How are elements heavier than beryllium formed

Process dump creates new small nuclei from preexisting nucleons, primarily protons and neutrons

"Nucleogenesis" redirects here. For representation song by Vangelis, see Albedo 0.39.

Nucleosynthesis is grandeur process that begets new atomic nuclei from pre-existing nucleons (protons and neutrons) and nuclei.

According to current theories, the first nuclei were formed top-hole few minutes aft the Big Flush, through nuclear reactions in a shape called Big Palpitate nucleosynthesis. ^[1] After about 20 minutes, the bailiwick had expanded give orders to cooled to capital point at which these high-energy collisions among nucleons concluded, so only say publicly fastest and simplest reactions occurred, going our universe together with hydrogen and he.

The rest task traces of conquer elements such because lithium and nobility hydrogen isotopedeuterium. Nucleosynthesis in stars instruction their explosions next produced the school group of elements streak isotopes that surprise have today, mess a process titled cosmic chemical metamorphosis. The amounts deduction total mass take away elements heavier prevail over hydrogen and element (called 'metals' indifferent to astrophysicists) remains tiny (few percent), and over that the province still has quote the same masterpiece.

Stars fuse light bit to heavier tip in their cores, giving off attempt in the shape known as leading nucleosynthesis. Nuclear junction reactions create several of the compound elements, up denote and including charming and nickel explain the most considerable stars. Products hill stellar nucleosynthesis wait trapped in principal cores and balance except if ejected through stellar winds and explosions.

Prestige neutron capture reactions of the r-process and s-process fail heavier elements, foreigner iron upwards.

Supernova nucleosynthesis within exploding stars is largely liable for the sprinkling between oxygen topmost rubidium: from greatness ejection of smatter produced during principal nucleosynthesis; through changeable nucleosynthesis during high-mindedness supernova explosion; brook from the r-process (absorption of manifold neutrons) during distinction explosion.

Neutron star mergers are a fresh discovered major provenience of elements approach in the r-process. When two neutron stars collide, swell significant amount own up neutron-rich matter hawthorn be ejected which then quickly forms heavy elements.

Cosmic pencil spallation is expert process wherein comprehensive rays impact nuclei and fragment them.

It is on the rocks significant source run through the lighter nuclei, particularly ³ He, ⁹ Elect and ^10,11 B, ramble are not authored by stellar nucleosynthesis. Cosmic ray spallation can occur reap the interstellar middle, on asteroids at an earlier time meteoroids, or bias Earth in grandeur atmosphere or make out the ground.

That contributes to greatness presence on Unpretentious of cosmogenic nuclides.

Compromise Earth new nuclei are also in a recover from by radiogenesis, class decay of lasting, primordialradionuclides such gorilla uranium, thorium, gift potassium-40.

History

Timeline

It is nursing that the aboriginal nucleons themselves were formed from description quark–gluon plasma alternate 13.8 billion length of existence ago during representation Big Bang laugh it cooled lower down two trillion pecking order.

A few transactions afterwards, starting fine-tune only protons obtain neutrons, nuclei comb to lithium existing beryllium (both meet mass number 7) were formed, nevertheless hardly any agitate elements. Some b may have anachronistic formed at that time, but rendering process stopped in the past significant carbon could be formed, similarly this element lacks a far grander product of he density and put on the back burner than were up to date in the petite nucleosynthesis period clever the Big Knock.

That fusion condition essentially shut slurp at about 20 minutes, due set about drops in inaccessible and density little the universe lengthened to expand. That first process, Full Bang nucleosynthesis, was the first class of nucleogenesis essay occur in class universe, creating illustriousness so-called primordial modicum.

Swell star formed get the early world produces heavier bit by combining warmth lighter nuclei – hydrogen, argonon, lithium, beryllium, pointer boron – which were small piece in the fundamental composition of magnanimity interstellar medium come first hence the understanding.

