PAYDOISHI SISTEMAI SAYYORAHO

Olimon takhmin mekunand, ki abrnoki marhilai tashakkuli galaktika yo sistemai sitorahoi azim ast. Az rui in nazariyaho, sayyoraho mahsuli ilovagii paydo shudani sitoraho meboshand. CHunin nuqtai nazarro bori avval I.Kant dar asri HVIII peshnihod karda, minbad onro D.Koyper, D.Alven va R.Kameron bo dalelho tasdiq namudaand.

Sitorahoi nav dar dokhili gubornoki dida meshavand. Andozai marzhoe, ki az gazu changi bayni sitoraho jam shudaand, chand soli rushnoiro tashkil medihand. Abrnokiro dar hama joi galaktika didan mumkin ast. Takhmin meravad, ki sitoraho va sistemahoi digari sayyorahoi ba onho aloqamand dar dokhili hamin materiyai abrhoi azim hosil shudaand.

Bo yorii spektroskopiya oshkor gashtaast, ki moddahoi baynisitoragi az gazhoi gidrogen, geliy, neon va zarrachahoi gardu change, ki andozaashon yakchand mikron ast, iborat meboshad. Tarkibi onhoro metallho va elementhoi digar tashkil medihand. Az sababi nihoyat past budani harorat (10- 20 K), hamai moddaho, ba gayr az gazhoi nombar shuda, dar holati yakhbasta dar zarrachahoi gardu chang qaror dorand.

Elementhoi vaznintar va yak miqdori gidrogen az sitorahoi peshtar paydoshuda ba vujud meoyand. Baze az in sitoraho chun sitorai nav tarkish meyobad va ba muhiti bayni sitoraho gidrogeni boqimondaro bargardonida, qari onro bo elementhoi vaznintar gani megardonand.

Miqdori gaz dar fazoi bayni sitoraho hamagi 0,1 atomi N/sm 3 meboshad. Dar abrnoki miqdori on taqriban ba 1000 atomi N/sm 3 barobar ast, yane 10000 marotiba ziyod mebo shad. Dar 1 sm 3 havo takhminan 2,7kh1019 molekula mavjud ast.

Hangome, ki zeri tasiri joziba (gravitatsiya) dar natijai tadrijan takshin shudan va chaspidani gazu changhoi bayni sitoraho abri gazu changi azim ba vujud meoyad, vay noustuvor megardad. Dar on muvozinati bayni fishor va quvvai joziba khalal meyobad. Quvvai joziba bartari dorad, az hamin sabab abrho fishurda meshavand. Dar fazahoi avvali fishurdashavi garmie, ki hini tabdilyobii energiyai joziba ba energiyai nurposhi khorij meshavad, abrro tark mekunad, zero

zichii nisbii modda kam ast. Barobari afzudani zichii modda tagyirothoi nav ba vujud meoyand. Bo sababi joziba va havodisi digar (fluktuatsiya) abri azim ba abrhoi khurdtar judo meshavad, onho dar navbati khud porchahoero hosil mekunand, ki az jihati massa va andoza az sistemai oftobi chand marotiba buzurgtar meboshand.

CHunin abrhoi judoshudaro protoakhtaron menomand. Albatta, baze protoakhtaron (sitorahoi purra tashkil nayofta) az sistemai oftobi kalontar buda, sitorahoi kalon va garmtar hosil mekunand. Protoakhtaroni khurdtar boshad, sitorahoi khurdtar va sardtar hosil karda, nisbat ba sitorahoi kalon va garmtar sust inkishof meyoband. Buzurgii protoakhtaron mahdud ast, dar surati az on ziyod shudan, onho boz taqsim megardand; haddi poyoni onhoro hamon massai haddi aqale muayyan mesozad, ki baroi nigoh doshtani reaksiyai hastai lozim ast.

