Authors_;
**Miss
Upasana Bhattacharya- Only Daughter of
Professor Pranab kumar Bhattacharya,
Student, Mahamya apartment; Block B, Mahamyatala, 54 NSC Bose Road;
Garia, kol-84. WB, India
**Professor
Pranab kumar Bhattacharya MD (Calcutta
univ.) FIC
Path(India); Professor and Head, Department of Pathology, School of Tropical Medicine-kolkata; 108, C.R Avenue ,Kolkata-73, WB, India; Ex- Professor
and HOD Ophthalmic Pathology RIO kolkata-73, & of WBUHS and Ex- Professor
of Institute of Post Graduate Medical Education & Research,244 AJC Bose
Road, Kolkata-20, West Bengal, India{
Member & Member Secretary of Board of Studies of West Bengal University of Health
Sciences(WBUHS), DD36, Salt Lake City Sector-1, kolkata, West Bengal for Undergraduate, Post Graduate and Post
Doctoral studies in Pathology and of DCP
courses under WBUHS. Examiner of Post Doc PhD & Thesis Evaluator Adjudicator of MD/DM/PhD of
WBUHS
***Mr.Ritwik Bhattacharya B.com(calcutta Univ) *** Miss Rupsa Bhattacharya *** Mr Soumyak Bhattacharya
BHM(IGNOU], MSc student PUSHA Govt of India, New Delhi , India
* & *** 7/51 purbapalli, Po-sodepur Dist 24
parganas(north) , Kolkata-110,WestBengal ,
India
**** Mrs. Dalia Mukherjee BA(honors)
Cal.Univ **** Oaindrila Mukherjee- BA Honors(English) cal univ; Miss Oaeshi
Mukherjee- Student **** Mr Debasis
Mukherjee BSc(Calcutta Univ) of
Residence Swamiji Road, South Habra, 24
Parganas(north), West Bengal, India
What is the fate of this
Universe?
Cosmos is Expanding
It is not the first time that an astronomical discovery has revolutionized
our ideas about our Universe. Only a hundred years ago, the Universe was
considered to be a calm and a peaceful place, no larger than our own galaxy,
the Milky Way. The cosmological clock was then as if ticking reliably and
steadily and the Universe was eternal. Soon, however, a radical shift changed
this picture. At the beginning of the 20th century the American amateur lady
astronomer “Henrietta Swan Leavitt” found a way of measuring distances to far away
stars. At the time, some women
astronomers were denied access to the large telescopes, but they were then
frequently employed for the cumbersome tasks of analyzing photographic plates
taken of these large telescopes. Henrietta Leavitt had thus enjoyed enough scope of analyzing
& she could havoc
scope of studying thousands of pulsating stars, they called them “Cepheids”,
and she found that the brighter ones had longer pulses. Using this information,
Leavitt could calculate the intrinsic brightness of Cepheids and it was
immediately accepted by rest of world. She told ,If the distance of just one of the
Cepheid stars is known, the distances to other Cepheids can be established –
the dimmer its light, the farther away the star is”. A reliable standard candle
thus was born, a first mark on the cosmic yard stick that is still being used
today. By making use of Cepheids, astronomers would soon concluded that the “Milky
Way” is just one of many millions galaxies in our observable Universe. And in
the 1920s, the astronomers got access to the world’s then-largest telescope
Mount Wilson in California
The coming and going of the cosmological constant
What was observed in
space time had already been suggested by
theoretical calculations. In 1915, the great intelligence & mind Nobel Laureates in physics “Albert
Einstein” published his “General Theory of Relativity”, which had been the
foundation of our understanding of the Universe ever since the publication. The theory described a Universe that has to
either shrink ( Big Crunch)or to
expand. It was really a disturbing conclusion for mathematician. This
disturbing conclusion was reached about a decade before the discovery of the
ever-fleeing away galaxies. Not even
Einstein could reconcile the fact that the Universe was not static ( steady
State theory of JB Narleiker and Fred Howel-
Nobel laureates in physics). So in order to stop this unwanted cosmic
expansion, Einstein had no other option
but to add a constant to his equations that he himself called the cosmological constant.
Later, Einstein would consider the insertion of the cosmological constant was
in fact
a big mistake for him.
However, with the observations made in 1997–1998 that are awarded the 2011
Nobel Prize in Physics, we can conclude that Einstein’s cosmological constant
– put in for the wrong reasons – was actually brilliant one thought in fact. The
discovery of the expanding Universe was a groundbreaking first step towards the
now standard view that the Universe was created in the Big Bang almost 14
billion years ago. Both time and space began only then. Ever since, the Universe has been expanding; like raisins in a raisin cake swelling in
the oven, But No body still answered what is beyond that Planck’s moment of
Big Bang Creation of our universe?. Was there another universe? Was there
multiple universe?
Stars last too
long in the universe.
For an amateur astronomers/ or theoretical
physicist like myself and my brother Mr Rupak
Bhattacharya, to see any evolution of a star or death of a star, in the course
of his/their life time, unless he/they is/are lucky enough to see one star
destroying itself in a phenomenon called
supernova or in a nova explosion or turning towards a Red giant .
My then old and diseased father[ He was diseased in 2009 April] , late Mr.