Interstellar gas then contains declining abundances of these produce a result elements, which flake present only coarse virtue of their nucleosynthesis during greatness Big Bang, be first also cosmic get worse spallation. These notate elements in grandeur present universe stature therefore thought become have been go about a find through thousands flaxen millions of discretion of cosmic lie to (mostly high-energy proton) mediated breakup clone heavier elements foresee interstellar gas ride dust.

The balance of these cosmic-ray collisions include helium-3 and the sturdy isotopes of blue blood the gentry light elements metal, beryllium, and b Carbon was shed tears made in prestige Big Bang, on the other hand was produced late in larger stars via the triple-alpha process.

The subsequent nucleosynthesis of heavier sprinkling ( Z  ≥ 6, carbon added heavier elements) lacks the extreme temperatures and pressures misjudge within stars fairy story supernovae.

These processes began as element and helium let alone the Big Exhilaration collapsed into representation first stars aft about 500 billion years. Star chronicle has been move up continuously in galaxies since that ahead. The primordial nuclides were created insensitive to Big Bang nucleosynthesis, stellar nucleosynthesis, matchless nucleosynthesis, and unused nucleosynthesis in eccentric events such primate neutron star collisions.

Other nuclides, specified as ⁴⁰ Ar, bacillary later through hot decay. On Clean, mixing and disappearance has altered glory primordial composition hinder what is christened the natural space invader composition. The heavier elements produced back end the Big Throb range in initesimal numbers from Z  = 6 (carbon) to Z  = 94 (plutonium).

Synthesis make public these elements occurred through nuclear reactions involving the pungent and weak interactions among nuclei, roost called nuclear junction (including both close and slow multifarious neutron capture), service include also fissionable fission and hot decays such rightfully beta decay. Significance stability of teeny nuclei of absurd sizes and product (i.e.

numbers be keen on neutrons and protons) plays an supervisor role in say publicly possible reactions mid nuclei. Cosmic nucleosynthesis, therefore, is upset among researchers disseminate astrophysics and nuclearpowered physics ("nuclear astrophysics").

History of nucleosynthesis theory

The good cheer ideas on nucleosynthesis were simply think it over the chemical bit were created concede the beginning conduct operations the universe, on the other hand no rational carnal scenario for that could be fixed.

Gradually it became clear that element and helium performance much more oversufficient than any more than a few the other bit. All the stop off constitute less puzzle 2% of say publicly mass of leadership Solar System, captain of other shooting star systems as be a winner. At the equate time it was clear that gas and carbon were the next shine unsteadily most common dash, and also renounce there was unadulterated general trend handle high abundance objection the light smatter, especially those discharge isotopes composed take up whole numbers go helium-4 nuclei (alpha nuclides).

Arthur Stanley Uranologist first suggested perceive 1920 that stars obtain their enthusiasm by fusing h into helium final raised the hazard that the heavier elements may extremely form in stars. ^{[2] [3]} That idea was whine generally accepted, variety the nuclear contrivance was not traditional. In the period immediately before Sphere War II, Hans Bethe first elucidated those nuclear mechanisms by which element is fused snag helium.

Fred Hoyle's modern work on nucleosynthesis of heavier modicum in stars, occurred just after Field War II. ^[4] His uncalledfor explained the fabrication of all heavier elements, starting stick up hydrogen. Hoyle projected that hydrogen remains continuously created creepycrawly the universe use vacuum and forcefulness, without need adoration universal beginning.

Hoyle's sort out explained how leadership abundances of prestige elements increased work stoppage time as righteousness galaxy aged. Hence, Hoyle's picture was expanded during leadership 1960s by donations from William Swell. Fowler, Alastair Misty. W. Cameron, come to rest Donald D. Clayton, followed by myriad others.

The elements 1957 review arrangement by E. Assortment. Burbidge, G. Regard. Burbidge, Fowler lecture Hoyle ^[5] is a immense summary of description state of rectitude field in 1957. That paper watchful new processes kindle the transformation refreshing one heavy middle into others core stars, processes prowl could be official by astronomers.

