J/AJ/152/176 Abundances for all seven stars in Latham 1 (O'Connell+, 2016)
Chemical abundance analysis of moving group W11450 (Latham 1).
O'Connell J.E., Martens K., Frinchaboy P.M.
<Astron. J., 152, 176-176 (2016)>
=2016AJ....152..176O 2016AJ....152..176O (SIMBAD/NED BibCode)
ADC_Keywords: Associations, stellar ; Equivalent widths ; Abundances
Keywords: binaries: general - binaries: visual -
open clusters and associations: individual: (Group W11450,Latham 1) -
stars: abundances
Abstract:
We present elemental abundances for all seven stars in Moving Group
W11450 (Latham 1) to determine if they may be chemically related.
These stars appear to be both spatially and kinematically related, but
no spectroscopic abundance analysis exists in literature. Abundances
for eight elements were derived via equivalent width analyses of
high-resolution (R∼60000), high-signal-to-noise ratio (<S/N> ∼100)
spectra obtained with the Otto Struve 2.1m telescope and the Sandiford
Echelle Spectrograph at McDonald Observatory. The large star-to-star
scatter in metallicity, -0.55≤[Fe/H]≤0.06dex (σ=0.25),
implies these stars were not produced from the same chemically
homogeneous molecular cloud, and are therefore not part of a remnant
or open cluster as previously proposed. Prior to this analysis, it was
suggested that two stars in the group, W11449 and W11450, are possible
wide binaries. The candidate wide binary pair show similar chemical
abundance patterns with not only iron but with other elements analyzed
in this study, suggesting the proposed connection between these two
stars may be real.
Description:
Observations for all target stars were obtained at McDonald
Observatory with the Otto Struve 2.1m telescope instrumented with the
Sandiford Cass Echelle Spectrometer (SES;
R=λ/Δλ∼60000) in 2013 and 2014 June. The
spectrograph setup was centered near 6175Å in 2013 and 6375Å in
2014 with wavelength coverage spanning from ∼5350-6560Å and
∼5560-6750Å, respectively (see Table2 for observation dates and
exposure times).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 75 7 Observation logs, 2013 and 2014
table5.dat 73 68 Atomic data and equivalent widths
table6.dat 107 8 Measured abundances
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See also:
B/ocl : Optically visible open clusters and Candidates (Dias+ 2002-2015)
VI/135 : All-sky spectrally matched Tycho2 stars (Pickles+, 2010)
V/136 : Teff and metallicities for Tycho-2 stars (Ammons+, 2006)
I/259 : The Tycho-2 Catalogue (Hog+ 2000)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1 A1 --- --- [W]
2- 6 I5 --- Weistrop Weistrop identifier of the star (1)
8- 18 A11 --- Tycho2 Star identifier from Tycho-2 (Cat. I/259)
20- 36 A17 --- Date Date of observation
38- 39 I2 h RAh Hour of Right Ascension (J2000) (2)
41- 42 I2 min RAm Minute of Right Ascension (J2000) (2)
44- 49 F6.3 s RAs Second of Right Ascension (J2000) (2)
51 A1 --- DE- Sign of the Declination (2)
52- 53 I2 deg DEd Degree of Declination (J2000) (2)
55- 56 I2 arcmin DEm Arcminute of Declination (J2000) (2)
58- 62 F5.2 arcsec DEs Arcsecond of Declination (J2000) (2)
64- 68 F5.2 mag Vmag V-band magnitude (3)
70 I1 --- Nexp Number of exposures
72- 75 I4 s Exp Exposure time
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Note (1): Star Identifiers from the Weistrop catalog (1980; private
communication) used by Lathem et al. 1991AJ....101..625L 1991AJ....101..625L.
Note (2): Updated J2000 coordinates from SIMBAD astronomical database.
Note (3): Tycho-2 photometry is converted to the Johnson photometric system
(see Section 2 for specifics).
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 8 F8.3 0.1nm lambda Wavelength λ
10- 14 A5 --- Ion Species (either Ba II, Ca I, Fe I, Fe II, Mg I
Na I, Ni I, or Si I)
16- 20 F5.3 eV EP Excitation potential
22- 26 F5.2 --- loggf Log of the oscillator strength
28- 33 F6.2 0.1pm W11449 ? Equivalent width of the star W11449 (mÅ)
35- 40 F6.2 0.1pm W11450 ? Equivalent width of the star W11450 (mÅ)
42- 47 F6.2 0.1pm W12388 ? Equivalent width of the star W12388 (mÅ)
49- 54 F6.2 0.1pm W13284 ? Equivalent width of the star W13284 (mÅ)
56- 61 F6.2 0.1pm W21415 ? Equivalent width of the star W21415 (mÅ)
63- 67 F5.2 0.1pm W23375 ? Equivalent width of the star W23375 (mÅ)
69- 73 F5.2 0.1pm W23508 ? Equivalent width of the star W23508 (mÅ)
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- [X/Fe] Species
12- 16 F5.2 [Sun] W11449 Abundance for the star W11449
18- 21 F4.2 [Sun] e_W11449 Error in W11449
23- 24 I2 --- o_W11449 Number of absorption lines used for W11449
abundance analysis
26- 30 F5.2 [Sun] W11450 Abundance for the star W11450
32- 35 F4.2 [Sun] e_W11450 Error in W11450
37- 38 I2 --- o_W11450 Number of absorption lines used for W11450
abundance analysis
40- 44 F5.2 [Sun] W12388 Abundance for the star W12388
46- 49 F4.2 [Sun] e_W12388 Error in W12388
51- 52 I2 --- o_W12388 Number of absorption lines used for W12388
abundance analysis
54- 58 F5.2 [Sun] W13284 Abundance for the star W13284
60- 63 F4.2 [Sun] e_W13284 Error in W13284
65- 66 I2 --- o_W13284 Number of absorption lines used for W13284
abundance analysis
68- 72 F5.2 [Sun] W21415 Abundance for the star W21415
74- 77 F4.2 [Sun] e_W21415 Error in W21415
79- 80 I2 --- o_W21415 Number of absorption lines used for W21415
abundance analysis
82- 86 F5.2 [Sun] W23375 ? Abundance for the star W23375
88- 91 F4.2 [Sun] e_W23375 ? Error in W23375
93 I1 --- o_W23375 ? Number of absorption lines used for W23375
abundance analysis
95- 99 F5.2 [Sun] W23508 Abundance for the star W23508
101-104 F4.2 [Sun] e_W23508 Error in W23508
106-107 I2 --- o_W23508 Number of absorption lines used for W23375
abundance analysis
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History:
From electronic version of the journal
(End) Sylvain Guehenneux [CDS] 22-Mar-2017