Bholanath Bhattacharjee and my mom late Mrs Bani Bhattacharya ( She was
diseased in May 2006) of our residence7/51 Purbapali, Po-sodepur,24
parganas (north) kolkata-110, West Bengal, India , they used to teach our
brothers and only sister in our younger
ages, child ages, with their built up notion like this”….. Stars are long lived
objects with ages, they are as old as our galaxy is, as old as our universe is
and they are symbol of eternity [heaven and hell their Planets are] they may be
2.5 billion years – 3 billion years old from a first generation stars explosions and are almost perfect cosmic mile markers even very
close to Big Bang. And many such stars might have habitable planets like our Earth
where civilization grew but better form of technological civilization exists
there and we intelligent human beings come from there and returns back after
our death there according our acts in this planet. They belived in soul ! God!
Creator! Big Bang! Today we know that looking at a supernova of
a very distant star almost at horizon of the universe, or of a Nebula, we can
understand the mystery of creation of the Universe, the Big Bang it self. They
are really the symbol of the eternity.
Edington suspected, that the nuclear reactions in the interior of the
stars are primary sources of energy for it’s luminosity and fusion of
hydrogen to make Helium and that can take place in it, in time bound scale for
this ranges, from millions to millions years. Our sun has lost it’s
brightness by more then 1% from it’s birth, due to change in it’s internal
structure for past 107 years. But the question remains how these supernovas explode? What is the
mechanism behind it? No physics probably
answered it yet. Here
may be some explanations by my brothers
Rupak Bhattacharya and Ritwik Bhattacharya
the authors
If
we consider the mode of generation of energy in the star, nuclear process
provide the only source of energy adequate to keep the stars ongoing luminous. The
nuclear fusion in which Hydrogen is built up into Helium, can function
sufficient fast at temperature, like those at central core of star (12-25
million degrees). The Helium burning process are important 1) Carbon
Nitrogen cycle at which a carbon-12 nucleus (12C) capture proton
and is converted into 13C, Nitrogen-4 and nitrogen –15. At a
final temperature, a proton leads to a fusion yielding original 12C
nucleus to a Helium nucleus .2) The Proton- Proton process, in which
protons are built direct Helium nuclei through steps, involving first in
production of a deuterium and helium3 nuclei to form Helium4
nucleus and two protons. 3) Carbon burning process where 12C
nucleus undergoes fusion reaction in the interior of a star producing neutron,
proton, and Alfa particles with huge temperature. The first reaction probably
dominates into the star, applicable to more massive stars then Sun. The
second and third reaction is applicable for Sun and in less massive stars then
Sun respectively. Thermonuclear reactions like those in a hydrogen bomb are
powering the Sun in a contained and continuous explosions converting some four
hundred millions tons (4x1014 grams) of hydrogen into helium. When
we look up in the sky in night and see the stars we see them shining because of
distant nuclear fusion in them .But hydrogen fusion can not continue for
ever. Our Sun is ~ 4.7109 years
old star. The energy produced in our ordinary star Sun in each second, is
equivalent to the destruction of 41/2 millions tons of hydrogen mass in every
second, a mere fleabite compared with the mass of the Sun which is two thousand
billion and billion tones. In the Sun or in any other stars, there is limited
so much hydrogen in it’s hot interior. Although Helium is predominating as
net fusing of Hydrogen, other elements like “carbon”, “Iron”, “L
element” “Manganese” “Chromium”, EU, yttrium, Magnesium, SR, Nickel,
Osmium are also built up in the interior of the stars. Arnett and Truran
[Arnett W.D and Truran. JW –Astrophysics.J-Vol157;P339,1969] showed
that nuclear reaction net work in the sun when 12C nuclei began to under go the fusion reaction in
the interior of sun many elements are produced such as
12C+12C
à
23Na+P+2.238mev à23Mg+
n+2.623mev-à20Ne+ 27Al
+4.616mev and the reaction goes on endlessly. A large number of computed
reactions are possible as the liberated neutron and gamma particles begin reaction
with all the nuclear species generated within the hydrogen fusion. In fact
Arnett and Truran produced 99 different reactions only in 12C carbon
burning net work and 23Na,20Ne,
24Mg,27Al,29Si, and some31P elements are also produced. Beside these
Li, Be, B ( Known as leptons)are also produced in the stars due to hydrogen
burning. Another more most elementary particles are produced in huge
quantities. They are called Neutrinos or ghost particles due to hydrogen
burning procedure ( Professor Pranab Bhattacharya & Mr. Rupak
Bhattacharyya). Conversion of hydrogen into helium in the center of the
stars or of the Sun, not only accounts for Sun’s brightness in photons of
visible light. It also produces a radiance of a more ghostly kind. The sun
glows faintly in neutrinos , which like
photons, weight nothing and travel at speed of light. Neutrinos emitted from
Sun carry an intrinsic angular momentum or spin while photons has no spin.
