@MastersThesis{Botelho:2017:CaNiAn,
author = "Botelho, Rafael Bueno",
title = "Carbono e nitrog{\^e}nio em an{\~a}s de tipo solar com e sem
planetas",
school = "Instituto Nacional de Pesquisas Espaciais (INPE)",
year = "2017",
address = "S{\~a}o Jos{\'e} dos Campos",
month = "2017-03-02",
keywords = "estrela do tipo solar, abund{\^a}ncia, espectroscopia
{\'o}ptica, s{\'{\i}}ntese espectral estelar, exoplanetas,
solar type star, abundance, optical spectroscopy, spectral stellar
synthesis, exoplanets.",
abstract = "Neste trabalho apresentamos os resultados da an{\'a}lise de
espectros estelares no intuito de derivarmos a abund{\^a}ncia
fotosf{\'e}rica do carbono (C) e nitrog{\^e}nio (N) para
estrelas an{\~a}s do tipo solar, com e sem planetas j{\'a}
detectados. Existem trabalhos que mostram que C e N (dois
elementos vol{\'a}teis) s{\~a}o mais abundantes em estrelas com
planetas, bem como h{\'a} trabalhos que afirmam que estrelas com
planetas s{\~a}o deficientes em elementos refrat{\'a}rios com
rela{\c{c}}{\~a}o aos vol{\'a}teis. C e N s{\~a}o elementos
vol{\'a}teis, cuja abund{\^a}ncias devem ser comparadas com as
abund{\^a}ncias de elementos refrat{\'a}rios a fim de verificar
a contribui{\c{c}}{\~a}o da forma{\c{c}}{\~a}o planet{\'a}ria
na composi{\c{c}}{\~a}o da estrela hospedeira. Analisando
transi{\c{c}}{\~o}es moleculares na faixa de 3300\$\AA\$ a
5300\$\AA\$ derivamos a abund{\^a}ncia do C e N para duas
amostras de estrelas distintas: (i) parte da amostra de Y. Takeda
(espectros coletados no Observat{\'o}rio Okayama, com
resolu{\c{c}}{\~a}o R=70.000 e raz{\~a}o sinal-ru{\'{\i}}do
S/N > 320) e (ii) 4 pares de estrelas similares de M. Carlos
(espectros coletados no telesc{\'o}pio Magellan, Las Campanas
Observatory, R=65.000 e S/N > 300). Os espectros da amostra de Y.
Takeda precisaram ter o fluxo normalizado, estando j{\'a}
reduzidos. Os espectros da amostra de M. Carlos j{\'a} se
encontravam com fluxo normalizado. Empregando o c{\'o}digo de
s{\'{\i}}ntese espectral MOOG, que resolve o transporte
radiativo numa fotosfera estelar sob a hip{\'o}tese de
equil{\'{\i}}brio termodin{\^a}mico local, definimos um
conjunto de linhas moleculares como bons indicadores das
abund{\^a}ncia do C e N, tendo medido tais abund{\^a}ncias
elementais com erros bastante aceit{\'a}veis para o
prop{\'o}sito deste estudo. As linhas espectrais s{\~a}o dos
sistemas eletr{\^o}nicos A-X do CH, D-A do C2, B-X do CN e A-X do
NH (este {\'u}ltimo apenas empregado para an{\'a}lise
espectrosc{\'o}pica da amostra de M. Carlos). Encontramos numa
das estrelas de um par de estrelas similares da amostra de M.
Carlos, a princ{\'{\i}}pio ambas sem planetas, que mostra
defici{\^e}ncia de elementos refrat{\'a}rios com
rela{\c{c}}{\~a}o aos vol{\'a}teis, sugerindo que ela deva
possuir planeta(s), terrestre ou gasoso e a outra n{\~a}o.
Notamos tamb{\'e}m que estrelas an{\'a}logas solares do disco
fino com planetas gasosos s{\~a}o ligeiramente mais abundantes em
C e N como ocorre para o Fe. ABSTRACT: In this work we present the
results of stellar spectral analysis in order to derive the
photospheric abundance of carbon (C) and nitrogen (N) for solar
type dwarf stars, with and without already detected planets. There
are works that show that C and N (two volatile elements) are more
abundant in stars with planets, as well as works which affirm that
stars with planets are deficient in refractory elements with
respect to volatiles. C and N are volatile elements whose
abundances must be compared with the abundances of refractory
elements in order to verify the contribution of the planetary
formation in the composition of the host star. Analyzing molecular
transitions in the range of 3300\$\AA\$ to 5300\$\AA\$ we
derive abundance of C and N for two distinct star samples: (i)
part of the Y. Takeda sample (Spectra collected at the Okayama
Observatory, with a resolution of R = 70,000 and signal-to-noise
ratio S/N>320) and (ii) 4 pairs of similar stars of M. Carlos
(spectra collected in the Magellan telescope, Las Campanas
Observatory, R = 65,000 and S/N>300). The spectra of the Y. Takeda
sample had to have the normalized flow already reduced. The
spectra of the sample of M. Carlos were already with normalized
flux. Using the MOOG spectral synthesis code, which solves the
radiative transport in a stellar photosphere under the hypothesis
of local thermodynamic equilibrium, we defined a set of molecular
lines as good indicators of the abundance of C and N, having
measured such elemental abundances with errors quite acceptable
for the purpose of this study. The spectral lines are from the
electron systems of CH A-X, C2 D-A, CN B-X and NH A-X (the latter
only used for spectroscopic analysis of the M. Carlos sample). We
found in one of the stars of a pair of similar stars of the sample
of M. Carlos, at first both without planets, that shows deficiency
of refractory elements with respect to the volatile ones,
suggesting that it must own planet(s), terrestrial or gaseous and
the other do not. We also note that thin disk solar-analog stras
with gaseous planets are slightly more abundant in C and N as is
the case for Fe.",
committee = "Jablonski, Francisco Jos{\'e} (presidente) and Milone, Andr{\'e}
de Castro (orientador) and Braga, Jo{\~a}o and Rossi, Silvia
Cristina Fernandes",
copyholder = "SID/SCD",
englishtitle = "Carbon and nitrogen in solar type dwarfs with and without
planets",
language = "pt",
pages = "122",
ibi = "8JMKD3MGP3W34P/3NCMP98",
url = "http://urlib.net/ibi/8JMKD3MGP3W34P/3NCMP98",
targetfile = "publicacao.pdf",
urlaccessdate = "01 maio 2024"
}