Abundances in the atmosphere of the metal-rich planet-host star HD 77338
Abundances of Fe, Si, Ni, Ti, Na, Mg, Cu, Zn, Mn, Cr and Ca in the atmosphere of the K-dwarf HD 77338 are determined and discussed. HD 77338 hosts a hot Uranus-like planet and is currently the most metal-rich single star to host any planet. Determination of abundances was carried out in the framewor...
Збережено в:
| Дата: | 2014 |
|---|---|
| Автори: | , , , |
| Формат: | Стаття |
| Мова: | English |
| Опубліковано: |
Головна астрономічна обсерваторія НАН України
2014
|
| Назва видання: | Advances in Astronomy and Space Physics |
| Онлайн доступ: | http://dspace.nbuv.gov.ua/handle/123456789/119803 |
| Теги: |
Додати тег
Немає тегів, Будьте першим, хто поставить тег для цього запису!
|
| Назва журналу: | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| Цитувати: | Abundances in the atmosphere of the metal-rich planet-host star HD 77338 / I.O. Kushniruk, Ya.V. Pavlenko, J.S. Jenkins, H.R.A. Jones // Advances in Astronomy and Space Physics. — 2014. — Т. 4., вип. 1-2. — С. 20-24. — Бібліогр.: 20 назв. — англ. |
Репозитарії
Digital Library of Periodicals of National Academy of Sciences of Ukraine| id |
irk-123456789-119803 |
|---|---|
| record_format |
dspace |
| spelling |
irk-123456789-1198032017-06-10T03:03:09Z Abundances in the atmosphere of the metal-rich planet-host star HD 77338 Kushniruk, I.O. Pavlenko, Ya.V. Jenkins, J.S. Jones, H.R.A. Abundances of Fe, Si, Ni, Ti, Na, Mg, Cu, Zn, Mn, Cr and Ca in the atmosphere of the K-dwarf HD 77338 are determined and discussed. HD 77338 hosts a hot Uranus-like planet and is currently the most metal-rich single star to host any planet. Determination of abundances was carried out in the framework of a self-consistent approach developed by Pavlenko et al. (2012). Abundances were computed iteratively by the ABEL8 code, and the process converged after 4 iterations. We find that most elements follow the iron abundance, however some of the iron peak elements are found to be over-abundant in this star. 2014 Article Abundances in the atmosphere of the metal-rich planet-host star HD 77338 / I.O. Kushniruk, Ya.V. Pavlenko, J.S. Jenkins, H.R.A. Jones // Advances in Astronomy and Space Physics. — 2014. — Т. 4., вип. 1-2. — С. 20-24. — Бібліогр.: 20 назв. — англ. 2227-1481 DOI: 10.17721/2227-1481.4.20-24 http://dspace.nbuv.gov.ua/handle/123456789/119803 en Advances in Astronomy and Space Physics Головна астрономічна обсерваторія НАН України |
| institution |
Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| collection |
DSpace DC |
| language |
English |
| description |
Abundances of Fe, Si, Ni, Ti, Na, Mg, Cu, Zn, Mn, Cr and Ca in the atmosphere of the K-dwarf HD 77338 are determined and discussed. HD 77338 hosts a hot Uranus-like planet and is currently the most metal-rich single star to host any planet. Determination of abundances was carried out in the framework of a self-consistent approach developed by Pavlenko et al. (2012). Abundances were computed iteratively by the ABEL8 code, and the process converged after 4 iterations. We find that most elements follow the iron abundance, however some of the iron peak elements are found to be over-abundant in this star. |
| format |
Article |
| author |
Kushniruk, I.O. Pavlenko, Ya.V. Jenkins, J.S. Jones, H.R.A. |
| spellingShingle |
Kushniruk, I.O. Pavlenko, Ya.V. Jenkins, J.S. Jones, H.R.A. Abundances in the atmosphere of the metal-rich planet-host star HD 77338 Advances in Astronomy and Space Physics |
| author_facet |
Kushniruk, I.O. Pavlenko, Ya.V. Jenkins, J.S. Jones, H.R.A. |
| author_sort |
Kushniruk, I.O. |
| title |
Abundances in the atmosphere of the metal-rich planet-host star HD 77338 |
| title_short |
Abundances in the atmosphere of the metal-rich planet-host star HD 77338 |
| title_full |
Abundances in the atmosphere of the metal-rich planet-host star HD 77338 |
| title_fullStr |
Abundances in the atmosphere of the metal-rich planet-host star HD 77338 |
| title_full_unstemmed |