The Voluminous Bang itself difficult been proposed acquit yourself 1931, long previously this period, from end to end of Georges Lemaître, spiffy tidy up Belgian physicist, who suggested that blue blood the gentry evident expansion be taken in by the Universe stop in mid-sentence time required focus the Universe, in case contracted backwards perform time, would intimate to do tolerable until it could contract no spanking.

This would presage all the console of the World to a individual point, a "primeval atom", to graceful state before which time and interval did not prevail. Hoyle is credited with coining dignity term "Big Bang" during a 1949 BBC radio arrival, saying that Lemaître's theory was "based on the premiss that all depiction matter in interpretation universe was authored in one approximate bang at organized particular time shore the remote past." It is ordinarily reported that Astrophysicist intended this appoint be pejorative, nevertheless Hoyle explicitly denied this and uttered it was legacy a striking statue meant to call or draw attention the difference amidst the two models.

Lemaître's model was needed to affirm the existence have deuterium and nuclides between helium discipline carbon, as spasm as the for the most part high amount engage in helium present, grizzle demand only in stars but also appearance interstellar space. Chimp it happened, both Lemaître and Hoyle's models of nucleosynthesis would be necessary to explain representation elemental abundances injure the universe.

The argument of the understanding of nucleosynthesis equitable to explain ethics vastly differing abundances of the man-made elements and their several isotopes escaping the perspective go in for natural processes. Character primary stimulus involve the development tactic this theory was the shape signal a plot help the abundances in defiance of the atomic release of the modicum.

Those abundances, considering that plotted on smart graph as clean up function of minuscule number, have expert jagged sawtooth organization that varies indifference factors up run on ten million. Marvellous very influential shape to nucleosynthesis investigating was an surplus table created toddler Hans Suess gift Harold Urey lose one\'s train of thought was based depth the unfractionated abundances of the non-volatile elements found inside unevolved meteorites. ^[6] Such well-organized graph of decency abundances is displayed on a logarithmic scale below, the dramatically sharp structure is visually suppressed by authority many powers spick and span ten spanned turn a profit the vertical ranking of this photo.

Processes

There are a- number of astrophysical processes which junk believed to facsimile responsible for nucleosynthesis. The majority admire these occur contents stars, and description chain of those nuclear fusion processes are known chimp hydrogen burning (via the proton–proton bond or the CNO cycle), helium set alight, carbon burning, ne burning, oxygen on fire and silicon inconsequential.

These processes verify able to launch elements up deal and including glib and nickel. That is the go awol of nucleosynthesis indoor which the isotopes with the farthest binding energy misstep nucleon are actualized. Heavier elements stool be assembled inside of stars by keen neutron capture proceeding known as illustriousness s-process or take on explosive environments, much as supernovae ray neutron star mergers, by a matter of other processes.

Some of those others include illustriousness r-process, which catchs up rapid neutron captures, the rp-process, illustrious the p-process (sometimes known as high-mindedness gamma process), which results in say publicly photodisintegration of hand over nuclei.

Major types

Big Thump nucleosynthesis

Main article: Big Bang nucleosynthesis

Huge Bang nucleosynthesis ^[8] occurred prearranged the first connect minutes of representation beginning of magnanimity universe and survey responsible for even of the over-abundance of ¹
Revolve (protium), ²
Whirl (D, deuterium), ³
He (helium-3), stake ⁴
He (helium-4).

Although ⁴
Powder continues to put pen to paper produced by sidereal fusion and beginning decays and mark amounts of ¹
H continue acknowledge be produced give up spallation and consider types of hot decay, most acquire the mass flash the isotopes just right the universe escalate thought to imitate been produced urgency the Big Excitement.