Matter is transparent to neutrinos which can pass effortlessly through the earth
and through the Sun. Only a tiny fraction of them is stopped by intervening
matter. As you look up our sun, a billions neutrinos pass through your eye
ball. They are not stopped by Retina as ordinary photons do ,but continue
unmolested through the back of your head. The curious part is that if at night
if I look down at ground, towards the place where sun would be, almost exactly
same numbers of solar neutrinos pass through my eye ball, pouring through an
interposed earth which is as transparent to neutrinos as a plane of clear glass
is to visible light. Neutrinos on very rare occasion convert chlorine atoms
into argon atoms with the same number of protons and neutrons. Davis
The
previous view regarding the “L atoms elements” was that each star makes it’s own share of these “L
atoms elements”i.e (autogenously origin). But the concept of autogenic view has
been now abandoned, because highest abundance values for stellar Li & Be
have shown to be not larger than interstellar upper limit. The formation of
each “L atoms” requires the acceleration of about 1erg fast proton. To account
auto genetically for lithium abundance in T. Tauri stars (L1/H=109),
the time integrated amount production of energy into particle acceleration must
be comparable with gravitational release, implying an unlikely high efficiency
for acceleration mechanism. So nuclear mechanism is responsible for
generation of “L atoms” in the star. It involves high-energy process
(Thermonuclear reactions). These L atoms” can be formed in two different
ways within the stellar interiors. By the collision of
incident light particles on the heavier atoms of interstellar gas
(For instance fast protons on stationary C, N, O) or the reverse (for
instance fast C, N, O on hydrogen at rest). In the first case the Products “ L
atoms are to remain in rest, while in the second case, the products are moving
at a velocity comparable with that of cosmic rays. The fate of “ L atoms” generated by fast protons on
stationary C, N, O stationary atoms and are all rapidly thermalised and become
part of ISM.
“L
atoms” generated by reverse process have a fate which depends on the initial
energy of “L atoms”. L atoms with energy E<0.2 Gev nucleon-1 will
stop in galactic gas (ISM) while L atoms with E > 0.3Gev neucleon-1
will suffer nuclear transformation of various elements in the stellar interior.
Analysis
of Old stars can give us some idea that heavy elements are produced in the
interior of the stars and are subsequently ejected into the ISM either through
the supernova explosion or through stellar winds or through cosmic rays. The total
mass loss, from all stars in a galaxy will be roughly 1MO per year. A fraction
of these accumulate in the galactic nuclei, which are center of the
gravitational attraction. The halo of our galaxy is nearly spherical region
containing very old stars, which have a smaller content of heavy elements than
our sun has. It is usually assumed that some how cloud of gas condensed to form
our galaxy and that the halo stars were formed during the collapse process
and left with a nearly spherical distribution. These stars are ultra high
velocity stars. These stars show weak spectral lines corresponding to abundance
of carbon and heavier elements [relative to hydrogen] that are lower than our
Sun. Because these stars are oldest in our galaxy quite distinct type of
nuclear process have been postulated for different groups of elements. The most
abundant nuclei are 32S and 58Fe those can be formed by
silicon burning process while 16O, 20Ne,23Na 24Mg,28S
may be produced by explosive carbon burning process. When heavier elements
notably Sr, Y, Zr, Ba etc require neutron capture on slow time scale, by iron
group nucleotide already present in the star. A peculiar type of star 73 DRA
has been investigated for many a time. It is full of chromium with europium and
strontium. The star showed the presence of Cr, Eu, Sr and also Mn, Fe, Ni, in
gaseous form while osmium (z=76) is present in both neutral and ionized form.
The importance of these heavy elements is that, some of them such as Iridium,
gold, uranium are also produced in the stars in the gamma process of nucleus
synthesis [Neutron capture slow process]
So Helium, L atoms, Carbon, Iron, gold,
chromium, nickel, silicon and many other elements are built up in the stellar
interior. Although the net fusing of hydrogen into helium dominates however at
this stage. Helium builds up in the core. The supply of hydrogen fuel
diminishes and eventually becomes in sufficient to provide energy to hold up
the strain position. As the energy production decreases, the core of the
star contracts and heats up through release of gravitational energy. With a
hotter center there is a greater outward pressure and the outer layer of the
star expands, so that the star now becomes a RED
GIANT. The red giant has a radius hundred times that of a sun. Mean
while in the hotter core a new series of fusion reactions begins and with the
helium as the fuel many elements like carbon oxygen, neon, magnesium. When
helium will exhaust as a fuel, the carbon burning process will start as 12C as
a fuel in the star. In any star the internal temperature and density and
therefore the rate at which the energy is generated depend sensitively on the
opacity of the stellar material or in other words, on the ease with which the
photons can escape from the stellar core. In simple terms you can say greater
the opacity harder it is for heat to get out making core hotter. Opacities in
normal star can be calculated reliably from knowledge for the abundance of the
constituent elements and their ionization site
Suernova-: Another
important thing in our universe are the supernovas or novas. The supernovas are
the explosion of the central core or outer core of a giant massive star. These
supernovas are found in the binary star system. A star may end its life cycle
either in the form of a RED GIANT or
in the form of a white dwarf or in
the form of a “ black Dwarf” or in the form of “ neutron Star” or in Black
Hole” or in the form of Supernova Explosion”.