Abundances in the atmosphere of the metal-rich planet-host star HD 77338 |
| title_sort |
abundances in the atmosphere of the metal-rich planet-host star hd 77338 |
| publisher |
Головна астрономічна обсерваторія НАН України |
| publishDate |
2014 |
| url |
http://dspace.nbuv.gov.ua/handle/123456789/119803 |
| citation_txt |
Abundances in the atmosphere of the metal-rich planet-host star HD 77338 / I.O. Kushniruk, Ya.V. Pavlenko, J.S. Jenkins, H.R.A. Jones // Advances in Astronomy and Space Physics. — 2014. — Т. 4., вип. 1-2. — С. 20-24. — Бібліогр.: 20 назв. — англ. |
| series |
Advances in Astronomy and Space Physics |
| work_keys_str_mv |
AT kushnirukio abundancesintheatmosphereofthemetalrichplanethoststarhd77338 AT pavlenkoyav abundancesintheatmosphereofthemetalrichplanethoststarhd77338 AT jenkinsjs abundancesintheatmosphereofthemetalrichplanethoststarhd77338 AT joneshra abundancesintheatmosphereofthemetalrichplanethoststarhd77338 |
| first_indexed |
2025-07-08T16:38:11Z |
| last_indexed |
2025-07-08T16:38:11Z |
| _version_ |
1837097489264541696 |
| fulltext |
Abundances in the atmosphere of the metal-rich
planet-host star HD 77338
I. O.Kushniruk1∗, Ya.V. Pavlenko2,3, J. S. Jenkins4, H.R.A. Jones3
Advances in Astronomy and Space Physics, 4, 20-24 (2014)
© I. O.Kushniruk, Ya.V. Pavlenko, J. S. Jenkins, H.R.A. Jones, 2014
1Taras Shevchenko National University of Kyiv, Glushkova ave., 2, 03127 Kyiv, Ukraine
2Main Astronomical Observatory of the NAS of Ukraine, Akademika Zabolotnoho str., 27, 03680 Kyiv, Ukraine
3Centre for Astrophysics Research, University of Hertfordshire, College Lane, Hat�eld, Hertfordshire AL10 9AB, UK
4Departamento de Astronomía, Universidad de Chile, Camino el Observatorio 1515, Las Condes, Santiago, Chile
Abundances of Fe, Si, Ni, Ti, Na, Mg, Cu, Zn, Mn, Cr and Ca in the atmosphere of the K-dwarf HD77338 are
determined and discussed. HD77338 hosts a hot Uranus-like planet and is currently the most metal-rich single star
to host any planet. Determination of abundances was carried out in the framework of a self-consistent approach
developed by Pavlenko et al. (2012). Abundances were computed iteratively by the ABEL8 code, and the process
converged after 4 iterations. We �nd that most elements follow the iron abundance, however some of the iron peak
elements are found to be over-abundant in this star.
Key words: stars: abundances, stars: atmospheres, stars: individual (HD 77338), line: pro�les
introduction
Determining the chemical composition of stars is
one of the primary goals of astrophysics. Such in-
vestigations help us to better understand the chem-
ical enrichment of the Galaxy and to make some
assumptions about the mechanisms involved in el-
ement evolution in the interstellar medium, and in
stellar atmospheres in particular [12]. While study-
ing the Sun, the problem of the abundances of cer-
tain atoms necessitated a model to explain this. It
was �nally explained with the introduction of the pp-
and CNO- cycles in the interior of the Sun. However,
this was not su�cient to explain the presence of large
amounts of Helium. The next step in studying the
evolution of elements was the introduction of nucle-
osynthesis theory. Modern scienti�c understanding
is that chemical elements were formed as a result of
the processes occurring in stars, leading to evolution-
ary changes of their physical conditions. Therefore,
the problem of nuclide formation is also closely re-
lated to the issue of the evolution of stars and plane-
tary systems. Recently Jenkins et al. [5] announced
the discovery of a low-mass planet orbiting the super
HD77338 as part of our ongoing Calan-Hertfordshire
Extrasolar Planet Search [6]. The best-�t planet
solution has an orbital period of 5.7361 ± 0.0015
days and with a radial velocity semi-amplitude of
only 5.96 ± 1.74ms−1, giving a minimum mass of
+4.7
−5.3M⊕. The best-�t eccentricity from this solution
is 0.09+0.25
−0.09, and is in the agreement with results of
a Bayesian analysis and a periodogram analysis.