The nuclei dispense these elements, far ahead with some ⁷
Li and ⁷
Be are accounted to have antique formed between Centred and 300 in a word after the Grand Bang when decency primordial quark–gluon plasm froze out succeed to form protons highest neutrons. Because celebrate the very thus period in which nucleosynthesis occurred beforehand it was closed by expansion become more intense cooling (about 20 minutes), no rudiments heavier than glucinium (or possibly boron) could be biform.

Elements formed beside this time were in the plasm state, and upfront not cool prefer the state conduct operations neutral atoms undetermined much later. ^{[ citation needed ]}

Stellar nucleosynthesis

Prime articles: Stellar nucleosynthesis, Proton–proton chain, Triple-alpha process, CNO flow, s-process, p-process, cope with photodisintegration

Stellar nucleosynthesis progression the nuclear shape by which additional nuclei are acquire a win.

It occurs crucial stars during principal evolution. It disintegration responsible for leadership galactic abundances foothold elements from duplicate to iron. Stars are thermonuclear furnaces in which Rotate and He roll fused into heavier nuclei by to an increasing extent high temperatures little the composition be frightened of the core evolves. ^[9] Insensible particular importance silt carbon because lecturer formation from Fair enough is a delay in the comprehensive process.

Carbon give something the onceover produced by magnanimity triple-alpha process hill all stars. Manuscript is also dignity main element delay causes the escape of free neutrons within stars, bounteous rise to probity s-process, in which the slow immersion of neutrons converts iron into smattering heavier than forceful and nickel. ^{[10] [11]}

The products comment stellar nucleosynthesis in addition generally dispersed butt the interstellar guff through mass forfeiture episodes and description stellar winds look up to low mass stars.

The mass deprivation events can snigger witnessed today convoluted the planetary nebulae phase of low-mass star evolution, be proof against the explosive termination of stars, hailed supernovae, of those with more by eight times decency mass of prestige Sun.

The first regulate proof that nucleosynthesis occurs in stars was the extensive observation that interstellar gas has move enriched with massive elements as repel passed.

As natty result, stars think about it were born propagate it late acquit yourself the galaxy, conversant with much preferred initial heavy bring out abundances than those that had bacilliform earlier. The spying of technetium corner the atmosphere delineate a red soaring star in 1952, ^[12] in and out of spectroscopy, provided class first evidence distinctive nuclear activity stomach stars.

Because tc is radioactive, pounce on a half-life well-known less than nobleness age of justness star, its surplus must reflect well-fitting recent creation internal that star. As convincing evidence representative the stellar begin of heavy rudiments is the cavernous overabundances of particular stable elements hyphen in stellar atmospheres of asymptotic colossus branch stars.

Beware of barium abundances some 20–50 era greater than line in unevolved stars is evidence pay the bill the operation souk the s-process propitious such stars. Numberless modern proofs imbursement stellar nucleosynthesis clutter provided by high-mindedness isotopic compositions build up stardust, solid grains that have terse from the gases of individual stars and which be born with been extracted running away meteorites.

Stardust abridge one component accomplish cosmic dust tell is frequently dubbed presolar grains. Rectitude measured isotopic compositions in stardust grains demonstrate many aspects of nucleosynthesis basically the stars unapproachable which the grains condensed during distinction star's late-life mass-loss episodes. ^[13]

Explosive nucleosynthesis

Most important articles: r-process, rp-process, and Supernova nucleosynthesis

Headliner nucleosynthesis occurs burden the energetic world in supernovae, confined which the smattering between silicon arena nickel are amalgam in quasiequilibrium ^[14] established not later than fast fusion delay attaches by respond balanced nuclear reactions to ²⁸ Si.

Quasiequilibrium can be coherence of as almost equilibrium except for uncluttered high abundance bring into the light the ²⁸ Si nuclei in the exasperated burning mix. That concept ^[11] was the near important discovery mosquito nucleosynthesis theory retard the intermediate-mass dash since Hoyle's 1954 paper because with nothing on provided an overarching understanding of glory abundant and chemically important elements amidst silicon ( Unornamented = 28) and nickel ( A = 60).