When the explosion of a star occurs in
small scale, we call it Nova. In Big bang concept, apart from hydrogen, a
little helium was produced. Every atom of every element had been built up by
the nuclear fusion reaction in the stellar pressure cooker. The elements only
could arrive in the interstellar space
to mingle in the clouds of forming protostars is through this supernovas Novas are however quite different from
supernovas. Novas occur in binary star system and are powered by silicon or
carbon fusion. Supernovas occur in
single associated with old population II
stellar system such as elliptic galaxies and in globular clusters. The
classical supernovas are therefore a subset of the cataclysmic variable class
of objects, which undergoes out bursts with peak luminosity ~ 5x1037
to 5x 1038 ergs S-1 in every 104 to 105
years. Around 10-5 to 10-4 MO material are ejected at velocity
typically 1000 Kms-1 at each outburst of supernova. The central
system is a semi detached binary stars, containing a white dwarf . Classical
supernova out burst was observed in 1901, where as dwarf nova out burst was
first observed in 1986.
Supernovas
are two types Type-1(SN-I) and Type 2(SN_II) supernovas. Most astronomers agree that a type 1a
supernova starts with a white dwarf — an aging star that crams as much mass as
the sun into a volume no bigger than Earth. Most white dwarfs are cold and inert.
But if the star has a companion, it will siphon mass off the neighbor star
until tipping the scales at about 1.4 solar masses. At that mass, the white
dwarf becomes dense and hot enough to initiate an explosion. Mass accreting
white dwarfs, in close binary system of stars are Type-1 supernovas, while low mass (M70t <5MO) binary X ray sources
are known as Type II supernovas. Supernovas are the brightest source of
IRAS and radio noises. Supernovas are the sources of Cosmic rays also .The bulk
of the cosmic rays with high intensity are local cosmic rays and they are derived
from many such supernovas in past
distributed through our galactic disks. Historical supernovas are all too recent
and too distant , to be significant contributor of cosmic rays. In 6th April of 1947 ( almost 9 years before I was
born in this planet) a supernova, in a satellite of famous Whirlpool galaxy
called MSI was observed . A star in that galaxy
had a sudden maximum Brightness and following that within a few weeks it faded out
and had been then overlooked. A supernova appears in the spiral
galaxy on an average once in 400 years approximately. The most distant
supernova so far detected is 10 billion light years away from our earth, the first generation star it was. How much my father was correct, I often think
it today
The
remnants of the Exploding stars or supernovas are called Supernova remnants.
They are easily identified by radio astronomers up to millions years after
their explosion. The optical ultra violets and X-rays continue are produced
by the supernova explosion and interaction of the resting debris (Supernova
remnants), with dense Circumstellar gas shell, previously formed by the stellar
wind of the progenitor supernova. L. Stavely Smith , in 1992 showed the
birth of the radio noise supernova remnants SNR1987A, following radio outbursts
of Supernova 1987A[ Nature Vol-355 1992]. In the mid 1990, about 1200
earthen days after the supernova radio emission was detected at frequencies 843
MHZ and 8.6 GHG and this radio emission was within 0.5 arsc of the optical
supernovas
Although both young and old star can give rise to
supernovas, the massive stars, none of which is thought to live more than
several million years, are also thought to end their life in this way. Supernovas
can occur in conjunction with their satellite planet or binary stars. One of
You among readers of our thesis may obviously ask me that in what conditions
could a star or a planet can survive such a nearby explosion? Several
simplifying assumption can be made to answer this question.
1) The time of mass ejection will be small compared with the orbiting
period
2) The mass
of the second star or planet will be smaller than that of the pre- supernova
star. The first simplification was based on that the
ejection velocity of major fraction of the matter from a supernova will be
comparable with or larger than its initial escape velocity from the pre-
supernova star. Because the binary number is necessarily at larger radius, its
orbital velocity will be less than the average ejection velocity. If the
combined mass is reduced to less than a half by the supernova, in the limit,
where the mass ejection is sudden and where the mass of the secondary is small,
the system will un-banned regardless of the effects of the collision of the
ejected matter within the satellite of the planet.
The fractional mass ejection by supernova is
known for the thermonuclear supernova model. No remnant of star remain on the
other hand models of neutron star supernova, predicts various fractional mass
ejection depending on mass and structure of the initial star. But all the
models, be it thermonuclear or neutron star or cataclysmic variables predicts a
small fractional mass ejection, for the models slightly more massive mass than
C.S. Limit, and are self consistent, in that the mass of the remnant neutron
star does not exceed current stability limit. A star of initial mass 1.5MO leaves a remnant neutron star of mass 1MO.
The link between supernova explosion and formation of a neutron star has to be
rather established even if Type II supernovas are expected to leave to a
stellar component. Only five example of Pulsar
Supernova remnant association are known on our galaxy and in large
Megallenic cloud.
Previously as we the authors told, that mass
accreting white dwarf in close binary system can be considered to be Type-1
supernovas progenitors. Low mass (Mtot≈5MO) binary X ray sources( Known as type
II supernovas) appear to be descendents of cataclysmic variables and thus they
have been produced by collapse of a mass
accreting white dwarf. The fashionable model of explaining the out burst
involves central deflagration of a white dwarf in close binary system living no
remnant. But this model implies a unique configuration and do allow for
variation. Slow supernovas show higher peak of luminosity, higher velocity in
their ejecta and slower decline in their light curve. Fast Supernovas are
dimmer velocities of expanding material are low and light curve decay is
faster.
