J/AJ/105/2299 Li abundance of solar-type stars. II. (Soderblom+, 1993)
The evolution of the lithium abundances of solar-type stars.
II. The Ursa Major group
SODERBLOM D.R., PILACHOWSKI C.A., FEDELE S.B., JONES B.F.
<Astron. J. 105, 2299 (1993)>
=1993AJ....105.2299S 1993AJ....105.2299S (SIMBAD/NED Reference)
ADC_Keywords: Stars, G-type; Stars, dwarfs; Combined data; Abundances
Abstract:
We draw upon a recent study of the membership of the Ursa Major Group
(UMaG) to examine lithium among 0.3 Gyr old solar-type stars. For most
G and K dwarfs, Li confirms the conclusions about membership in UMaG
reached on the basis of kinematics and chromospheric activity. G and K
dwarfs in UMaG have less Li than comparable stars in the Pleiades.
This indicates that G and K dwarfs undergo Li depletion while they are
on the main sequence, in addition to any pre-main-sequence depletion
they may have experienced. Moreover, the Li abundances of the Pleiades
K dwarfs cannot be attributed to main-sequence depletion alone,
demonstrating that pre-main-sequence depletion of Li also takes place.
The Sun's Li abundance implies that the main-sequence mechanism
becomes less effective with age, otherwise the Sun would have even less
Li than it does. The hottest stars in the UMaG (T(eff) ≳ 6800K) have
Li abundances like those of hot stars in the Pleiades and Hyades and in
T Tauris, and the two genuine UMaG members with temperatures near
Boesgaard's Li chasm have Li abundances consistent with that chasm
developing fully by 0.3 Gyr for stars with UMaG's metallicity
([Fe/H] = -0.08 ± 0.09). We see differences in the abundance of Li
between UMaG members of the same spectral types, indicating that a real
spread in the lithium abundance exists within this group.
File Summary:
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File Name Lrecl Records Explanations
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ReadMe 80 . This file
table1 88 46 Lithium abundances of UMaG solar-type stars
table2 58 36 *Colors and temperatures of UMaG candidates
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Note on table2: The photometry has been taken from Nicolet (1978),
Hauck & Mermilliod (1980) and Mendoza (1967). Note that no corrections for
reddening have been made for these nearby (d ≤ 25 pc) stars.
Byte-by-byte Description of file: table1
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Bytes Format Units Label Explanations
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1 A1 --- Member [abc] Membership probability as:
a: Probable member
b: Possible member
c: Probable non-member
2- 7 I6 --- HD Henry Draper number
8- 9 A2 --- m_HD Multiplicity index on HD number
11- 14 I4 --- HR []? Harvard Revised (Brigth Star) number
15- 16 A2 --- m_HR Multiplicity index on HR number
18- 28 A11 --- Name Other name
30- 33 A4 --- Sp Spectral type
36- 39 F4.2 mag B-V (B-V) color
40 A1 --- u_B-V Uncertainty flag on B-V
41- 45 I5 K Teff Effective temperature (average of the
temperatures listed in table2)
46 A1 --- u_Teff Uncertainty flag on B-V
47 A1 --- l_W(Li)L limit flag on W(Li)L
48- 49 I2 0.1pm W(Li)L []? Measured equivalent width for Li 6708 A
feature from Lick Hamilton spectrograph
50 A1 --- u_W(Li)L uncertainty flag on W(Li)L
51 A1 --- l_W(Li)K limit flag on W(Li)K
52- 53 I2 0.1pm W(Li)K []? Measured equivalent width for Li 6708 A
feature from Kitt Peak
54 A1 --- u_W(Li)K uncertainty flag on W(Li)K
56 A1 --- l_W(Li)B limit flag on W(Li)B
57- 60 F4.1 0.1pm W(Li)B []? Measured equivalent width for Li 6708 A
feature from Boesgaard et al. (1988)
62- 63 I2 0.1pm W(Li)R []? Measured equivalent width for Li 6708 A
feature from Lick Reticon
66 A1 --- l_W(Li)E limit flag on W(Li)E
67- 68 I2 0.1pm W(Li)E []? Measured equivalent width for Li 6708 A
feature from ESO
70 A1 --- l_W(Li)I limit flag on W(Li)I
71 I1 0.1pm W(Li)I []? Equivalent width for Li 6708 A feature
(origin not precised)
77 A1 --- l_<W(Li)> limit flag on <W(Li)>
78- 79 I2 0.1pm <W(Li)> Adopted mean equivalent width
82 A1 --- l_log(N(Li)) limit flag on log(N(Li))
83- 87 F5.2 --- log(N(Li)) Log of the lithium abundance, log(N(Li)),
where log N(H) = 12
88 A1 --- u_log(N(Li)) Uncertainty flag on B-V
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Byte-by-byte Description of file: table2
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Bytes Format Units Label Explanations
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1- 6 I6 --- HD Henry Draper number
7- 8 A2 --- m_HD Multiplicity index on HD number
9- 14 F6.2 mag B-V (B-V) color
15- 20 I6 K Teff(B-V) Effective temperature inferred from (B-V)
21- 27 F7.3 mag b-y []? Stromgren color index (b-y)
28- 33 I6 K Teff(b-y) []? Effective temperature inferred from
color index (b-y)
34- 40 F7.3 mag Beta []? Stromgren beta index
41- 46 I6 K Teff(Beta) []? Effective temperature inferred from
beta index
47- 52 F6.2 mag V-I []? Johnson color index (V-I)
53- 58 I6 K Teff(V-I) []? Effective temperature inferred from
color index (V-I)
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References:
Hauck B. & Mermilliod M. 1980, A&AS, 40, 1
Mendoza E.E. 1967, Bol. Obs. Tonantzintla y Tacubaya, 4, 149
Nicolet B. 1978, A&AS, 34, 1
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Origin: AAS CD-ROM series, Volume 1, 1993
(End) Patricia Bauer [CDS] 06-Jul-1994