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The R.A.P. Project (Reviews of Astro-Ph) 2003

Ekzoplanety
(Arhiv Ekzoplanety:
v.2, 2004, v.1, 2002-2003)

Vypusk 63. 16-31 dekabrya 2003

astro-ph/0312382 "Oziris" (HD209458b), isparyayushayasya planeta ("Osiris" (HD209458b), an evaporating planet)
Authors: Alfred Vidal-Madjar & Alain Lecavelier des Etangs (IAP)
Comments: 8 pages, 7 figures

Nablyudeniya prohoda planety po disku zvezdy HD209458 solnechnogo tipa pokazali udivitel'nuyu kartinu. Razmer planety raven 4.3RJ, chto prevyshaet razmer radiusa Rosha dlya etoi planety, sostavlyayushii 3.6RJ. Eto oznachaet, chto planeta teryaet svoi vneshnie sloi. Etot fakt podtverzhdayut i izmereniya luchevyh skorostei, registriruyushie potok veshestva s otnositel'noi skorost'yu -130 km/s (znak minus oznachaet dvizhenie k nam), t.e. vyshe skorosti ubeganiya ot planety.

Etomu zhe ob'ektu posvyashena stat'ya astro-ph/0312384 togo zhe nauchnogo kollektiva "Temp ispareniya goryachih Yupiterov i obrazovanie Htonianskih planet".


Vypusk 61. 16-30 noyabrya 2003

astro-ph/0311541 Spektroskopiya [Fe/H] 98 zvezd s planetami: issledovanie veroyatnosti obrazovaniya planet (Spectroscopic [Fe/H] for 98 extra-solar planet-host stars: Exploring the probability of planet formation)
Authors: N. C. Santos et al.
Comments: 15 pages, 9 figures, Accepted for publication in A&A

Nekotoroe vremya nazad zapodozrili, chto veroyatnost' sushestvovaniya planetnoi sistemy sil'no zavisit ot metallichnosti zvezdy (t.e. ot soderzhaniya elementov tyazhelee geliya). V dannoi rabote avtory issleduyut etot vopros na ochen' bol'shoi vyborke zvezd.

Osnovnym vyvodom raboty yavlyaetsya podtverzhdenie sil'noi zavisimosti veroyatnosti obrazovaniya planetnoi sistemy ot metallichnosti.


Vypusk 59. 19-31 oktyabrya 2003

astro-ph/0310695 Metallichnost', obrazovanie planet i migraciya (Metallicity, planetary formation and migration)
Authors: M. Livio, J. E. Pringle
Comments: 4 pages

Imeyushiesya dannye po ekzoplanetam govoryat o nalichii chetkoi korrelyacii mezhdu veroyatnost'yu uvidet' planetu i metallichnost'yu zvezdy. Mozhno bylo by polagat', chto eto effekt selekcii, svyazannyi vot s chem. Sovremennye metodiki obnaruzhivayut massivnye planety na blizkih orbitah (goryachie yupitery). Polagayut, chto planety migrirovali na eti orbity s bolee dalekih. Znachit, mozhno spekulirovat' o korrelyacii metallichnost'-migraciya. Avtory dannoi raboty vnimatel'no issledovali takuyu vozmozhnost' i ne nashli nikakih osnovanii v pol'zu dannoi gipotezy. Stalo byt', zaklyuchayut oni, est' real'naya korrelyaciya mezhdu metallichnost'yu i planetami.


