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J/other/Obs/136.168       Early observations of M13 variables   (Osborn,+, 2016)

Early 20th-Century visual observations of M13 variable stars. Osborn W., Barnard E.E. <The Observatory 136, 168 (2016)> =2016Obs...136..168O (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, globular ; Stars, variable Keywords: clusters: globular: individual (M13) - stars: variable: clusters Description: In 1900 E.E. Barnard published 37 visual observations of Variable 2 (V2) in the globular cluster M13 made in 1899 and 1900. A review of Barnard's notebooks revealed he made many additional brightness estimates up to 1911, and he had also recorded the variations of V1 starting in 1904. These data provide the earliest-epoch light curves for these stars and thus are useful for studying their period changes. This paper presents Barnard's observations of the M13 variables along with their derived heliocentric Julian dates and approximate V magnitudes. These include 231 unpublished observations of V2 and 94 of V1. How these data will be of value for determining period changes by these stars is described. Objects: -------------------------------------------------------------------------- RA (2000) DE Designation(s) -------------------------------------------------------------------------- 16 41 46.51 +36 27 27.9 V1 = Cl* NGC 6205 SAW V1 = Cl* NGC 6205 BARN 202 16 41 35.90 +36 27 48.6 V2 = Cl* NGC 6205 SAW V2 = Cl* NGC 6205 BARN 59 -------------------------------------------------------------------------- File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 49 37 Barnard's published observations of Variable 2 table2.dat 78 75 Barnard's unpublished observations of Var. 2 table3.dat 65 56 Additional unpublished observations of Var. 2 table4.dat 51 111 Later observations of Var. 2 and Var. 1 table5.dat 70 9 Approximate V magnitudes from plates
See also: IV/26 : Hercules Messier 13 (M13) photometry (Ludendorff, 1905) J/A+A/398/541 : VI light-curves of the variable stars in M13 (Kopacki+, 2003) Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 12 A12 --- Date Local date of observation 15- 19 A5 "h:m" Time Local time of observation (hh:mm) 24- 26 F3.1 mag dmag ? Variable to comparison star magnitude difference 27- 29 A3 --- n_dmag [Max ] Note on dmag 31- 41 F11.3 d HJD Derived heliocentric Julian Date 46- 49 F4.1 mag Vmag Derived approximate V magnitude
Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 12 A12 --- Date Local date of observation 15- 19 A5 "h:m" Time Local time of observation (hh:mm) 23- 26 F4.2 mag dmag ? Variable to comparison star magnitude difference 27 A1 --- u_dmag [?] Uncertainty flag on dmag 29- 59 A31 --- n_dmag Note on dmag 61- 71 F11.3 d HJD Derived heliocentric Julian Date 75- 78 F4.1 mag Vmag Derived approximate V magnitude of Variable 2
Byte-by-byte Description of file: table3.dat
Bytes Format Units Label Explanations
1- 12 A12 --- Date Local date of observation 15- 19 A5 "h:m" Time Local time of observation (hh:mm) 23- 26 F4.2 mag dmag ? Variable to comparison star magnitude difference 27 A1 --- u_dmag [?] Uncertainty flag on dmag 28- 34 A7 --- n_dmag Note on dmag 36- 46 F11.3 d HJD Derived heliocentric Julian Date 49- 52 F4.1 mag Vmag Derived approximate V magnitude of Variable 2 55- 65 A11 --- Notes Notes
Byte-by-byte Description of file: table4.dat
Bytes Format Units Label Explanations
1- 12 A12 --- Date Local date of observation 16- 26 F11.3 d HJD ? Derived heliocentric Julian Date 30- 33 F4.1 mag V2 ? Derived approximate V magnitude of V2 37- 40 F4.1 mag V1-841 ? Derived V magnitude of Var 1 (L841 comparison) 44- 47 F4.1 mag V1-np ? Derived V magnitude of Var 1 (np comparison) 51 I1 --- Notes [1/2]? How sidereal time used in computing HJD (1)
Note (1): How sidereal time used in computing HJD flag as follows: 1 = Barnard gave both local time and sideral time. Both used in deriving HJD. 2 = Barnard gave only sideral time.
Byte-by-byte Description of file: table5.dat
Bytes Format Units Label Explanations
1- 6 A6 --- Plate Yerkes 40-inch refractor plate number 9- 19 A11 --- Date Local date of observation 22- 40 A19 --- Time Listed exposure time of plate (hh:mm) 44- 54 F11.3 d HJD Derived heliocentric Julian Date 58- 62 F5.2 mag V2mag Derived approximate V magnitude of Variable 2 66- 70 F5.2 --- V1mag Derived approximate V magnitude of Variable 1
Acknowledgements: prepared by Wayne H. Osborn [Yerkes Observatory] in 2018 References: Barnard, 1900ApJ....12..182B Discovery and period of a small variable star in the cluster M13 Hercules
(End) Patricia Vannier [CDS] 03-May-2018
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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