bodmer–Witten assumption
holds true.
Such primordial strange stars could survive
to this day.
== Characteristics ==
Recent theoretical research has found mechanisms
by which quark stars with "strange quark nuggets"
may decrease the objects' electric fields
and densities from previous theoretical expectations,
causing such stars to appear very much like—nearly
indistinguishable from—ordinary neutron
stars.
This suggests that many, or even all, known
neutron stars might in fact be strange stars.
However, the investigating team of Prashanth
Jaikumar, Sanjay Reddy, and Andrew W. Steiner
made some fundamental assumptions that led
to uncertainties in their results large enough
that the case is not finally settled.
More research, both observational and theoretical,
remains to be done on strange stars in the
future.Other theoretical work contends that:
"A sharp interface between quark matter and
the vacuum would have very different properties
from the surface of a neutron star"; and,
addressing key parameters like surface tension
and electrical forces that were neglected
in the original study, the results show that
as long as the surface tension is below a
low critical value, the large strangelets
are indeed unstable to fragmentation and strange
stars naturally come with complex strangelet
crusts, analogous to those of neutron stars.
== References ==
