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J/ApJ/687/1264      Age estimation for solar-type dwarfs     (Mamajek+, 2008)

Improved age estimation for solar-type dwarfs using activity-rotation diagnostics. Mamajek E.E., Hillenbrand L.A. <Astrophys. J., 687, 1264-1293 (2008)> =2008ApJ...687.1264M
ADC_Keywords: Stars, G-type ; Photometry ; Stars, ages Keywords: stars: activity - stars: chromospheres - stars: coronae - stars: fundamental parameters - stars: rotation - X-rays: stars Abstract: While the strong anticorrelation between chromospheric activity and age has led to the common use of the CaII H and K emission index (R'HK=LHK/Lbol) as an empirical age estimator for solar-type dwarfs, existing activity-age relations produce implausible ages at both high and low activity levels. We have compiled R'HK, data from the literature for young stellar clusters, richly populating for the first time the young end of the activity-age relation. Combining the cluster activity data with modern cluster age estimates and analyzing the color dependence of the chromospheric activity age index, we derive an improved activity-age calibration for F7-K2 dwarfs (0.5<B-V<0.9mag). We also present a more fundamentally motivated activity-age calibration that relies on conversion of R'HK values through the Rossby number to rotation periods and then makes use of improved gyrochronology relations. Description: We have collected R'HK indices derived from S-values in the tradition of the Mount Wilson HK project. The adopted solar data are: (B-V)0=0.65mag, Age=4.57Gyr, logR'HK=-4.906 File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table2.dat 58 21 logR'HK for color-separated solar-type dwarf binaries table3.dat 58 14 logR'HK for near-identical solar-type dwarf binaries table4.dat 57 5 Field binaries with rotation periods table5.dat 108 274 Members of stellar aggregates with logR'HK measurements table8.dat 32 23 Old solar-type dwarfs from Valenti et al. (2005, Cat. J/ApJS/159/141) with age uncertainties of <20% table12.dat 47 17 Activity-gyro ages for solar-type binaries table13.dat 110 103 Activity ages for the solar-type dwarfs within 16pc refs.dat 185 64 References and notes
Byte-by-byte Description of file: table[23].dat
Bytes Format Units Label Explanations
1- 10 A10 --- StarA Name of primary 12- 21 A10 --- StarB Name of secondary 24- 27 F4.2 mag B-V.A B-V colour index for A component 29- 32 F4.2 mag B-V.B B-V colour index for B component 34- 38 F5.2 --- logR'HKA R'HK index for A component 40- 44 F5.2 --- logR'HKB R'HK index for B component 46- 58 A13 --- Ref References, in refs.dat file (the '*' indicates values converted to logR'HK by the author following Noyes et al. (1984ApJ...279..763N))
Byte-by-byte Description of file: table4.dat
Bytes Format Units Label Explanations
1- 10 A10 --- StarA Name of primary 12- 21 A10 --- StarB Name of secondary 23- 26 F4.2 mag B-V.A B-V colour index for A component (1) 28- 31 F4.2 mag B-V.B B-V colour index for B component 33- 37 F5.2 d Per.A Period of A component 39- 43 F5.2 d Per.B Period of B component 45- 57 A13 --- Ref References, in refs.dat file
Note (1): The period for HD 128620 (alpha Cen A) is a mean (25.6days) from values given by E. Guinan (2008, priv. com.; 22±3days) and Hallam et al. (1991ApJ...372..610H; 28.8±2.5days) and is consistent within the constraints from vsini and p-mode rotational splitting (Fletcher et al. 2006MNRAS.371..935F; Bazot et al. 2007A&A...470..295B).