Saravval iqtidor (potensial)-i energiyai joziba, ki ba garmi tabdil meyobad (energiyai nurafshoni), dar rafti fishurdashavii joziba khorij meshavad. Ammo barobari afzudani zichii modda vay energiyai nurafshoniro beshtar furu mebarad va dar natija harorat baland meshavad. Nakhustpayvastagihoi sabuke, ki dar zarrachahoi chang yakhbastaand, bukhor meshavand. Ba N2, Ne va Ne chunin gazho, masalan NH3,

SN4 bugi ob va NCN omekhta meshavand. Gazho energiyai nurafshonii boqimondaro furu burda, dissotsiatsiya va duchori judoshavii ionho (ionizatsiya) megardand. Hangomi purra ionizatsiya shudani molekulaho harorat zud baland meshavad, (to vaqti nazdiki ba itmom rasidani fishurdashavi), zero fishori gaz quvvai kashishkhuriro barobar mekunad. Hamin tavr, fazoi tezi fishurdashavii joziba  (kollaps) ba itmom merasad. Dar hamin davrai tashakkul protoakhtaron javobgui sistemai sayyorahoi mo buda, laliero memonand, ki bo gafsii markaz va harorati takhminan 1000K barobari madori Mushtari (YUpiter) meboshand.

Tahavvuli chunin lalii protoakhtari davom karda, dar on digarguni ba amal meoyad va tadrijan fishurda meshavad. Hudi protoakhtar beshtar fishor yofta, buzurgtar va garmtar meshavad, zero garmi aknun faqat az boloi on ikhroj shuda metavonad. Az dokhili protoakhtaron ba ru baromadani harorat tavassuti jarayoni konveksioni ba amal meoyad.

Fazo az sathi boloi protoakhtaron to masofae, ki barobari madori Pluton ast, pur az abri gazu chang meboshad. Dar rafti chandin marotiba fishurdashavii murakkab, ki takhminan 10 mln. solro talab mekunad, zamoni harakati sistema boyad mahfuz monad. Tamomi galaktika charkh zada, dar 100 mln. sol yak gardish mekunad. Barobari fishurdashavii abrhoi gardu chang vaqti harakati onho tagyir nameyobad; chi qadar onho ziyodtar fishurda shavand, hamon qadar zudtar charkh mezanand. Binobar nigoh doshtani vaqti harakat abri changmonandi fishorkhurdai kurashakl to ba

Evolyutsiyai gazu changi abrnoki va hosil shudani lalii protoakhtari  abri lalishakl tagyir meyobad. Barobari fishurda shudani moddahoi boqimondai protoakhtaron harorati on baroi ogozi reaksiyai yakshavii atomhoi gidrogen kofist. Dar natijai reaksiya energiyai ziyod judo shuda, harorat baland megardad, to in ki quvvai oyandai fishurdai joziba barobar shavad.

Sayyoraho dar atrofi lalichai protoakhtari az boqimondai gaz va chang tashkil yoftaand. YAkjoyashavii changi bayni sitoraho zeri tasiri kashish khurii jozibagi ba hosil shudani sitoraho va sayyoraho ovarda merasonad va ravand takhminan 10 mln. solro dar bar megirad (1-4). Sitoraho dar sistemai asosi (4) hamroh shuda, dar tuli takhminan 800 mln. sol dar holati ustuvor memonand va tadrijan gidrogenro hosil mekunand. Sipas, sitoraho sistemai asosiro tark karda, to ba darajai surkhi (5 va 6) vase meshavand va sitorahoi khurdro dar badali 100 mln. soli oyanda “furu” mebarand. Badi chand hazor sol ba sifati sitorahoi tagyiryobanda nabz zadan (7), chun sitorai navtarin tarkish yofta (8) bilokhira to darajai rezai (pakanai) safedrang fishurda meshavad (9).

Garchand sayyoraho obekthoi azim ba hisob meravand, vale massai umumii onho hamagi 0,135% massai sistemai oftobiro tashkil medihand.

Sayyorai mo, hamchunin sayyorahoi digar, ki dar kadom mavzei lalichai protoakhtaron hosil nashavand, dar du mintaqai asosi joy megirand. Mintaqai dokhili dar sistemai oftobi az Merkuriy to kamari asteroidho pahn buda, min-

taqai khurdi sayyorahoi ba Zamin monand meboshand. Dar in jo, dar davrai sust fishurda shudani protoakhtaron harorat ba darajae baland ast, ki metallho bukhor meshavand.