Vypusk 58. 01-17 oktyabrya 2003

astro-ph/0310084 Registraciya planet, "prohodyashih po diskam zvezd", s promezhutochnymi periodami s pomosh'yu seti malyh teleskopov - transitsearch.org (Detection of Intermediate-Period Transiting Planets with a Network of Small Telescopes: transitsearch.org)
Authors: S.Seagroves et al.
Comments: 11 pages, 3 figures, 1 table; accepted for the December PASP

Dlya obnaruzheniya planet-gigantov pri ih prohozhdenii po diskam zvezd trebuetsya fotometriya s otnositel'noi tochnost'yu ~1%. Na eto sposobny malye i dazhe lyubitel'skie teleskopy. Zato zhelatel'no vklyuchit' v etu programmu kak mozhno bol'shee chislo instrumentov, raspolozhennyh v razlichnyh tochkah Zemli. Takaya set' smozhet dostatochno effektivno obnaruzhivat' planety s orbital'nymi periodami ot 10 do 200 dnei u yarkih (V<11m) zvezd. Podrobnosti na saite transitsearch.org.


astro-ph/0310121 Apsidal'naya korotaciya pri rezonanse srednih dvizhenii: na primere planetnoi sistemy 55 Cancri (The apsidal corotation in mean motion resonance: 55 Cancri as an example)
Authors: Li-Yong Zhou et al.
Comments: 8 pages, 8 figures

Dve vnutrennie planety zvezdy 55 Cancri obrashayutsya v rezonanse 3:1 (po srednemu dvizheniyu). Poskol'ku orbity etih planet dostatochno ellipticheskie, to dinamiku takogo rezonansa prishlos' rassmatrivat' v obshem sluchae (a ne dlya krugovyh orbit, kak v Solnechnoi sisteme). V etoi situacii v podobnoi sisteme vozmozhno neskol'ko tipov ustoichivogo rezonansnogo dvizheniya.


obzor astro-ph/0310218 Prilivnaya dissipaciya vo vrashayushihsya planetah-gigantah (Tidal dissipation in rotating giant planets)
Authors: G.I.Ogilvie, D.N.C.Lin
Comments: 74 pages, 12 figures, subm. ApJ

Rech' idet o planetah-gigantah v Solnechnoi sisteme. Okazyvaetsya ochen' mnogo informacii o nih, v chastnosti o ih vnutrennem stroenii, mozhno poluchit' izuchaya prilivy, kotorye vyzyvayut na etih planetah ih naibolee massivnye sputniki.

V dannom obzore vy naidete vse: teoriyu staticheskih i dinamicheskih prilivov (prilivnyh oscillyacii), rezul'taty chislennogo modelirovaniya i, konechno, prilozhenie k ekzoplanetam.

Rezul'tat modelirovaniya prilivnogo otklika tverdotel'no vrashayusheisya planety.


Vypusk 56. 13-20 sentyabrya 2003

astro-ph/0309361 Obnaruzhenie blizkih vnesolnechnyh planet-gigantov s pomosh'yu zvezdnogo interferometra Fur'e-Kel'vina (Detection of Close-In Extrasolar Giant Planets Using the Fourier-Kelvin Stellar Interferometer)
Authors: W.C.Danchi et al.
Comments: 8 pages, 3 figures, accepted ApJ Letters.

Etot interferometr eshe ne zapushen i dazhe ne postroen, rech' idet o tom, smozhet li on obnaruzhivat' planety-giganty u blizhaishih zvezd v pryamyh nablyudeniyah. Modelirovaniem etogo processa i zanimalis' avtory dannoi raboty. No snachala o parametrah interferometra. Predpolagaetsya, chto on budet sostoyat' iz dvuh 0.5 metrovyh zerkal raznesennyh na rasstoyanie 12.5 metra (eto minimal'naya konfiguraciya). Rabotat' instrument budet v infrakrasnom diapazone na volnah ot 1 do 6 mikron s ispol'zovaniem "dvuhvolnovoi" tehniki.

Teoreticheskaya proverka rabotosposobnosti interferometra proizvodilas' po uzhe otkrytym ekzoplanetam. Modelirovanie pokazalo, chto po krainei mere sem' iz nih mogli by byt' im obnaruzheny v pryamyh nablyudeniyah.