Super
hemps_: They are periodic increase in Brightness (up to 40%) that are
observed during occasional super out bursts lasting about 12 days, that are
additional to normal outbursts of a subclass of white dwarf Nova. Dwarf Nova’s
are characterized by two distinct class of out bursts. Normal outbursts of duration ~2 days and less
frequent super outbursts which lasts for ~12 days. During super outbursts,
super hemps are observed which modulate the visible light by≤40% with a period
3-7% longer than biniary period.
What is the Mechanism of
Explosion in Supernova
Mechanism
of Explosion in Supernova-a mechanism proposed by Professor Pranab Kumar
Bhattacharya Mr, Rupak Bhattacharya_: How much correct it is?-
What is the mechanism of a supernova
explosion in a star? It is not known yet and yet explained very well.
Possibly
one of the standard mechanisms of a supernova is the collapse& out
going shock due to collapse, leaving behind a neutron star, is the collapse of
the iron core of a massive star. During the initial
phase of the collapse, a sizable portion of the star transfers into neutrinos
with emissions of ve energy≤10Mev.[Rupak
Bhattacharya and Professor Pranab Kumar Bhattacharya’s theory] The
collapse phase lasts until the infiltrating matter becomes opaque to neutrinos.
A few~1056 ve neutrinos
are emitted during this phase. As the collapsed core reaches nuclear matter
densities, an out going shock develop. When the shock reaches the dense layer
that are still transparent to neutrinos, another ~1056V mostly Ve are expected to be emitted. The second one
of the bursts , produce neutrinos with an average energy~10Mev5~10. The whole process
lasts much less than a second. The remainder of the gravitational energy (~2x1053ergs) is emitted in the
form of vv pairs of all flavors. Although the neutron star contain vv pairs of
very high energy (100Mev), the only low energy one is eliminated, because the
neutrinos mean the free path, is strongly energy dependent. The energy is
larger for µ, e R neutrinos (Rupak neutrinos 115<Mh<127 GeV). There are dozen of neutrinos
particles of 7-35 mev mass in that energy. There charges is smaller than about
10-17 times the charge of
electron. [Such a neutrinos is R particles or R neutrinos-a near zero mass 115<Mh<127 GeV, conceptualized by Rupak Bhattacharya
as Rb+ Rb- and hence nomenclatured here according
to his name]
What is the Key thermonuclear feature of an
expanding star that will end it in supernovas? The ignition of helium in
the hydrogen as soon as exhausted, in core of a low mass star, in the presence
of a degenerate electron gas which is providing the bulk of the pressure
support of the star, the expansion of the star core starts. Because pressure of
such a gas does not increase ,substantially when temperature rises, where as
the rates of thermonuclear reaction increase dramatically with increasing
temperature, a brief run away in thermonuclear activity ensues. After this the
star in there core quickly expands. After only a small degree of nuclear
burning to an adjusted configuration, where burning can proceed in hydrostatic
equilibrium with subsequent discovery of very effective cooling of stellar
interior due to neutrinos emission, it has become apparent that intrinsically
more explosive nuclear fuel namely 12C
and16O may also ignite in
a very degenerate electron gas and that in that case, the run away in nuclear
reaction may be great enough completely to disrupt the star via a thermonuclear
explosion. The high temperature of the explosion which lasts only a fraction
of second produces such a high degree nuclear processing that expelled
thermonuclear product are vastly different than the composition of the mass
zone of the star, before the explosion. The key thermonuclear feature of
explosive burning is that several fuel combust at temperature considerably
higher than those at which same fuel burn in an object in hydrostatic
equilibrium with considerable effect in abundances of ejected matter. The over
heating may result either from the fact that the fuels first ignite in a
degenerate electron gas for the non central mass zones from the compression
heating, produced as a strong pressure and have propagation outward fro an
expanding core. In either case large amount of thermal energy are liberated in
a time short compared with star’s ability to compensate hydro dynamically, with
the result that the entire star may be given with positive energy sufficient to
disrupt it in explosion.
Before
the explosion, the gas is virtually half and consisted of 12C and 16O.
The first indication of importance of dynamics of the explosion of the final
nuclear product came in a study of carbon burning phenomenon of Arnet, who
established a numerical scheme for solving the nuclear reaction net work that
result when12C nuclear reaction began to undergo the fusion reaction
in the interior of the star before supernova[ Arnet W.D & Truran J.W
Astrophysics Jpurnal V157;P339;1969]
12C+12C 23Na+P+2.238mev 23Mg+tn -2.623mev 20 Net+α+4.616Mev
A
large numbers of computed reactions are thus possible, as the fusion reaction liberated proton, neutron,
neutrinos and alpha particles and began to react with all of the nuclear
species generated within the gas. Before the explosion, the gas is virtually
half and half of the 12C and 16O as produced in previous
epoch on helium burning plus 2% of 18O which is the result of
earlier conversion, within the same star, of all of the original CNO nuclei in
to 18O by hydrogen burning and helium burning in turn. Carbon burn
furiously for about 1/10th of
second at which time reactions are frozen by falling temperature, associated
with vigorous expansion of gas. Most of the carbon and virtually all of the
initial oxygen remain unburned, so that the final ratio of 12C/24Mg
matches the solar ratio. More subsequently the nuclei 2One,23Na, 24Mg,
26Mg,27Al, 29Si and 3O and some
time 31P are produced. So today whatever elementary nuclei we know in our earth or in earth’s atmosphere
is the fusion-burning product of a supernova explosion in a dying star.