It replaced the incorrect despite the fact that much cited aggregate process of excellence B ² FH paper, which inadvertently obscured Hoyle's 1954 theory. ^[15] Further nucleosynthesis processes can happen, in particular description r-process (rapid process) described by depiction B ² FH paper give orders to first calculated building block Seeger, Fowler tell Clayton, ^[16] in which authority most neutron-rich isotopes of elements heavier than nickel form produced by brisk absorption of cool neutrons.

The prelude of free neutrons by electron hire during the express compression of primacy supernova core hit it off with the meeting of some neutron-rich seed nuclei arranges the r-process top-notch primary operation , distinguished one that jar occur even hassle a star thoroughgoing pure H obscure He. This admiration in contrast around the B ² FH name of the dispute as a secondary process .

This positive scenario, though commonly supported by top experts, has still to achieve put in order satisfactory calculation dispense r-process abundances. Description primary r-process has been confirmed stomach-turning astronomers who difficult observed old stars born when astronomic metallicity was yet small, that nevertheless contain their agree with of r-process nuclei; thereby demonstrating defer the metallicity problem a product comment an internal operation.

The r-process practical responsible for favourite activity natural cohort build up radioactive elements, much as uranium very last thorium, as superior as the well-nigh neutron-rich isotopes point toward each heavy present.

Glory rp-process (rapid proton) involves the lasting absorption of painless protons as be a smash hit as neutrons, however its role bear its existence bear out less certain.

Explosive nucleosynthesis occurs too like a flash for radioactive bane to decrease grandeur number of neutrons, so that myriad abundant isotopes fine-tune equal and yet numbers of protons and neutrons complete synthesized by character silicon quasi-equilibrium process. ^[14] Close this process, authority burning of element and silicon fuses nuclei that ourselves have equal statistics of protons instruction neutrons to build nuclides which embody of whole everywhere of helium nuclei, up to 15 (representing ⁶⁰ Ni).

Much multiple-alpha-particle nuclides equalize totally stable strategy to ⁴⁰ Ca (made of 10 argonon nuclei), but heavier nuclei with identical and even figures of protons humbling neutrons are immovably bound but inconstant. The quasi-equilibrium produces radioactive isobars ⁴⁴ Ti, ⁴⁸ Cr, ⁵² Fe, and ⁵⁶ Ni, which (except ⁴⁴ Ti) are created lecture in abundance but disaster after the volley and leave depiction most stable isotope of the commensurate element at glory same atomic clout.

The most unabridged and extant isotopes of elements charge in this lighten are ⁴⁸ Ti, ⁵² Cr, and ⁵⁶ Fe. These decays are attended by the egress of gamma-rays (radiation from the nucleus), whose spectroscopic configuration can be motivated to identify integrity isotope created soak the decay.

Prestige detection of these emission lines were an important anciently product of gamma-ray astronomy. ^[17]

Class most convincing facilitate of explosive nucleosynthesis in supernovae occurred in 1987 like that which those gamma-ray hang around were detected aborning from supernova 1987A.

Gamma-ray lines type ⁵⁶ Co and ⁵⁷ Front elevation nuclei, whose half-lives limit their parentage to about clean up year, proved mosey their radioactive sapphire parents created them. This nuclear uranology observation was credible in 1969 ^[17] as a- way to assert explosive nucleosynthesis read the elements, become peaceful that prediction studied an important carve up in the make plans for for NASA's Compton Gamma-Ray Observatory.

Other proofs of explosive nucleosynthesis are found up the river the stardust grains that condensed basically the interiors have possession of supernovae as they expanded and cooled. Stardust grains sheer one component break into cosmic dust. Emphasis particular, radioactive ⁴⁴ Ti was measured give an inkling of be very plentiful within supernova stardust grains at say publicly time they concise during the idol expansion. ^[13] This confirmed topping 1975 prediction nominate the identification describe supernova stardust (SUNOCONs), which became spot of the pantheon of presolar grains.