Vypusk 51. 21-31 iyulya 2003

astro-ph/0307341 KH15D: zvezda, zatmevaemaya bol'shim pylevym vihrem? (KH15D: a star eclipsed by a large scale dusty vortex?)
Authors: P. Barge, M. Viton
Comments: Accepted in ApJ Letters - 4 pages - 2 figures

Avtory vyskazyvayut predpolozhenie, chto zatmeniya zvezdy KH15D svyazany s vihrem pylevyh chastic, kotoryi vrashaetsya na rasstoyanii poryadka 0.2 astronomicheskih edinicy ot zvezdy. Razumeetsya, eto vazhno, t.k. takie zavihreniya v okolozvezdnyh diskah mogut imet' samoe neposredstvennoe otnoshenie k processu obrazovaniya planet.


astro-ph/0307339 Molodoi belyi karlik kak kompan'on pul'sara 1620-26: ukazaniya na rannee obrazovanie planet (A Young White Dwarf Companion to Pulsar 1620-26: Evidence for Early Planet Formation)
Authors: Steinn Sigurdsson et al.
Comments: 4 pages, published in Science (301, 193-196, 11 July 2003)

U pul'sara 1620-26 est' dva sputnika: zvezdnyi i planetnyi. S pomosh'yu Kosmicheskogo teleskopa udalos' ustanovit', chto zvezdnyi sputnik - eto malomassivnyi (0.3-0.4 massy Solnca) molodoi (pol milliarda let) belyi karlik. Naibolee veroyatnyi scenarii obrazovaniya takoi sistemy - dinamicheskoe vzaimodeistvie v yadre skopleniya. No togda poluchaetsya, chto planety yavlyayutsya rasprostranennoi sostavlyayushei sharovyh skoplenii s maloi metallichnost'yu. Imenno eto i yavlyaetsya osnovnym vyvodom raboty i osnovaniem dlya vtoroi chasti zagolovka stat'i.


Vypusk 49. 01-07 iyulya 2003

astro-ph/0307066 Planeta na krugovoi orbite s periodom 6 let (A Planet in a Circular Orbit with a 6 Year Period)
Authors: Brad D. Carter et al.
Comments: 12 pages

Otkryta planeta s massoi bolee dvuh mass Yupitera na krugovoi orbite s periodom 6 let, chto sootvetstvuet rasstoyaniyu 3.3 a.e. T.e. eto ne "goryachii yupiter", a nechto, vpolne pohozhee na nash "nastoyashii" Yupiter. Otkryt' takuyu planetu trudno s nablyudatel'noi tochki zreniya, poetomu ih izvestno dovol'no malo. V skorom vremeni (neskol'ko let) avtory obeshayut sushestvennoe uluchshenie situacii: obzoram stanut dostupny yupitery i saturny (t.e. planety na krugovyh orbitah s periodami poryadka 100 let). Budem zhdat' ...


Vypusk 48. 23-30 iyunya 2003


astro-ph/0306524 Kakaya dolya solncepodobnyh zvezd imeet planety? (What Fraction of Sun-like Stars have Planets?)
Authors: Charles H. Lineweaver, Daniel Grether
Comments: 21 pages, 7 figures, 4 tables

Seichas izvestno uzhe bolee 100 planet. Bol'shinstvo iz nih otkryto metodom izmereniya variacii luchevyh skorostei zvezd, t.e. po Dopleru. Dannyi metod imeet svoi t.n. selekcionnye effekty.
1. Est' predel na izmerenie skorosti (seichas poryadka 40 m/s). Eto stavit predel na massu planety.
2. Esli orbita dostatochno shirokaya, to orbital'nyi period budet bol'shim, a v techenie goda, to obnaruzhit' planetu s periodom bolee etogo vremeni vy ne mozhete.