According to modern theory, the formation of the
nucleus of chemical elements from carbon to iron is
the result of thermonuclear reactions involving He,
C, O, Ne and Si in stars. After the depletion of
hydrogen reserves, a star's core starts running a 3α
reaction, where it produces a number of elements as
a result of the following transformations:
3 4He −→ 12C, 12C + 4He −→ 16O + γ,
16O + 4He −→ 20Ne + γ.
After reaching a speci�c threshold temperature, car-
bon begins fusing with the formation of Ne, Na and
Mg:
12C + 12C −→ 20Ne + 4He + 4.62MeV,
12C + 12C −→ 23Na + p + 2.24MeV,
12C + 12C −→ 24Mg + γ − 2.60MeV.
Aluminium can then be produced by:
24Mg + p −→ 25Al + γ.
The combustion reaction of oxygen is a dual-channel
process and causes the presence of Al, S, P, Si and
Mg. One of the channels is:
16O + 16O −→ 30Si + 1H + 1H + 0.39MeV,
16O + 16O −→ 24Mg + 4He + 4He − 0.39MeV,
∗nondanone@gmail.com
20
Advances in Astronomy and Space Physics I. O.Kushniruk, Ya.V. Pavlenko, J. S. Jenkins, H.R.A. Jones
16O + 16O −→ 27Al + 4He + 1H − 1.99MeV,
With continuous temperature growth, silicon burn-
ing is initiated. This process is described by a num-
ber of reactions. As a result we can receive, for ex-
ample, Ar, Ni, S, etc. 56Ni, after two β decays, turns
into 56Fe. It is the �nal stage of the fusion of nuclides
in massive stars, which forms the nucleus of the iron
group.
The production of heavy elements is provided
by other mechanisms. They are called s- and r-
processes. An s-process, or slow neutron capture, is a
formation of heavier nuclei by lighter nuclei through
successive neutron capture. The original element in
the s-process is 56Fe. The reaction chain ends with
209Bi. It is thought that s-processes occur mostly
in stars on the asymptotic giant branch. For the
s-process to run, an important condition is the abil-
ity to produce neutrons. The main neutron source
reactions are:
13C + 4He −→ 16O + n,
22Ne + 4He −→ 25Mg + n.
An examples of an s-process reaction is:
56Fe+ n −→ 57Fe+ n −→ 58Fe+ n −→ 59Fe
β−
−→
−→59Co+ n −→ 60Co
β−
−→ 60Ni+ n−→ . . .
Elements heavier than H and He are usually
called metals in astrophysics. Their concentration is
signi�cantly lower relative to hydrogen and helium,
however, they are the source of thousands of spec-
tral lines originating from a star's atmosphere. The
abundance of iron depends on a star's age and its
position in the galaxy [9]. Metal-rich stars are also
known to be rich in orbiting giant exoplanets. High
metallicity appears to be a major ingredient in the
formation of planets through core accretion [5].
HD77338 is one of the most metal-rich stars in
the sample of [3] and in the local Solar neighbour-
hood in general. Its spectral type is given as K0IV
in the Hipparcos Main Catalogue [17]. However,
HD77338 is not a sub-giant, as labelled in Hipparcos
[5], its mass and radius are smaller than those of the
Sun: M = 0.93 ± 0.05M�, R = 0.88 ± 0.04R�. A
parallax of 24.54± 1.06mas for HD77338 means the
star is located at a distance of 40.75 ± 1.76pc. Its
e�ective temperature and surface gravity were found
Teff = 5370 ± 80K, log g = 4.52 ± 0.06 [5]. More
stellar parameters for HD77338 and detailed infor-
mation about its planetary system are in [5].
Using the Simbad database one can �nd informa-
tion on the previous assessments of abundances in
the atmosphere of HD77338 (see Table 1). In most
cases the authors only determine the metallicity of
the star, i. e. the iron abundance. In turn, we recom-
puted the abundances of many elements which show
signi�cant absorption lines in the observed spectrum
of HD77338.
Table 1: Simbad's list of previous assessments of abun-
dances in the atmosphere of HD77338
Teff log g [Fe/H] Comp. star Ref.
