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J/AJ/106/1059       Lithium in the Pleiades      (Soderblom+, 1993)

The evolution of the lithium abundances of solar-type stars. III. The Pleiades Soderblom D.R., Jones B.F., Balachandran S., Stauffer J.R., Duncan D.K., Fedele S.B., Hudon J.D. <Astron. J. 106, 1059 (1993)> =1993AJ....106.1059S (SIMBAD/NED Reference)
ADC_Keywords: Abundances ; Clusters, open Abstract: We report new measurements of lithium in more than 100 Pleiades F, G, and K dwarfs. Abundances were determined from spectrum synthesis fits to the data as well as from use of new curves of growth for the Li 6708 A feature (presented in an Appendix). We confirm the intrinsic spread in lithium abundance within the Pleiades seen by Duncan & Jones (1983ApJ...271..663D), but we establish more observational constraints on Li in this cluster: First, for stars near 1.0Msun [about 0.60 to 0.75 in (B-V)0], the scatter in the relation between log N(Li) (defined as N(Li)) and T(eff) is consistent with our observational uncertainty. That means that most late-F and early-G dwarfs in the Pleiades are consistent with the tight N(Li) versus mass relation seen in the Hyades in the same mass range. Second, at (B-V)0∼0.8 (M∼0.9Msun), large and real star-to-star differences in N(Li) appear. The range in N(Li) at (B-V)0∼0.8 is about 1dex, and grows to as much as 1.5dex for less massive stars. Third, the most Li-rich stars have abundances at or near the primordial level for Population I (N(Li)∼3.2), and none exceed that level by a significant amount. Fourth, at any given color the stars that rotate fastest have the most Li and have the strongest chromospheric activity. We consider the ways in which an apparent spread in N(Li) could arise from an intrinsically tight N(Li)-mass relation and conclude that the spread is probably real and is not an artifact of line formation conditions or inhomogeneous atmospheres on the stars. It is possible to produce large apparent changes in N(Li) by covering a significant fraction of a star's surface with cooler regions ("spots"), but doing so has other ramifications that conflict with the observations. Some current models lead to a spread in N(Li) in which the fastest rotators (those that have lost the least angular momentum) have the most Li, and that mechanism may account for what is seen. A comparison of the Pleiades to the Alpha Persei cluster shows that most Alpha Persei stars have Li abundances comparable to their Pleiades counterparts, but there is a significant fraction (about 30%) of Alpha Persei stars that lie below the Pleiades in N(Li) by 1dex or more. Some of these anomalous stars have even less Li than Hyades stars of the same T(eff). If these stars are bona fide Alpha Persei members (and they probably are), their Li abundances strain our understanding of Li depletion. The Pleiades, considered together with Alpha Persei and the Hyades, shows that stars with [Fe/H]≥0.0 and which are more massive than about 1.25Msun do not deplete Li prior to reaching main the sequence. Moreover, solar-abundance stars ([Fe/H]∼0.0) with M≳1.1Msun do not experience pre-main-sequence depletion either. Pleiades dwarfs near T(eff)=6700K show evidence of being depleted in Li, indicating that an incipient Li "chasm" is present even at an age of 70Myr. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1 79 131 Observations of Lithium in Pleiades F, G, and K dwarfs table2 85 61 *Lithium abundances for the 6708 A feature table3 85 51 *Lithium abundances for the 6104 A feature
Note on table2, table3: A grid of curves of growth was computed for every 250K in T(eff) from 4000 to 6500K, and for every 0.2dex in logN(Li). A microturbulent velocity of 1.0km/s was used for the tables given here, but computations for Xi=2km/s differ little. One dimensional interpolation was done to create points evenly spaced in log W(lambda) with log N(Li) as the dependent variable.