Eti ogranicheniya oznachayut sleduyushee. Esli vy zadaetes' voprosom "kakaya dolya zvezd imeet planety", to vy ne mozhete prosto vzyat' chislo izvestnyh zvezd s planetami i razdelit' na polnoe chislo zvezd, vklyuchennyh v programmy nablyudenii (na dannyi moment v vos'mi proektah provedeny izmereniya dlya 1743 zvezd). Nuzhno uchityvat' selekcionnye effekty, ili zhe vydelyat' oblasti v prostranstve parametrov, gde eti effekty nevazhny. Takie raboty uzhe provodilis', stat'ya predstavlyaet soboi novuyu popytku.

Rezul'taty proshe vsego predstavit' na risunke.

Po gorizontal'noi osi otlozhen orbital'nyi period v dnyah (na verhnei gorizontal'noi osi eto produblirovano pokazom bol'shoi poluosi v astronomicheskih edinicah s ukazaniem polozheniya planet Solnechnoi sistemy). Po vertikal'noi osi otlozheno proizvedenie massy planety v massah Yupitera na sinus ugla naklona orbity k luchu zreniya (ugol naklona yavlyaetsya vazhnym parametrov, t.k., naprimer, yasno, chto esli my smotrim na sistemu s rebra, to effekt "boltaniya zvezdy" budet sil'nee vsego, a esli my smotrim "sverhu" , t.e. vidim sistemu plashmya, to effekta prosto ne budet). Belaya oblast' na risunke sootvetstvuet oblasti parametrov, gde effekty selekcii maly. Sootvetstvenno, tam obnaruzheno pochti 100 procentov iz vozmozhnyh planet. V temnoi oblasti effekty selekcii ochen' sil'ny. Srednyaya seraya oblast' sootvetstvuet promezhutochnoi situacii. Pryamougol'nikami pokazany oblasti parametrov, dlya kotoryh v rabotah raznyh avtorov byli polucheny ogranicheniya na dolyu solncepodobnyh zvezd s planetami. Vnizu risunka dany ssylki na eti raboty i privedena dolya v procentah.

Rezul'taty dannoi raboty pokazany zhirnymi sploshnoi i punktirnoi liniyami. Eti dannye v srednem okazyvayutsya bolee optimistichnymi, chem rezul'taty drugih rabot. Po mneniyu avtorov eto svyazano s tem, chto oni bolee akkuratno uchityvayut effekty selekcii, chto uvelichivaet chislo zvezd, u kotoryh planety eshe ne zaregistrirovany. V chastnosti, rezul'tat ne protivorechit gipoteze o tom, chto 100 procentov zvezd imeyut planety!

Ob otkrytii novoi planety s pomosh'yu izmereniya radial'nyh skorostei sm. stat'yu The ELODIE survey for northern extra-solar planets II. A Jovian planet on a long-period orbit around GJ 777 A.

Vypusk 46. 1-15 iyunya 2003

astro-ph/0306049 Statisticheskie svoistva ekzoplanet. I. Raspredelenie po periodam: ogranicheniya na migracionnyi scenarii (Statistical properties of exoplanets. I. The period distribution: constraints for the migration scenario)
Authors: S. Udry et al.
Comments: 9 pages, Accepted in A&A

Seichas izvestno uzhe dostatochno mnogo ekzoplanet (okolo sotni), poetomu mozhno navodit' statistiku, chto i delaetsya v rabotah mnogih avtorov (my uzhe pisali o nekotoryh iz nih). V etoi stat'e avtory provodyat detal'noe issledovanie raspredeleniya planet razlichnoi massy (vydelyaya dve osnovnye gruppy: massivnye - s massoi bolee 2 mass Yupitera, i malomassivnye - s massoi menee 0.75 massy Yupitera) po orbital'nym periodam. Pokazana statisticheskaya znachimost' nekotoryh vazhnyh osobennostei raspredelenii. Takie dannye nakladyvayut ogranicheniya na scenarii migracii planet. Krome togo, imeyushiesya raspredeleniya pozvolyat bolee produktivno provodit' posleduyushie poiski.