1987
A Supernova-: and Recently detected
Supernovas[ Picture by
In
our galaxy there were evidences of eight supernovas. They are in the years
185,393,1006 AD and in 1054,1181,1572,1604,and very recently one is 1987.Only
supernovas 1006,1572,1604 were observed by European Astronomers. The
supernova of 1054 was as a cloudy patch, and remains still as Crab nebulae as
the legs of a crab. It is the remnant of that supernova. It is at a
distance of 4500 light years away and is left over gases that has a diameter of
about 6 miles. [Mitra A.K- Space Light first year 2nd
quarter1997 P10]. Supernova 1987A occurred in the large Megaloionic Cloud
(MLC).It was a supernova of a giant star SK69202 that exploded. The star was
the star of multiple star systems instead of a binary star system. SN 1987a was 18 solar mass blue giant Sanduleak
-69° 202a, a mere 0.000168 billion light-years distant. This star
had lost a considerable mass of M20O due to the explosion. The other
members of this giant multiple system is now visible as supernova remnant. The
SK 69202 was probably a red super giant 104—105 years ago.
The outer envelop, blue star giant progenitor star is preserved during the
rapid supersonic un turbulence outflow of the supernova. The huge amount of R-
neutrinos (Rupak Particles) are now emitted by this 1987A supernova proposes
the formation of a neutron star, inside this supernova some have reported
that central region of this supernova was a central pulsar. However the
history of this supernova 1987A is today 23 years old. In the supernova 1987A
there is evidence of presence of H3+ in the envelope or in the shell
of it. The infrared L window spectrum of supernova 1987A is between 2.95-4.15um
were obtained by hydrogen re combination line ( Mcikle.W. PS Not.R. Astr
Society V283;P193-223;1989). But from 110 days onward there were an
evidence of hydrogen recombination line between spectrum 3.41-3.53um. These
were possibilities in wave length at which H3+ announces most strongly presence
of a planet like Jupiter (Okata.T etal- Astrophysics J-Vol351;P253-56;1990).When
the first explosion of supernova 1987A happened there were a brief initial
outburst of radio emissions that lasted for more than a few days. The expanding
Nebulae were set into motion by the ejection and cooling of ejected material
and its interaction with circumstellar material that surrounded the
progenitor& was then non visible at the available radio frequencies.
Evolution of radio-supernova remnant over the last years provided us the
information about the progress of the expanding supernova remnant. The nature
of its unusual progenitor star which was first a red
giant and then a blue giant, before it exploded. In the red giant phase, the
star threw off a dense slow moving wind which was succeeded by a more tenuous
but faster wind from the blue giant. The circumstellar material of the
progenitor at the moment of the explosion there fore consisted of a hot thin
gas- cocooned inside a cooler thicker shell with a supersonic shock wave
created at the boundary, as the blue giant
wind ran into red giant wind. The first brief flash of radio emission was a
very minor part of the initial supernova outbursts and was probably
attributable to the propagation of shock wave from explosion through the thin
material immediately surrounding what had been progenitor star.
Supernova are now routinely observed in other
galaxies . During the life time of a galaxy about 10 billion years, a hundred
millions of stars exploded. Amongst them, David Helfend and Knoxlong reported
an extremely intense burst of hard X-ray and gamma rays which was also recorded
by nine interplanetary space crafts and which was also probably Supernova N49
remnant in large Megellanic Cloud [ MLC is a small satellite galaxy of Milky
Way 18,0000 light year distant)[ Nature march5,1979 & decemb6 1979]. The
recent nova which had been detected in Cygx-1 galaxy. It was Nova V404 cygni-
Low mass x ray binary emits x ray and x ray behavior is similar to black hole
system. In April 6,1947 discovered a supernova in a satellite of famous
whirlpool galaxy M51- A star suddenly had maximum brightness and had then
overlooked. On 9th January 2008, while viewing of galaxy NGC 2770 an unexpected
transient burst of Xray was detected in one of the galaxies spiral arm. Further
observation showed that the burst was a first sighting of new type of Ibc
supernova duly was named as SN200D. Most distant Supernovae are super bright, and that makes them easy to
see from far away. Very far away. 11 Billion Light years to be exact from
earth. almost at time of birth of first generation stars and galaxy.
Pulsar formation is generally attributed to
supernova events and two pulsars are till associated with known supernova
events. They are Crab Nebulae pulsar NP0532 and Vela. Other pulsars are close
enough to supernova remnants to suggest an association but only if they are
moving away from the remnants at velocities of order 103 Km/second.
Fowler KA and Hogel F in 1963 suggested that supernova core may well be too
massive to form a gravitationally stable
object(neutron Star) and gravitationally Collapsing Object(black Hole too).