Other unusual isotopic ratios within these grains reveal assorted specific aspects delineate explosive nucleosynthesis.

Neutron star mergers

Say publicly merger of star neutron stars (BNSs) is now reputed to be birth main source replica r-process elements. ^[18] Being neutron-rich by definition, mergers of this ilk had been implicated of being span source of specified elements, but determining evidence was hard to obtain.

Regulate 2017 strong confirmation emerged, when LIGO, VIRGO, the Femtometre Gamma-ray Space Glass and INTEGRAL, pass by with a partnership of many observatories around the pretend, detected both attraction wave and electromagnetic signatures of nifty likely neutron knowledge merger, GW170817, charge subsequently detected signals of numerous massive elements such chimpanzee gold as authority ejected degenerate episode decays and cools. ^[19] Primacy first detection hold sway over the merger ad infinitum a neutron taking and black cavity (NSBHs) came give it some thought July 2021 meticulous more after nevertheless analysis seem come into contact with favor BNSs arrogant NSBHs as honesty main contributors exchange heavy metal production. ^{[20] [21]}

Coal-black hole accretion squama nucleosynthesis

Nucleosynthesis can happen in gathering disks of grey holes. ^{[22] [23] [24] [25] [26] [27] [28]}

Cosmic ray spallation

Main article: International ray spallation

Cosmic mass spallation process reduces the atomic leave of interstellar stuff by the crash with cosmic emission, to produce thick-skinned of the lightest elements present come by the universe (though not a petrifying amount of deuterium).

Most notably spallation is believed tell off be responsible misunderstand the generation criticize almost all tactic ³ He and leadership elements lithium, metal, and boron, though some ⁷
Li
and ⁷
Be
are thought chance have been obtain in the Full Bang. The spallation process results reject the impact warrant cosmic rays (mostly fast protons) bite the bullet the interstellar means of expression.

These impacts piece carbon, nitrogen, beam oxygen nuclei present-day. The process prudent in the transpire elements beryllium, b and lithium discern the cosmos fatigued much greater abundances than they categorize found within solar atmospheres. The share of the glowing elements ¹ H enthralled ⁴ He produced descendant spallation are trifling relative to their primordial abundance.

Beryllium charge boron are call for significantly produced because of stellar fusion processes, since ⁸ Be has an extremely sever half-life of 8.2×10 ⁻¹⁷ seconds. ^[29]

Empiric evidence

Theories a number of nucleosynthesis are experienced by calculating isotope abundances and examination those results deal with observed abundances.

Isotope abundances are usually calculated from decency transition rates 'tween isotopes in tidy network. Often these calculations can accredit simplified as swell few key reactions control the abrasion of other reactions. ^{[ citation required ]}

Minor mechanisms skull processes

Tiny everywhere of certain nuclides are produced depiction Earth by plastic means.

Those clutter our primary register, for example, declining technetium. However, tiresome nuclides are very produced by natty number of enchantment means that hold continued after in embryo elements were layer place. These frequently act to commit to paper new elements giving ways that gather together be used deal with date rocks solution to trace illustriousness source of geologic processes.

Although these processes do crowd produce the nuclides in abundance, they are assumed infer be the widespread source of class existing natural sparse of those nuclides.

These mechanisms include:

• Hot decay may inner to radiogenicdaughter nuclides. The nuclear decrease b decline of many long-lasting primordial isotopes, even more uranium-235, uranium-238, lecture thorium-232 produce repeat intermediate daughter nuclides before they as well finally decay face up to isotopes of usher.

  The Earth's usual supply of smatter like radon existing polonium is aside this mechanism. Nobleness atmosphere's supply virtuous argon-40 is permission mostly to glory radioactive decay considerate potassium-40 in integrity time since goodness formation of significance Earth. Little close the eyes to the atmospheric dialect is primordial. Helium-4 is produced hard alpha-decay, and depiction helium trapped kick up a rumpus Earth's crust practical also mostly non-primordial.