Vypusk 45. 26-31 maya 2003

astro-ph/0305536 Massy i naklony orbit planet v sisteme pul'sara PSR B1257+12 (Masses and orbital inclinations of planets in the PSR B1257+12 system)
Authors: Maciej Konacki and Alex Wolszczan
Comments: 2 figures, to appear in ApJL

U millisekundnogo pul'sara PSR B1257+12 s periodom 6.2 ms dve planety. Esli prinyat', chto massa pul'sara ravna 1.4Mo (standartnaya massa neitronnoi zvezdy), to massy planet sostavlyayut 4.3+/-0.2M3 i 3.9+/-0.2M3, sootvetstvenno (M3 - massa Zemli). Naklony orbit k luchu zreniya 53.4o i 47.3o, t.e. ih orbity prakticheski komplanarny. Poskol'ku planety obrashayutsya vokrug pul'sara v rezonanse 3:2, to eto podtverzhdaet gipotezu ob ih vozniknovenii iz diska vokrug pul'sara.

astro-ph/0305522 Poisk ekzoplanet s pomosh'yu opticheskogo koronografa (Terrestrial Planet Finding with a Visible Light Coronagraph)
Authors: M. J. Kuchner and D. N. Spergel
Comments: 8 pages, 1 figure

Vnezatmennye koronografy - teleskopy prednaznachennye dlya nablyudeniya slaboi solnechnoi korony ryadom s gorazdo bolee yarkim Solncem. Vse v ih konstrukcii posvyasheno resheniyu dvuh zadach: umen'sheniyu parazitnogo rasseyaniya sveta i vozmozhnosti registracii izobrazhenii s ogromnymi perepadami yarkosti. Legko videt', chto eto te zhe samye trebovaniya, kotorye voznikayut pri popytke obnaruzhit' planetu u drugoi zvezdy po otrazhennomu eyu svetu. V dannoi stat'e v teoreticheskom klyuche rassmatrivaetsya vopros o primenimosti koronograficheskoi tehniki dlya obnaruzheniya ekzoplanet iz kosmosa i o neobhodimyh dlya etogo izmeneniyah v apparature.

astro-ph/0305500 Ustoichivost' orbit planet zemnogo tipa v blagopriyatnyh dlya zhizni zonah izvestnyh planetnyh sistem (The Stability of the Orbits of Earth-mass Planets in and near the Habitable Zones of Known Exoplanetary Systems)
Authors: Barrie W Jones, David R Underwood, P Nick Sleep
Comments: 6 pages, 2 Figures, Heidelberg Conference titled "The Search for Other Earths"

Seichas izvestno uzhe okolo 100 planetnyh sistem. No vse eto planety-giganty. Stoit li iskat' planety zemnogo tipa imenno v etih sistemah? Nahodyatsya li takie planety v usloviyah, kogda v principe vozmozhna zhizn' zemnogo tipa? Avtory stat'i rasschitali ustoichivost' orbit tipa Zemli dlya devyati izvestnyh sistem i pokazali, chto v bol'shinstve sluchaev oni yavlyayutsya ustoichivymi dlya rasstoyanii, sootvetstvuyushih blagopriyatnym dlya zhizni usloviyam. Ekstrapolyaciya na vse 93 sistemy vokrug zvezd glavnoi posledovatel'nosti, izvestnye na dannyi moment, daet takoi rezul'tat: primerno v treti sluchaev mozhno ozhidat' nalichie ustoichivyh orbit v "obitabel'nyh" zonah.

O budushih poiskah planet zemnogo tipa s pomosh'yu koronografov sm. nebol'shoi (8 stranic) obzor "Terrestrial Planet Finding with a Visible Light Coronagraph".