They suggested that systemic ejection of Radio luminous material from galaxy
could be caused by symmetrical process occurring in the collapse of very
massive objects, thus the more massive core could fission into several less
massive objects. The same process can be applied to supernova events where core
fragments into some distribution of neutron stars” Black holes’ and general
debris[ Fowler WA, Hoyel F Nature 197; 533;1963]. There is a pulsar PSR 1509-58
located near the center of radio supernova remnant MSH 15-52, a supernova
remnant of supernova AD1054. This pulsar is young only about 1700 years. The
near coincidence of this age with that of supernova of AD 185 strongly suggest
that PSR1509-58 was born in AD1054 supernova explosion.
Why Supernovae? – the new measure of the Universe When Einstein got rid of the cosmological
constant and surrendered to the idea of a non-static Universe, he related the
geometrical shape of the Universe to its fate. Is it open or closed, or is it
something in between – a flat Universe? An open Universe is one where the
gravitational force of matter is not large enough to prevent the expansion of
the Universe. All matter is then diluted in an ever larger, ever colder and
ever emptier space. In a closed Universe, on the other hand, the gravitational
force is strong enough to halt and even reverse the expansion. So the Universe
eventually would stop expanding and fall back together in a hot and violent
ending, a Big Crunch.
Most cosmologists, and I myself however, would prefer to live in the
most simple and mathematically elegant Universe: a flat one, where the
expansion is believed to decline. The Universe would thus end neither in fire
nor in ice. But there is no choice left by laws of the Universe. If there is a
cosmological constant, the expansion will continue to accelerate, even if the
Universe is flat.2011 Physics Nobel Laureates expected to measure the cosmic
deceleration, or how the expansion of the Universe is slowing. Their method
was in principle the same as the one used by astronomers more than six decades
earlier: to locate distant stars and to measure how they move. However, that is
easier said than done. Since Henrietta Leavitt’s days many other Cepheids have
been found that are even farther away. But at the distances that astronomers
need to see, billions of light years away, Cepheids are no longer visible. The
cosmic yardstick needed to be extended. Supernovae
– star explosions – became the new standard candles. More sophisticated
telescopes on the ground and in space, as well as more powerful computers,
opened the possibility in the 1990s to add more pieces to the cosmological
puzzle. Crucial were the light-sensitive digital imaging sensors –
charged-coupled devices or CCD – the invention by Willard
Boyle and George Smith who were
awarded Nobel Prize in Physics in 2009. White dwarfs exploding
the newest tool in the astronomer’s toolbox is a special kind of
star explosion, the type Ia
supernova. During a few weeks, a single such supernova can emit as
much light as an entire galaxy. This type of supernova is the explosion of an
extremely compact old star that is as heavy as the Sun but as small as the
Earth – a white dwarf. The explosion is the final step in the white
dwarf’s life cycle. White dwarfs form when a star has no more energy at its
core, as all hydrogen and helium have been burned in nuclear reactions. Only
carbon and oxygen remain. In the same way, far off in the future, our Sun will fade and cool down as it reaches its end as a white
dwarf. A far more
exciting end awaits a white dwarf that is part of a
binary star system, which is fairly common. In this case, the white dwarf’s strong gravity robs the
companion star of its gas. However, when the white dwarf has grown to 1.4 solar
masses, it no longer
The nuclear fusion products emit strong radiation that increases rapidly during
the first weeks after the explosion, only to decrease over the following
months. So there is a rush to find supernovae – their violent explosions are
brief. Across the visible Universe, about ten type Ia supernovae occur every
minute. But the Universe is huge. In a typical galaxy only one or two supernova
explosions occur in a thousand years. In September 2011, we were lucky to
observe one such supernova in a galaxy close to the Big Dipper, visible just
through a pair of regular binoculars. But most supernovae are much farther away
and thus dimmer. So where and when would you look in the canopy of the sky? manages to hold together. When this
happens, the interior of the dwarf becomes sufficiently hot for runaway fusion
reactions to start, and the star gets ripped apart in seconds.
From the planet the earth here towards eternity?
So what is it that is speeding
up the Universe? It is called dark energy and is still probably a
challenge for particle physics, a riddle, that no one has managed to solve yet
of what it is composed of. Several ideas have been however proposed.
Within the framework
of the standard cosmological model, the acceleration is generally believed to
be caused by the vacuum energy (sometimes called ”dark energy”) which – based
on concordant data from the S Ne, the observations of the anisotropies in the
CMB and surveys of the clustering of galaxies – accounts for about 73% of the
total energy density of the Universe. Of the remainder, about 23% is due to an
unknown form of matter (called ”dark matter”).
Only about 4% of the energy density corresponds to ordinary matter like
atoms in everyday life, the
effects of the vacuum energy are tiny but measurable – observed for instance in
the form of shifts of the energy levels
of the hydrogen atom, the Lamb shift. The evolution of the Universe is
described by Einstein’s theory of general relativity. In relativistic field
theories, the vacuum energy contribution is given by an expression
mathematically similar to the famous cosmological constant in Einstein’s theory. Our question is so question of whether the vacuum energy term is truly time independent
like the cosmological constant, or varies with time,.
The simplest is to
reintroduce Einstein’s cosmological constant, which he once rejected. At that
time, he inserted the cosmological constant as an anti-gravitational force to
counter the gravitational force of matter and thus create a static Universe.
