Model atmospheres and specra of hydef giants and peculiar stars

Model atmospheres and specra of hydef giants

and peculiar stars

Yakiv V.PavlenkoYakiv V.Pavlenko

Main astronomical observatoryMain astronomical observatory

27 Sabolotnoho, Kyiv, Ukraine 27 Sabolotnoho, Kyiv, Ukraine

www.mao.kiev.ua/staff/ypwww.mao.kiev.ua/staff/yp

CollaboratorsCollaborators

J.Tennyson (UCL)J.Tennyson (UCL)

Greg Harries (UCL)Greg Harries (UCL)

Yakovina Yakovina Larisa(MAO)Larisa(MAO)

Kaminsky Bogdan Kaminsky Bogdan (MAO)(MAO)

Hugh Jones (UH)Hugh Jones (UH)

Bob Barver (UCL)Bob Barver (UCL)

Nye Evans(Keele)Nye Evans(Keele)

Hilmar Hilmar Duerbeck(OU)Duerbeck(OU)

Sveta Zhukovska Sveta Zhukovska (MAO)(MAO)

Thomas GeballeThomas Geballe

(Gemini)(Gemini)

Stars of interest:Stars of interest:Hydrogen-rich starsHydrogen-rich stars

--- --- M-giantsM-giants--- --- C-giantsC-giants--- --- V838 MonV838 Mon--- --- RS OphRS Oph

Hydrogen poor starsHydrogen poor stars------ R CrB et al.R CrB et al.------ Sakurai’s objectSakurai’s object

OutlineOutline

Model atmospheres and fits to Model atmospheres and fits to SEDsSEDs

Isotopic ratios (Isotopic ratios (1212C/C/1313C)C)

Abundances Abundances

PROCEDUREPROCEDURE

Model atmospheresModel atmospheres

SAM12 (ATLAS12)SAM12 (ATLAS12)

1D,1D,

Convection + radiation,Convection + radiation,

LTE,LTE,

No sinks and sources of No sinks and sources of energyenergy

Opacity sampling forOpacity sampling for

line opacityline opacity

Synthetic spectraSynthetic spectra WITAWITA1D,1D,LTE,LTE,Voigt function for linesVoigt function for linesVCS theory for H linesVCS theory for H linesSEDsSEDs

OPACITIES:OPACITIES:

C/O < 1,C/O < 1,Opacity sources:Opacity sources:

VO, TiO;VO, TiO;

HH22O, COO, CO

MethaneMethane

C/O > 1C/O > 1

CN, CO, CH, CN, CO, CH, CC22,HCN, C,HCN, C33,,

--- [H]?? --- [H]??

--- isotopes!--- isotopes!

Opacities (missed continuum Opacities (missed continuum absorption in the blue, line lists absorption in the blue, line lists (both atomic and molecular), (both atomic and molecular), isotops,isotops,

chemical abundances and chemical abundances and equilibrium,equilibrium,

3-D convection,3-D convection, sphericity effects,sphericity effects,the dust,the dust,stellar winds.stellar winds.

Problems:

“...Given the web of interconnected uncertainties and errors presented here, one is initially tempted to give up on stellar atmospheres completely and turn to something simple like cosmology.”

V.Trimble & R.A. Bell:

Astronomy often progresses amoeba-like: the advance in one pseudopod may not move the animal very far, but permits other parts to advance in their turn and can reveal portions of the organism that are in danger of being left behind. V.Trimble, R.A.Bell, Q.Jl.R.astr.Soc.(1981),22, 361-

379

M-giantsM-giantsvsvs

C-giantsC-giants

H-def stars

Asplund et al. (2000)

Family of R CrB stars

Opacities...

Pavlenko (2003)

Pavlenko (2003)

Topbase vs kurucz & Hofsaess (Pavlenko & Zhukovska 2003)

http://www.mao.kiev.ua/

staff/yp/Results/CNO_bf.tar.gz

Pavlenko (2003)

Model atmospheres & spectra vs

opacities & H/He

Sakurai's object (V4334 Sgr)Sakurai's object (V4334 Sgr)

CO in Arcturus

CO in Sakurai's object

to be continued...

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