Byte-by-byte Description of file: table1
Bytes Format Units Label Explanations
1- 4 A4 --- fgk fgk number from Soderblom et al. (1993ApJS...85..315S) (hereafter SSHJ) 6- 9 A4 --- name Hertzsprung (H II) designation. A "P" prefix denotes a Pels star. 11- 16 A6 --- Sp Spectral type 17- 21 F5.3 mag (B-V)0 Dereddened (B-V) 22 A1 --- u_(B-V)0 Uncertainty flag on (B-V)0 24- 27 I4 K Teff Effective temperature 29 A1 --- l_vsini Limit flag on vsini 30- 34 F5.1 km/s vsini ? Rotational velocity 35 A1 --- u_vsini uncertainty flag on vsini 36 A1 --- n_vsini [S ] 'S' indicating a double-lined spectroscopic binary whose vsini values are given in table2 of SSHJ (SB2). 38- 42 F5.2 --- log(RHalpha) []? Ratio of the Halpha flux to the stellar bolometric flux, log R(Halpha) from SSHJ 44- 48 F5.2 --- log(R8542) []? Ratio of the 8542 A Ca II line flux to the stellar bolometric flux, logR(8542) from SSHJ 51- 53 I3 0.1pm W7699 []? Equivalent width of K I 7699A line 56- 58 I3 0.1pm W6717 []? Equivalent width of Ca I 6717 A line 59 A1 --- n_W6717 Note on W6717. See note (1) 60 A1 --- l_W6708 Limit flag on W6708 61- 63 I3 0.1pm W6708 Equivalent width of Li I 6708 A line, corrected for Fe I 6707.441. 64 A1 --- u_W6708 Uncertainty flag on W6708 65 A1 --- n_W6708 Note on W6708. See note (1) 67- 72 A6 --- q Source and quality code (2) 73 A1 --- l_log(N(Li)) Limiting character for lithium abundance 75- 78 F4.2 --- log(N(Li)) Abundance of lithium (scale logN(H)=12) 79 A1 --- u_log(N(Li)) Uncertainty flag on log(N(Li))
Note (1): A '*' indicates that equivalent width of the line has been compensated for spectrum dilution by the following factors: H II 102, 1.33; H II 173, 1.40; H II 248 and 2147, 1.20; H II 298, 571, 1100, and 2406, 1.10; H II 320, 1.15; H II 1101, 1.25. Note (2): Source and quality code: Bo = Boesgaard et al. 1988b, =1988ApJ...327..389B Bu = Butler et al. 1987, =1987ApJ...319L..19B P = Pilachowski et al. 1987, =1987PASP...99.1288P Codes a to d denote Lick data and are in descending order of quality, with approximate uncertainties of 12, 18, 25, and 40 mA, respectively
Byte-by-byte Description of file: table2 table3
Bytes Format Units Label Explanations
4- 7 F4.2 [0.1pm] log(W6708) Equivalent width of Li 6708 line 10- 15 F6.3 --- logN(Li)1 Li abundance for Teff = 4000 K 17- 22 F6.3 --- logN(Li)2 Li abundance for Teff = 4250 K 24- 29 F6.3 --- logN(Li)3 Li abundance for Teff = 4500 K 31- 36 F6.3 --- logN(Li)4 []? Li abundance for Teff = 4750 K 38- 43 F6.3 --- logN(Li)5 []? Li abundance for Teff = 5000 K 45- 50 F6.3 --- logN(Li)6 []? Li abundance for Teff = 5250 K 52- 57 F6.3 --- logN(Li)7 []? Li abundance for Teff = 5500 K 59- 64 F6.3 --- logN(Li)8 []? Li abundance for Teff = 5750 K 66- 71 F6.3 --- logN(Li)9 []? Li abundance for Teff = 6000 K 73- 78 F6.3 --- logN(Li)10 []? Li abundance for Teff = 6250 K 80- 85 F6.3 --- logN(Li)11 []? Li abundance for Teff = 6500 K
Origin: AAS CD-ROM series, Volume 1, 1993
(End) Patricia Bauer [CDS] 12-Sep-1994
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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