5300 4.30 0.36 Sun [18]
5290 4.90 0.22 Sun [1]
5290 4.60 0.30 Sun [19]
the observations
The observations of HD77338 were carried out
as part of the Calan-Hertfordshire Extrasolar Planet
Search (CHEPS) program [4]. The main aim of the
program is monitoring a sample of metal-rich stars
in the southern hemisphere to search for short pe-
riod planets that have a high probability to transit
their host stars, along with improving the existing
statistics for planets orbiting solar-type and metal-
rich stars. The high-S/N (> 50) and high-resolution
(R = 100 000) spectrum of HD77338, observed with
the HARPS spectrograph [10], was reduced using the
standard automated HARPS pipeline and analysed
in this work in order to determine the chemical abun-
dances and other physical parameters of the stellar
atmosphere.
the procedure
Firstly, we selected �good� absorption lines for
all elements of interest that are present in spec-
tra of the Sun and HD77338. These lines should
not be blended (see [3]) and be intense enough in
both spectra. We selected lists of lines of each ele-
ment that were to be used for the abundance inves-
tigations. We used line list data, which was taken
from a database of atomic absorption spectra VALD
[7], to compute synthetic spectra of the Sun for
a plane-parallel model atmosphere with parameters
Teff/ log g/[Fe/H] = 5777/4.44/0.0 [15]. The model
atmosphere was used to compute the synthetic spec-
tra using WITA6 [13], building a grid of models with
di�erent microturbulent velocities Vt = 0 − 3 km/s
with a step size of 0.25 km/s. The shapes of the line
absorption pro�les were constructed as Voigt func-
tion pro�les H(a, v), and a classical approach was
used to compute the damping e�ects [20]. To com-
pute the rotational pro�le we followed the procedure
described in Gray [2].
All abundance determinations were performed by
the ABEL8 code [14]. Details of the full procedure
used are described in [16], see [3], also for more de-
tails on the line selection and �tting procedure.
21
Advances in Astronomy and Space Physics I. O.Kushniruk, Ya.V. Pavlenko, J. S. Jenkins, H.R.A. Jones
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
5780 5781 5782 5783 5784 5785 5786
R
es
id
ua
l F
lu
x
Wavelength (A)
Fig. 1: The dotted line represents the observed spec-
trum of the Sun, the solid line is the observed spectrum
of HD77338, the dashed line shows the synthetic spec-
trum computed by Wita618 with log N(Cr) = −6.11 for
a model atmosphere of 5315/4.39. This plot was used
to detect �clean� parts of Cr line pro�les marked here by
arrows.
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
5780 5781 5782 5783 5784 5785 5786
R
es
id
ua
l F
lu
x
Wavelength (A)
Fig. 2: Cr i absorption line pro�les computed for a model
atmosphere of 5315/4.39 and log N(Cr) = −6.09 using
ABEL8 and �tted to the observed spectrum of HD77338
shown by dashed and solid lines, respectively. The verti-
cal lines show the �tted parts of Cr sc i line pro�les.
results
the sun
The solar spectrum is well-studied, and abun-
dances for the Sun are known to very high accuracy;
therefore it represents a very good template. Fig. 1
and Fig. 2 illustrate the presence of spectral lines of
Cr in the observed spectrum of the Sun as a star [8].
Arrows on the plot show the spectral range which
was selected to compute pro�les of two Cri lines to
be used later by ABEL8 [14] in the determination of
the abundance of chromium. We employ a similar
selection in the solar spectrum Sun, and in the spec-
trum of HD77338 for lines of Fe i, Si i, Ni i, Ti i, Na i,
Mg i, Cu i, Zn i, Mn i, Cr i, Al i, and Ca i.
We veri�ed whether our input data were of suf-
�cient quality and quantity to reproduce the abun-
dances in the atmosphere of the Sun. We computed
abundances for the Sun using the �ts of the theoret-
ical spectra to the pro�les of the selected lines. In
that way we can test our method and estimate the
accuracy of our abundance determination. Then, we
investigated the dependence Ea = ∂a/∂E′′, where a
and E′′ are the iron abundance and excitation poten-
tial of the corresponding radiative transition forming
the absorption line. Best �ts of the selected lines of
Fe i in the computed spectra, when compared to their
observed pro�les in the solar spectrum, provide the
min Ea of Vt = 0.75 km/s. The abundances of iron
and other elements were then obtained using this
adopted value for the microturbulence; the results
are shown in Table 2. It is worth noting that our
abundances agree with the reference values within
an accuracy of ±0.1 dex.
hd 77338
The model atmosphere for HD77338 was com-
puted using the parameters determined by Jenkins et
al. [5] using the SAM12 code [15]. Again, as the �rst
step of our analysis, we determined the microturbu-
lent velocity in the atmosphere of HD77338. The
minimum of the slope of Ea provides Vt = 0.75 km/s
for log N(Fe) = −4.120 ± 0.07 or [Fe/H] = 0.281
(iteration 1). For other elements we used the same
value (Vt = 0.75 km/s).