Byte-by-byte Description of file: table5.dat
Bytes Format Units Label Explanations
1- 17 A17 --- Name Name 18- 40 A23 --- SName Simbad Name 42- 51 A10 --- OName HD name 53- 56 F4.2 mag B-V ? B-V colour index 58- 59 I2 --- r_B-V ? Reference for B-V, in refs.dat file 61- 64 F4.2 mag E(B-V) Interstellar reddening 66- 71 A6 --- r_E(B-V) Reference for E(B-V), in refs.dat file 74- 77 F4.2 mag (B-V)0 Intrinsic B-V colour index 79- 84 A6 --- r_(B-V)0 Reference for (B-V)0, in refs.dat file 87- 91 F5.2 --- logR'HK R'HK index 93- 95 I3 --- o_logR'HK ? Number of measurements 97- 98 I2 --- r_logR'HK Reference for logR'HK, in refs.dat file 100-108 A9 --- Group Group name (1)
Note (1): the groups are (from table6 of paper): ----------------------------------------------------------------------- Group Age log RHK 68% N* Usual name Name Myr median ----------------------------------------------------------------------- US 5 -4.05±0.03 0.13 9 Upper Sco association beta Pic 12 -4.03±0.13 0.23 6 β Pic association UCL 16 -4.04±0.01 0.07 10 Upper Cen-Lup and Lower Cen-Cru Tuc 30 -4.16±0.13 0.16 8 Tuc-Hor association alpha Per 85 -4.16±0.08 0.27 13 α Per cluster Pleiades 130 -4.33±0.04 0.24 56 Pleiades cluster UMa 500 -4.48±0.03 0.09 17 UMa Group Hyades 625 -4.47±0.01 0.09 87 Hyades cluster M67 4000 -4.84±0.01 0.11 76 M67 open cluster -----------------------------------------------------------------------
Byte-by-byte Description of file: table8.dat
Bytes Format Units Label Explanations
1- 6 I6 --- HD HD number (Cat. III/135) 8- 12 F5.3 mag B-V B-V color from Perryman et al. (HIP, 1997, Cat. I/239) 14- 17 F4.1 Gyr tau Isochronal age (1) 19- 23 F5.2 --- logR'HK R'HK Chromospheric activity 25- 26 I2 --- r_logR'HK Reference for logR'HK, in refs.dat file 28- 32 F5.2 mag DVMAG Difference between stellar absolute magnitude and that for an MS star of the same B-V color
Note (1): from Valenti et al. (2005, Cat. J/ApJS/159/141>), uncertainties <20%.
Byte-by-byte Description of file: table12.dat
Bytes Format Units Label Explanations
1- 10 A10 --- StarA Name of primary 14- 23 A10 --- StarB Name of secondary 27- 30 F4.2 [yr] logtA Activity-gyro age for component A 32- 36 F5.2 [yr] logtB Activity-gyro age for component B 38- 41 F4.2 [yr] logt Mean gyro age for the system 43- 46 F4.2 [yr] e_logt rms uncertainty on logt 47 A1 --- n_StarA [a] Note for HD 137763 (1)
Note (1): a: HD 137763 is a pathological case discussed in footnote 10.
Byte-by-byte Description of file: table13.dat
Bytes Format Units Label Explanations
1- 6 I6 --- HD HD number (Cat. III/135) 8- 13 I6 --- HIP HIP number (Cat. I/311) 15- 21 A7 --- GJ Nearby Star Catalog designation (Cat. V/70) 23- 33 A11 --- OName Other name 35- 40 F6.2 mas plx Parallax 42- 45 F4.2 mas e_plx rms uncertainty on plx 47- 51 F5.3 mag B-V B-V colour index 53 I1 --- r_B-V Reference for B-V, in refs.dat file 55- 60 F6.3 --- logR'HK R'HK index 62- 63 I2 --- r_logR'HK Reference for logR'HK, in refs.dat file 65- 69 F5.2 mag Vmag V magnitude 71- 74 F4.2 mag VMAG Absolute V magnitude 76- 80 F5.2 mag DVMAG Difference between stellar absolute magnitude and that for an MS star of the same B-V color 82- 96 A15 --- SpType MK spectral type 98- 99 I2 --- r_SpType Reference for SpType, in refs.dat file 101 A1 --- l_tau1 Limit flag on tau1 102-104 F3.1 Gyr tau1 Age from using the revised activity-age relation 106 A1 --- l_tau2 Limit flag on tau2 107-110 F4.1 Gyr tau2 Age inferred from converting the chromospheric activity levels to a rotation period via the Rossby number and then converting the rotation period to an age using the revised gyro relation
Byte-by-byte Description of file: refs.dat
Bytes Format Units Label Explanations
1- 2 I2 --- Ref Reference code 4- 22 A19 --- BibCode BibCode 24- 44 A21 --- Aut Author's name 47-185 A139 --- Com Comments
History: From electronic version of the journal
(End) Patricia Vannier [CDS] 04-May-2010
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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