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Horké Hvězdy-Mik Přírodov ědecká fakulta Masarykovy univerzity Ústav teoretické fyziky a astrofyziky Zden ěk Mikulášek, Ji ří Krti čka Fyzika horkých hv ězd Skripta Brno 2007 2 Skripta nov ě zavedeného specializovaného p ředm ětu ur čeného všem zájemc ům o problemati- ku výzkumu horkých hv ězd. Revize textu 18.2.2007 1 Úvod............................................................................................................4 1.1 Pro č zrovna fyzika horkých hv ězd? ........................................................................ 4 1.2 Definice horkých hv ězd............................................................................................ 4 1.3 Charakteristiky r ůzných typ ů horkých hv ězd a jejich vývojový status.............. 5 1.3.1 (Herbigovy) Ae/Be hv ězdy .................................................................................... 7 1.3.2 Horké hv ězdy hlavní posloupnosti......................................................................... 7 1.3.3 Prom ěnné typu δ Scuti ........................................................................................... 9 1.3.4 Prom ěnné typu β Cephei...................................................................................... 11 1.3.5 B[e] hv ězdy .......................................................................................................... 11 1.3.6 Ob ři a veleob ři populace I.................................................................................... 12 1.3.7 Za řivé modré prom ěnné hv ězdy........................................................................... 13 1.3.8 Wolfovy-Rayetovy hv ězdy .................................................................................. 13 1.3.9 Horcí podtrpaslíci................................................................................................. 14 1.3.10 Jádra planetárních mlhovin .................................................................................. 14 1.3.11 Bílí trpaslíci.......................................................................................................... 14 1.3.12 Prom ěnné typu ZZ Ceti........................................................................................ 15 1.3.13 Horizontální v ětev obr ů populace II..................................................................... 15 1.3.14 Prom ěnné typu RR Lyrae..................................................................................... 16 1.3.15 Mod ří opozdilci (blue stragglers)......................................................................... 17 1.3.16 První hv ězdy ve vesmíru ...................................................................................... 17 2 Stavba a vývoj hv ězd a dvojhv ězd.........................................................18 2.1 Obecné vlastnosti hv ězdného vývoje .................................................................... 18 2.2 Před vstupem na hlavní posloupnost.................................................................... 19 2.3 Hv ězdy hlavní posloupnosti................................................................................... 19 2.3.1 Délka fáze hv ězdy hlavní posloupnosti................................................................ 20 2.3.2 Protonov ě-protonový řetězec a CNO cyklus........................................................ 21 2.3.3 Vývoj hv ězd na hlavní posloupnosti .................................................................... 22 2.4 Ob ři a veleob ři........................................................................................................ 24 2.4.1 Slupkové ho ření vodíku ....................................................................................... 24 2.4.2 Ho ření hélia a dalších prvk ů, vznik jader planetárních mlhovin.......................... 24 2.5 Vznik a vývoj bílých trpaslík ů ............................................................................... 25 2.6 Vývoj dvojhv ězd ..................................................................................................... 26 2.6.1 Klasifikace dvojhv ězd.......................................................................................... 26 2.6.2 Vývoj t ěsných dvojhv ězd..................................................................................... 26 3 Horké hv ězdy v galaxiích .......................................................................29 3.1 Zastoupení horkých hv ězd ve hv ězdné populaci ................................................. 29 3.2 Výskyt horkých hv ězd v Galaxii ........................................................................... 29 3.2.1 Asociace OB......................................................................................................... 30 3.2.2 Otev řené hv ězdokupy........................................................................................... 30 3.2.3 Horké hv ězdy populace II .................................................................................... 31 3.3 Horké hv ězdy v jiných galaxiích........................................................................... 31 3 3.4 Horké hv ězdy a mezihv ězdná látka ..................................................................... 32 3.4.1 Oblasti ionizovaného vodíku a jejich zá ření ....................................................... 32 3.4.2 Planetární mlhoviny ............................................................................................ 33 9 Chemicky pekuliární hv ězdy .................................................................70 9.1 Úvod......................................................................................................................... 70 9.2 Stru čná historie výzkumu CP hv ězd .................................................................... 70 9.2.1 α2 CVn – prototyp pekuliárních hv ězd ................................................................ 70 9.2.2 Cesta k modelu sklon ěného rotátoru .................................................................... 71 9.2.3 Spektrální klasifikace ........................................................................................... 71 9.3 Příčiny spektrální anomálie................................................................................... 72 9.3.1 Sou časná klasifikace CP hv ězd............................................................................ 73 9.3.2 Prom ěnnost CP hv ězd .......................................................................................... 74 9.3.3 Původ chemické anomálie.................................................................................... 75 9.3.4 Původ magnetického pole .................................................................................... 75 Charakteristiky CP hv ězd a metody jejich ur čování ..................................................... 75 9.4 Spektrální charakteristiky, abundance................................................................ 76 9.4.1 Po řizování a zpracování spekter........................................................................... 76 9.4.2 Identifikace spektrálních čar ................................................................................ 76 9.4.3 Abundance, modely atmosfér............................................................................... 77 9.5 Fotometrie CP hv ězd.............................................................................................. 77 9.5.1 Fotometrie CP hv ězd ve standardních systémech ................................................ 78 9.5.2 Absolutní spektrofotometrie (monochromatická fotometrie) .............................. 78 9.5.3 Maitzen ův index ∆a ............................................................................................. 79 9.6 Rotace ...................................................................................................................... 79 9.6.1 Periody rotace....................................................................................................... 79 9.6.2 Projekce rota ční rychlosti..................................................................................... 80 9.6.3 Aplikace a testování modelu šikmého rotátoru .................................................... 80 9.6.4 Polom ěry CP hv ězd.............................................................................................. 81 9.7 Magnetické pole a jeho zm ěny .............................................................................. 81 9.7.1 Zeeman ův jev ....................................................................................................... 81 9.7.2 Efektivní magnetické pole.................................................................................... 82 9.7.3 Zeeman ův analyzátor ........................................................................................... 82 9.7.4 Vodíkový magnetometr........................................................................................ 83 9.7.5 Povrchové magnetické pole ................................................................................. 83 9.7.6 Povaha magnetického pole................................................................................... 83 9.8 Spektroskopická prom ěnnost, rozložení prvk ů po povrchu .............................. 84 9.8.1 Mapování rozložení prvk ů (dopplerovské zobrazování, tomografie) .................. 84 9.9 Fotometrická prom ěnnost, .................................................................................... 84 9.9.1 Rychlá prom ěnnost CP2 hv ězd ...........................................................................
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