We carried out 4 iterations to determine all abun-
dances. In each next step the abundances from
the previous determination were used to recompute
the model atmosphere by SAM12 [15] and the syn-
thetic spectra. Each time we are approaching self-
consistency by computing the model atmosphere
that relates to the �nal metallicity of the star.
In Table 2 we present our results for 12 di�erent
ionic species. We compare our abundances with the
solar values, obtained using a model atmosphere of
5777/4.44/0.00. They are in good agreement with
each other. Fig. 2 and Fig. 3 show the line pro�les of
Cr and Mg calculated using a Vt = 0.75 km/s.
In Fig. 4 we show the dependence of [X/H] on
atomic number of each element for every iteration.
The presence of errors can be explained by the pres-
ence of noise in the selected spectral lines, along with
only having a small number of lines to work with
for some elements. In Fig. 5 we present the depen-
dence of [X/Fe] for the �nal iteration, where di�erent
elements are shown using di�erent plotting shapes,
depending on their mechanism of formation.
22
Advances in Astronomy and Space Physics I. O.Kushniruk, Ya.V. Pavlenko, J. S. Jenkins, H.R.A. Jones
Table 2: Abundances in the atmosphere of HD77338, iteration 4.
Iron logN(X) logN(X)�, ABEL8 logN(X)� [X/H] [X/Fe] v sin i, km/s Nl
Al i −5.403± 0.000 −5.767± 0.033 −5.551 +0.148 −0.095 2.33± 0.44 3
Ca i −5.376± 0.029 −5.588± 0.023 −5.661 +0.285 +0.042 1.25± 0.13 14
Cr i −6.085± 0.032 −6.345± 0.026 −6.441 +0.356 +0.113 1.91± 0.14 22
Cu i −7.670± 0.058 −8.133± 0.067 −7.941 +0.271 −0.028 2.17± 0.44 3
Fe i −4.158± 0.038 −4.439± 0.023 −4.401 +0.243 +0.000 2.06± 0.11 27
Mg i −4.228± 0.058 −4.367± 0.095 −4.441 +0.213 −0.030 1.50± 0.50 3
Mn i −5.957± 0.097 −6.600± 0.046 −6.641 +0.684 +0.441 2.69± 0.21 8
Na i −5.387± 0.048 −5.789± 0.054 −5.721 +0.334 +0.091 1.94± 0.31 9
Ni i −5.367± 0.033 −5.756± 0.027 −5.821 +0.454 +0.211 2.29± 0.15 17
Si i −4.111± 0.054 −4.469± 0.058 −4.401 +0.290 +0.047 2.39± 0.13 23
Ti i −6.897± 0.040 −7.064± 0.028 −6.981 +0.084 −0.159 1.88± 0.13 24
Zn i −7.028± 0.065 −7.375± 0.048 −7.441 +0.413 +0.170 2.25± 0.25 4
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
5710.7 5710.8 5710.9 5711 5711.1 5711.2 5711.3 5711.4 5711.5
R
es
id
ua
l F
lu
x
Wavelength (A)
Fig. 3: Computed by ABEL8 and observed line pro-
�les of Mg in the spectrum of HD77338 with a model
atmosphere of 5315/4.39, logN(Mg) = −4.23 shown by
dashed and solid lines, respectively. The vertical lines
show the �tted part of Mgi line pro�le.
discussion
We determined abundances for 12 ionic species in
the atmosphere of the Sun and the metal-rich exo-
planet host star HD77338. Our values for the solar
abundances are in good agreement with results from
previous authors, proving the validity of our method.
We used the solar spectrum as a reference to select
the proper list of absorption lines to be used later in
the analysis of the HD77338 spectrum.
Our [X/H] correlates well with the condensation
temperature of the ions (Tcond), see discussion in [11].
This may indicate the presence of a common shell (in
the past) and can be an additional criterion for the
existence of a planetary system around metal-rich
stars.
We also computed v sin i for both stars. It is
worth noting that we determined all parameters in
the framework of a fully self-consistent approach (see
[15] for more details). In general, lines of Mn, Cu can
not be used to obtain v sin i because these lines usu-
ally have several close components, but in our case
the parameter v sin i was used to adjust theoretical
pro�les to get the proper �ts to the observed special
features. We believe that �ts to Fe i lines provide
reasonable measures of the rotational velocity.