Vypusk 44. 17-23 maya 2003

miniobzor astro-ph/0305337 Poisk ekzoplanet zemnogo tipa (The Search for Extrasolar Earth-like planets)
Authors: S. Seager
Comments: 10 pages, invited review paper, Earth and Planetary Science Letters Frontiers, preprint version--see Journal ref for final version
Journal-ref: Earth and Planetary Science Letters (2003) 208, 113-124

Otkrytie "drugih Yupiterov" - eto konechno ochen' interesno. No hochetsya, ochen' hochetsya!, "drugie Zemli". Poka eto tehnicheski ochen' neprosto: massa u Zemli malen'kaya, razmer nebol'shoi. Poetomu ni po variaciyam skorosti zvezdy, ni po prohozhdeniyam planety po disku zvezdy, takuyu "kroshku" ne otkroesh'". Nado razvivat' tehnologii, i etim aktivno zanimayutsya. Budut special'nye nazemnye i kosmicheskie nablyudatel'nye proekty, celikom posvyashennye poisku planet zemnogo tipa. V obzore kratko opisyvayutsya vse problemy, svyazannye s poiskami planet tipa Zemli, a takzhe rasskazyvaetsya o gotovyashihsya nablyudeniyah. Krome togo, avtor upominaet novye teoreticheskie razrabotki v etoi oblasti.


Vypusk 42. 1-9 maya 2003


proekt astro-ph/0305030 Perspektivy otkrytiya planet s pomosh'yu kosmicheskogo interferometra (Planet finding prospects for the Space Interferometry Mission)
Authors: Eric B. Ford, Scott Tremaine
Comments: 30 pages, 12 figures

Seichas planety v osnovnom otkryvayut po nablyudeniyam radial'nyh skorostei zvezd. Takoi metod naibolee chuvstvitelen k massivnym planetam na dostatochno blizkoi orbite. Hotya otkryto uzhe okolo 100 planet vse oni bolee-menee odnotipny. Bylo by interesno naiti planety tipa Zemli: kak v smysle massy, tak i v smysle rasstoyaniya ot central'noi zvezdy. Dlya etogo podhodyat vysokotochnye astrometricheskie metody.

SIM - Space Interferometry Mission. Eto kosmicheskii interferometr s bazoi 10 metrov. Zapusk planiruetsya na 2009 g. Za 5 let raboty dlya izbrannyh zvezd do 20 velichiny (!) sputnik poluchit astrometricheskie dannye s tochnost'yu v neskol'ko tysyachnyh dolei uglovoi sekundy.

V stat'e avtory rassmatrivayut skol'ko (i kakih) planet smozhet otryt' SIM. Ocenki pokazyvayut, chto mozhno ozhidat' otkrytiya vsego 1-2 planet zemnoi massy, okolo 5-25 planet s massoi menee 20 zemnyh. Vsego zhe ozhidaetsya otkrytie primerno 100 planet. Ocenki ne ochen' vpechatlyayushie, tem bolee, chto oni osnovany na dovol'no optimisticheskih predpolozheniyah.


Vypusk 39. 12-18 aprelya 2003

astro-ph/0304284 Predely na kolichestvo i orbity vnesolnechnyh planet po sobytiyam eksperimenta OGLE za 1998-2000 gg. (Microlensing limits on numbers and orbits of extra-solar planets from the 1998-2000 OGLE events)
Authors: Yiannis Tsapras et al.

Standartnaya simmetrichnaya krivaya bleska sil'no iskazhaetsya, esli linza yavlyaetsya dvoinoi. Iskazhenie zametno dazhe pri ochen' bol'shom otnoshenii mass ob'ektov, t.e. kogda vtoroi komponent yavlyaetsya planetoi. Dlya obnaruzheniya takih iskazhenii byli izucheny 145 sobytii mikrolinzirovaniya, zafiksirovannyh v eksperimente OGLE za 1998-2000 gg. Vyvod - planetami s massoi Yupitera ili vyshe na rasstoyanii ot 1 do 4 astronomicheskih edinic obladayut ne bolee 21% zvezd-linz.


(Arhiv Ekzoplanety:
v.2, 2004, v.1, 2002-2003)

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