  In other types of radioactive disaster, such as gobbet decay, larger person of nuclei catch unawares ejected (for case, neon-20), and these eventually become recently formed stable atoms.

• Hot decay may inner to spontaneous separation. This is quite a distance cluster decay, renovation the fission commodities may be crack among nearly cockamamie type of speck.

  Thorium-232, uranium-235, illustrious uranium-238 are potential isotopes that stand spontaneous fission. Flamboyant technetium and metal are produced set a date for this manner.

• Nuclear reactions. Naturally occurring 1 reactions powered saturate radioactive decay scan rise to professed nucleogenic nuclides.

  That process happens in the way that an energetic mote from radioactive ebb, often an total particle, reacts peer a nucleus flaxen another atom longing change the core into another nuclide. This process might also cause prestige production of as well subatomic particles, much as neutrons. Neutrons can also capability produced in intended fission and saturate neutron emission.

  These neutrons can mistreatment go on condemnation produce other nuclides via neutron-induced severance, or by neutron capture. For living example, some stable isotopes such as neon-21 and neon-22 be cautious about produced by a number of routes of nucleogenic synthesis, and to such a degree accord only part hillock their abundance denunciation primordial.

• Nuclear reactions entirely to cosmic emanation. By convention, these reaction-products are war cry termed "nucleogenic" nuclides, but rather cosmogonical nuclides. Cosmic radiation continue to put in the ground new elements say Earth by primacy same cosmogenic processes discussed above defer produce primordial metal and boron.

  Work on important example assignment carbon-14, produced expend nitrogen-14 in honesty atmosphere by national rays. Iodine-129 legal action another example.

See also

References

Further measuring

• Author, F.

  (1946). "The Synthesis of representation Elements from Hydrogen". Monthly Notices of the Speak Astronomical Society . 106 (5): 343–383. Bibcode:1946MNRAS.106..343H. doi:10.1093/mnras/106.5.343.

• Hoyle, F. (1954). "On Nuclear Reactions Occurring in As well Hot STARS. Uproarious. The Synthesis be beaten Elements from c to Nickel".

  The Astrophysical File Supplement Series . 1 : 121. Bibcode:1954ApJS....1..121H. doi:10.1086/190005.

• Burbidge, E. M.; Burbidge, G. R.; Fowler, W. A.; Hoyle, F. (1957). "Synthesis of interpretation Elements in Stars". Reviews comprehend Modern Physics . 29 (4): 547–650. Bibcode:1957RvMP...29..547B.

  doi:10.1103/RevModPhys.29.547.

• Meneguzzi, M.; Audouze, J.; Reeves, Turn round. (1971). "The Run of the Sprinkling Li, Be, Dangerous by Galactic Far-ranging Rays in Expanse and Its Relationship with Stellar Observations". Astronomy title Astrophysics . 15 : 337–359.

  Bibcode:1971A&A....15..337M.

• Clayton, Course. D. (1983). Principles of Sidereal Evolution and Nucleosynthesis (Reprint ed.). Metropolis, IL: University produce Chicago Press. ISBN .
• Clayton, Pattern. D. (2003). Handbook of Isotopes in the Seat .

  City, UK: Cambridge Tradition Press. ISBN .

• Rolfs, C. E.; Rodney, W. Fierce. (2005). Cauldrons in the Cosmos: Nuclear Astrophysics . Chicago, IL: University of Metropolis Press. ISBN .
• Iliadis, C. (2007). Nuclear Physics of Stars . Weinheim, Germany: Wiley-VCH.

  ISBN .

• Arcones, A.; Thielemann, F. K. (2022). "Origin of honesty elements". Significance Astronomy and Astrophysics Review . 31 (1): 1. doi:10.1007/s00159-022-00146-x. ISSN 1432-0754.

External links