Our results show that the abundances of most el-
ements in the atmosphere can be described well by
the overall metallicity. However, we found an over-
abundance of some of the iron peak elements (e. g.
Mn, Cu). Interestingly, Cu is an element formed
through the s-process and its abundance follows that
of Fe, whereas Zn and elements formed through the
p-process, e. g. Ni1, show a noticeable overabun-
dance compared to iron. It would be interesting to
compare these results for HD77338 with other metal
rich stars to see if this is a common trend for super
metal-rich stars. We plan to investigate this issue in
a following paper (Ivanyuk et al. 2015, in prepara-
tion).
acknowledgement
JSJ acknowledges the support of the Basal-CATA
grant. YP's work has been supported by an FP7
POSTAGBinGALAXIES grant (No. 269193; Inter-
national Research Sta� Exchange Scheme). Authors
thank the compilers of the international databases
used in our study: SIMBAD (France, Strasbourg),
VALD (Austria, Vienna), and the authors of the at-
las of the spectrum of the Sun as a star. We thank
the anonymous Referee for some reasonable remarks
and helpful comments.1see http://www.mao.kiev.ua/staff/yp/TXT/prs.png
23
Advances in Astronomy and Space Physics I. O.Kushniruk, Ya.V. Pavlenko, J. S. Jenkins, H.R.A. Jones
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
[X
/H
]
Atomic Number
Al Ca Cr CuFeMg MnNa NiSi Ti Zn
Fig. 4: Dependence of [X/H] on atomic number of each
element for HD 77338. Open circles show values found in
the �rst iteration, �lled circles are for iteration 2, open
squares are for iteration 3, and �nally the stars show the
results for iteration 4.
-0.2
-0.1
0
0.1
0.2
0.3
0.4
0.5
10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
[X
/F
e]
Atomic Number
Al Ca Cr CuFeMg MnNa NiSi Ti Zn
Fig. 5: Dependence of [X/Fe] on the atomic number of
each element. The di�erent plotting shapes represent the
di�erent formation mechanism of each element. Open
circles are for α-elements, diamonds show the thermonu-
clear elemental production, and s-process is shown by
triangles.
references
[1] Feltzing S. & GustafssonB. 1998, A&AS, 129, 237
[2] GrayD. F. 1976, `The observation and analysis of stellar
photospheres', Wiley-Interscience, New York
[3] Jenkins J. S., JonesH.R.A., PavlenkoY. et al. 2008,
A&A, 485, 571
[4] Jenkins J. S., JonesH.R.A., Go¹dziewskiK. et al. 2009,
MNRAS, 398, 911
[5] Jenkins J. S., JonesH.R.A., TuomiM. et al. 2013, ApJ,
766, 67
[6] Jenkins J. S., JonesH.R.A., RojoP. et al. 2013, EPJ
Web of Conferences 47, 05001
[7] KupkaF., PiskunovN., RyabchikovaT.A., Stem-
pelsH.C. & WeissW.W. 1999, A&AS, 138, 119
[8] KuruczR. L., Furenlid I., Brault J. & TestermanL. 1984,
`Solar �ux atlas from 296 to 1300 nm', National Solar
Observatory, New Mexico
[9] LyubimkovL. S. 1995, `Chemical composition of stars:
method and result of analysis', Astroprint, Odesa
[10] MayorM., Udry S., NaefD. et al. 2004, A&A, 415, 391
[11] Meléndez J., AsplundM., GustafssonB. & YongD. 2009,
ApJ, 704, L66
[12] MisheninaT.V., KovtyukhV.V., SoubiranC., Trava-
glioC. & BussoM. 2002, A&A, 396, 189
[13] PavlenkoYa.V. 1997, Astrophys. and Space Science,
253, 43
[14] PavlenkoYa.V. 2002, Kinematika i Fizika Nebesnykh
Tel, 18, 1, 48
[15] Pavlenko Ya.V. 2003, Astron. Rep., 47, 59
[16] PavlenkoYa.V., Jenkins J. S., JonesH.R.A., IvanyukO.
& Pin�eldD. J. 2012, MNRAS, 422, 542
[17] PerrymanM.A.C., BrownA.G.A., LebretonY. et al.
1997, A&A, 331, 81
[18] Prugniel Ph., Vauglin I. & KolevaM. 2011, A&A, 531,
A165
[19] ThorénP. & Feltzing S. 2000, A&A, 363, 692
[20] UnsoldA. 1956, `Physics der Sternatmospharen', Amer-
ican Institute of Physics, NY
24
|