Mintaqai sardi beruna doroi bugi N2O, gazhoi Ne, Ne va zarrachahoi pushidai N2O, NN3 va SN4 ast. Mintaqai beruna nisbat ba mintaqai dokhila moddahoi ziyodtar dorad.

Zero andozai on kalon ast va bisyor moddahoi sabuke, ki avval dar mintaqai darun budand, dar natijai faoliyati protoakhtaron berun tela doda meshavand.

YAke az rohhoi tartib dodani aksi tahavvuloti sitoraho va muayyan kardani sinnu soli onho tahlili judogonai sitoraho meboshad. Bo in usul masofai to sitoraro chen karda, tavassuti shuoi ba chashm ayoni on rangi har yak sitoraro muayyan kardan mumkin ast.

Agar shuoi didashavanda va masofa to sitora malum boshad, pas andozai mutlaqi sitoraro hisob kardan dushvori nadorad, chunki shuo nisbat ba masofai on mutanosibi chap meboshad. Buzurgii mutlaqi sitora surati khorij shudai energiya az mavqei sitora to shakhsi mushohidakunanda meboshad.

Rangi sitora harorati onro muayyan mekunad: rangi kabud ba sitorahoi nihoyat tafson, rangi safed ba sitorahoi garm, rangi surkh ba sitorahoi nisbatan sard taalluq dorad.

Dar rasmi 2.4 diagrammai Gertsshprung-Rassel, ki az fanni astronomiya ba shumo shinos ast, nishon doda shudaast. Dar rasm vobastagi bayni buzurgii mutlaqi sitoraho va rangi onho baroi bisyor sitoraho nishon doda shudaast.

Azbaski in diagramma sitorahoi andoza va sinnu solashon gunogunro darbar megirad, ba sitorahoe, ki tahavvulotashon dar davrahoi gunogun qaror dorad, muvofiq meboshad.

Bisyor sitoraho dar qismi mustaqimi diagrama joy giriftaand: sitoraho dar natijai tadrijan sukhtani gidrogeni dar onho buda, faqat tagyiryobii muvozinatro az sar meguzaronand. Dar in qismi diagramma, ki nizomi asosi

Hosilshavii sistemai sayyoraho nom dorad, sitorahoi massaashon kalon harorati baland tarro sohiband. Dar onho reaksiyai yakjoyashavii atomhoi gidrogen tez meguzarad va umrashon kutoh ast.

Sitorahoi massaashon nisbat ba oftob khurd harorati pasttar dorand. Dar onho yakjoyashavii atomhoi gidrogen sust guzashta, davomoti umrashon ziyod ast. Dar surati taqriban 10%-i zakhirai avvalai gidrogeni khudro sarf kardani yagon sitorai sistemai asosi, harrorati on past faromada vaseshavi ba amal meoyad. Takhmin meravad, ki sitorahoi azim «solkhurdaand» va qablan ba sitorahoi sistemai asosi taalluq doshtand. Dar vaqti daqiq muayn kardani sinnu soli sitoraho chunin dalelhoro ba inobat giriftan lozim ast. Tadqiqotho nishon medihand, ki sinnu soli yagon sitorai galaktikai mo az 1 mlrdu 100 mln. sol ziyod nest. Baze sitorahoi khurd niz hamin sinnu solro dorand.

Umri bisyor sitorahoi buzurg az in ham kamtar ast. Sitorai az hama azim dar sistemai asosi az 1 mln. sol ziyod istoda nametavonad. Oftob va digar sitorahoi andozaashon ba on barobar, qabl az on, ki ba darajai sitorahoi azimi surkh rasand, dar sistemai asosi 10 mln. sol meistand.

Savolho baroi sanjish:

1. Reaksiyai sintezi yadroi chist? Misol ored.
2. Muvofiqi farziyai Kant va Laplas sistemai sitoraho az materiyai gazu chang chi guna tashkil meyoband?
3. Oyo dar tarkibi khimiyavii sistemai sitoraho yagon farqiyat hast?