J/AJ/164/255 Chemical abundances in open cluster Stock 2 (Casamiquela+, 2022)
Chemically Peculiar Stars in the Open Cluster Stock 2.
Casamiquela L., Gebran M., Agueros M.A., Bouy H., Soubiran C.
<Astron. J., 164, 255 (2022)>
=2022AJ....164..255C 2022AJ....164..255C
ADC_Keywords: Clusters, open; Stars, A-type; Abundances; Spectra, optical;
Spectra, infrared; Effective temperatures
Keywords: A stars ; Open star clusters ; Chemical abundances ;
Chemically peculiar stars
Abstract:
The recently rediscovered open cluster Stock2, located roughly 375pc
away and about 400Myr old, has the potential to be an exciting new
testbed for our understanding of stellar evolution. We present results
from a spectroscopic campaign to characterize stars near the cluster's
main-sequence turnoff; our goal is to identify candidate chemically
peculiar stars among the cluster's A-stars. We obtained echelle
spectra for 64 cluster members with ESPaDOnS on the 3.6m
Canada-France-Hawaii Telescope, Maunakea Observatory, USA, and for six
stars with SOPHIE on the 1.93m telescope at the Observatoire de
Haute-Provence, France. We complemented these new observations with
those of 13 high-mass cluster members from the HARPS-N archive; our
overall sample is of 71 stars. We derived the fundamental parameters
(Teff, logg, [M/H]) as well as vesini for our sample using the
sliced inverse regression technique, and then used iSpec to derive
individual abundances of 12 chemical species. With these abundance
determinations, we identified nine A-stars with anomalous levels of
Sc, Ca, and other metallic lines. Follow-up observations of these Am
candidates with a known age can transform them into benchmarks for
evolutionary models that include atomic diffusion and help build a
better understanding of the complex interactions between macroscopic
and microscopic processes in stellar interiors.
Description:
During the 2020B semester, we observed 64 hot Stock 2 MS-stars with
the ESPaDOnS spectrograph mounted on the 3.6m Canada-France-Hawaii
telescope located at the Maunakea Observatory, USA (PI:Casamiquela,
ID:20BF003). We used the Star+Sky mode, which gives a full optical
spectrum (3700-10500Å) with a mean resolution R=68000.
We complemented these observations with those of six MS-stars
re-observed on the night of 2022 February 8 using the SOPHIE
spectrograph, a cross-dispersed echelle spectrograph mounted on the
1.93m telescope of the Observatoire de Haute-Provence, France
(PI:Bouy, ID:21B.PNPS.BOUY). We used the High Efficiency mode, leading
to spectra over the wavelength range 3870-6940Å in 39 orders with
R=40000.
Finally, we analyzed the spectra of 13 MS-stars using the HARPS-N
echelle spectrograph mounted on the 3.6m Telescopio Nazionale Galileo
at El Roque de los Muchachos Observatory, Spain. These spectra cover
the wavelength range ∼4000-7000Å with R=115000.
Objects:
-----------------------------------------------
RA (2000) DE Designation(s)
-----------------------------------------------
02 15 25.44 +59 31 19.1 Stock 2 = C 0211+590
-----------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2.dat 183 83 Atmospheric parameters and abundances of the
analyzed spectra
--------------------------------------------------------------------------------
See also:
VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)
J/A+A/475/1053 : Magnetic fields in Ap/Bp stars (Auriere+, 2007)
J/A+A/523/A91 : CoRoT/Exoplanet fields with MATISSE (Gazzano+, 2010)
J/A+A/523/A71 : A and F stars abundances in the Hyades (Gebran+, 2010)
J/A+A/573/A67 : Fundamental stellar parameters from PolarBase (Paletou+, 2015)