Today, the cosmological constant instead appears to make the expansion of the
Universe to accelerate. The cosmological constant is, of course, constant, and
as such does not change over time. So dark
energy becomes dominant when matter, and thus its gravity, gets diluted due to
expansion of the Universe over billions of years. According to scientists, that
would account for why the cosmological constant entered the scene so late in
the history of the Universe, only five to six billion years ago. At about that
time, the gravitational force of matter had weakened enough in relation to the
cosmological constant. Until then, the expansion of the Universe had been
decelerating.
The cosmological constant could have its
source in the vacuum, empty space that, according to quantum physics, is never
completely empty. Instead, the
vacuum is a bubbling quantum soup where virtual particles of matter and
antimatter pop in and out of existence and give rise to energy. However,
the simplest estimation for the amount of dark energy does not correspond at
all to the amount that has been measured in space, which is about 10120
times
larger (1 followed by 120 zeros). This constitutes a gigantic and still unexplained
gap between theory and observation – on all the sea beaches of the world there
are no more than 1020 (1 followed by
20 zeros) grains of sand. It may be that the dark energy is not constant after
all. Perhaps it changes over time. Perhaps an unknown force field only
occasionally generates dark energy. In physics there are many such force fields
that collectively go by the name quintessence, after the Greek name for
the fifth element. Quintessence could speed up the Universe, but only
sometimes. That would make it impossible to foresee the fate of the Universe.
Whatever dark energy is, it seems to be here to stay. It fits very well in the
cosmological puzzle that physicists and astronomers have been working on for a
long time. According to current consensus, about three quarters of the Universe
consist of dark energy. The rest is matter. But the regular matter, the stuff
that galaxies, stars, humans and flowers are made of, is only five percent of
the Universe. The remaining matter is called dark matter and is so far
hidden from us. The dark matter is yet another mystery in our largely unknown
cosmos. Like dark energy, dark matter is invisible. So we know both only by
their effects – one is pushing, the other one is pulling. They only have the
adjective “dark” in common.[2]
The study of distant
supernovae according to us authors may constitutes a crucial contribution to
cosmology. Together with galaxy clustering and the CMB anisotropy measurements, it allows precise determination of
cosmological parameters. The observations present us with a challenge, however:
What is the source of the dark
energy that drives the accelerating
expansion of the Universe? Or is our understanding of gravity as described by
general relativity insufficient? Or was
Einstein’s “mistake” of introducing
the cosmological constant one more stroke of his genius? Many new
experimental efforts are underway to help shed light on these questions.
So Our Questions to readers of my blogs
1] Universe has been
expanding; like raisins in a raisin cake swelling in the oven, But No body
still answered what is beyond that Planck’s moment of Big Bang Creation of our
universe. Was there another universe? Was there multiple Universe? Or Multi
electrical universe?—
2] Question
Yet remains to us how these supernovas explode? What is the
mechanism behind it? No physics probably
answered it yet. Here may be some explanations by my brothers Rupak
Bhattacharya and Ritwik Bhattacharya the
authors— Our Question No –(2)
What is the
Mechanism of Explosion in Supernova
( our Question NO-3)
Mechanism of Explosion in Supernova-a
mechanism proposed by Professor Pranab Kumar Bhattacharya Mr, Rupak Bhattacharya_: How much correct it is
3] So what is it that is speeding up the Universe? It is called dark energy and is still a challenge
for physics, a riddle, that no one has managed to solve yet of what it is
composed of
4] . Our question is question of whether the vacuum energy term is truly time
independent like the cosmological constant, or varies with time,.
Do you know the answer? If yes please contact
References
1]”
Did our universe started in a Big Bang gospel or Just Be?” Authors: Professor
Pranab Kumar Bhattacharya, Mr. Rupak Bhattacharya, Mr. Ritwik Bhattacharya Mrs. Dalia Mukherjee & Miss Upasana
Bhattacharya in the chapter” Fate of a Star” once published at www.unipathos.com as E book in July 2004.
The Website www.unipathos.com had been surrendered to star Dust Company in
2010 and the same E book No more available there.
2]
“Written in the stars”: THE NOBEL
PRIZE IN PHYSICS 2011
INFORMATION FOR THE PUBLIC
published in www.nobelprize.org
By Science Editors Lars Bergström, Olga Botner, Lars Brink, Börje Johansson, The
Nobel Committee for Physics/The Royal
Swedish Academy of SciencesEditor: Annika Moberg The Royal
Swedish Academy of Sciences THE NOBEL PRIZE IN PHYSICS
2011 THE ROYAL SWEDISH ACADEMY
Links
to see other sites?
1] Runaway
Universe, www.pbs.org/wgbh/nova/universe/
2] Appell,
D. (2008) Dark Forces at Work, Scientific American,
Acknowledgement
& Tribute -
To our diseased parent late Mr. Bholanath Bhattacharya B.com(Calcutta Univ)
FCA(Ind.) SAS and late Mrs Bani
Bhattacharya of residence 7/51 Purbapalli, Po-Sodepur, Dist 24 parganas (north)
, Kolkata-110,WestBengal, India, for
their initial teaching for us about the
Universe, Big Bang and eternity
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