J/A+A/589/A83 : PCA-based inversion of stellar parameters (Gebran+, 2016)
J/A+A/616/A10 : 46 open clusters GaiaDR2 HRdiagrams (Gaia Collaboration, 2018)
J/ApJ/879/100 : K2 rotation periods Hyades & Praesepe members (Douglas+, 2019)
J/MNRAS/485/3623 : Red giants abundance analysis open clusters (Reddy+, 2019)
J/A+A/640/A1 : Portrait Galactic disc (Cantat-Gaudin+, 2020)
J/A+A/635/A8 : Differential abundances of open clusters (Casamiquela+, 2020)
J/A+A/645/A106 : Atomic data for the Gaia-ESO Survey (Heiter+, 2021)
J/A+A/661/A147 : Galac. interstellar dust Gaia-2MASS 3D maps (Lallement+, 2022)
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 18 I18 --- Gaia Gaia DR2 identifier
20- 27 A8 --- Inst Instrument identifier (1)
29- 30 I2 --- S/N [30/94] Spectrum signal-to-noise ratio
32- 39 F8.3 K Teff [7176/9971] Effective temperature
41- 45 F5.3 [cm/s2] logg [2.65/4.95] log surface gravity
47- 53 F7.3 km/s vsini [6.25/282] Projected rotational velocity
from SIR
55- 59 F5.2 [Sun] [Fe/H] [-0.22/0.35]? iSpec Fe abundance relative to
the Sun
61- 64 F4.2 [Sun] e_[Fe/H] [0.04/0.37]? Uncertainty in [Fe/H]
66- 70 F5.2 [Sun] [Ti/H] [-0.29/0.42]? iSpec Ti abundance relative to
the Sun
72- 75 F4.2 [Sun] e_[Ti/H] [0.04/0.3]? Uncertainty in [Ti/H]
77- 81 F5.2 [Sun] [Cr/H] [-0.11/0.72]? iSpec Cr abundance relative to
the Sun
83- 86 F4.2 [Sun] e_[Cr/H] [0.02/0.4]? Uncertainty in [Cr/H]
88- 91 F4.2 [Sun] [Si/H] [0/1.04]? iSpec Si abundance relative to
the Sun
93- 96 F4.2 [Sun] e_[Si/H] [0.01/0.4]? Uncertainty in [Si/H]
98-102 F5.2 [Sun] [O/H] [-0.68/1.79]? iSpec O abundance relative to
the Sun
104-107 F4.2 [Sun] e_[O/H] [0.1/0.7]? Uncertainty in [O/H]
109-113 F5.2 [Sun] [Mg/H] [-0.12/1.08]? iSpec Mg abundance relative to
the Sun
115-118 F4.2 [Sun] e_[Mg/H] [0.08/0.4]? Uncertainty in [Mg/H]
120-124 F5.2 [Sun] [Ca/H] [-0.73/0.77]? iSpec Ca abundance relative to
the Sun
126-129 F4.2 [Sun] e_[Ca/H] [0/0.8]? Uncertainty in [Ca/H]
131-135 F5.2 [Sun] [Y/H] [-0.06/2.11]? iSpec Y abundance relative to
the Sun
137-140 F4.2 [Sun] e_[Y/H] [0/0.5]? Uncertainty in [Y/H]
142-146 F5.2 [Sun] [Sc/H] [-1.65/0.42]? iSpec Sc abundance relative to
the Sun
148-151 F4.2 [Sun] e_[Sc/H] [0/0.5]? Uncertainty in [Sc/H]
153-156 F4.2 [Sun] [Ba/H] [0.15/1.13]? iSpec Ba abundance relative to
the Sun
158-161 F4.2 [Sun] e_[Ba/H] [0.03/0.5]? Uncertainty in [Ba/H]
163-167 F5.2 [Sun] [Zr/H] [-0.35/1.21]? iSpec Zr abundance relative to
the Sun
169-172 F4.2 [Sun] e_[Zr/H] [0.01/0.5]? Uncertainty in [Zr/H]
174-178 F5.2 [Sun] [Sr/H] [-0.98/0.86]? iSpec Sr abundance relative to
the Sun
180-183 F4.2 [Sun] e_[Sr/H] [0.09/0.6]? Uncertainty in [Sr/H]
--------------------------------------------------------------------------------
Note (1): Instruments as follows:
SOPHIE = The SOPHIE spectrograph, a cross-dispersed echelle spectrograph
mounted on the 1.93m telescope of the Observatoire de Haute
Provence, France with the High Efficiency mode. IN the wavelength
range 3870-6940Å in 39 orders with R=40000 (6 occurrences).
HARPS = The HARPS-N echelle spectrograph mounted on the 3.6m
Telescopio Nazionale Galileo at El Roque de los Muchachos
Observatory, Spain. These spectra cover the wavelength
range ∼4000-7000Å with R=115000 (13 occurrences).
ESPADONS = The ESPaDOnS spectrograph mounted on the 3.6m
Canada-France-Hawaii telescope (CFHT) located at the Mauna Kea
Observatory, USA with the Star+Sky mode. This gives a full
optical spectrum (3700-10500Å) with a mean resolution
R=68000 (64 occurrences).
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 03-Feb-2023