J/ApJ/559/1060 Variables in 47 Tuc (Albrow+, 2001)
The frequency of binary stars in the core of 47 Tucanae.
Albrow M.D., Gilliland R.L., Brown T.M., Edmonds P.D., Guhathakurta P.,
Sarajedini A.
<Astrophys. J. 559, 1060 (2001)>
=2001ApJ...559.1060A 2001ApJ...559.1060A
ADC_Keywords: Clusters, globular ; Stars, variable ; Binaries, eclipsing ;
Photometry
Keywords: binaries: eclipsing - binaries: general -
globular clusters: individual (NGC 104, 47 Tucanae)
Abstract:
Differential time series photometry has been derived for 46,422
main-sequence stars in the core of 47 Tucanae. The observations
consisted of near-continuous 160 s exposures alternating between the
F555W and F814W filters for 8.3 days in 1999 July with the Wide Field
Planetary Camera 2 on the Hubble Space Telescope. Using Fourier and
other search methods, 11 detached eclipsing binaries and 15 W Ursa
Majoris stars have been discovered plus an additional 10 contact or
near-contact noneclipsing systems. After correction for nonuniform
area coverage of the survey, the observed frequencies of detached
eclipsing binaries and W UMa stars within 90" of the cluster center
are 0.022% and 0.031%, respectively.
The data were taken over an 8.3 day period, 1999 July 3-11, during
which HST was pointed continuously at 47 Tuc.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
tables.dat 95 141 HST photometry of 47 Tuc variables
(tables 1-8 of the publication)
--------------------------------------------------------------------------------
See also:
J/other/Sci/292.2290 : Chandra compact binaries in 47 Tuc (Grindlay+, 2001)
J/ApJS/85/293 : HST Observations of core of 47 Tuc (de Marchi+ 1993)
J/A+A/315/40 : Photometry of the Tuc dwarf galaxy (Saviane, 1996)
J/A+AS/128/19 : Variable stars in 47 Tuc fields 104A-E (Kaluzny+ 1998)
Byte-by-byte Description of file: tables.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1 I1 --- TNO Type of variable (1)
3- 9 A7 --- VName Star variable name (2)
11 A1 --- l_Per Limit flag on Per
12- 18 F7.4 d Per ? Period
20- 25 F6.3 d Epoch ? Epoch of the primary minimum, HJD-2451300
(only for eclipsing binaries)
27- 31 F5.3 mag AV ? V-band semi-amplitude (only for BY Draconis
and red straggler variables)
33- 38 F6.3 mag Vmag V magnitude
40- 45 F6.3 mag U-V ? U-V colour index
47- 52 F6.3 mag V-I ? V-I colour index
54- 55 I2 h RAh Right ascension (J2000) (3)
57- 58 I2 min RAm Right ascension (J2000) (3)
60- 66 F7.4 s RAs Right ascension (J2000) (3)
70 A1 --- DE- Declination sign (J2000) (3)
71- 72 I2 deg DEd Declination (J2000) (3)
74- 75 I2 arcmin DEm Declination (J2000) (3)
77- 82 F6.3 arcsec DEs Declination (J2000) (3)
84- 95 A12 --- Class Classification
--------------------------------------------------------------------------------
Note (1): Type of variables as follows:
1 = Eclipsing Binaries
2 = W UMa Binaries
3 = Non-eclipsing Contact and Semi-detached Binaries
4 = BY Draconis Variables
5 = Red Straggler Variables
6 = Other Variables
7 = Variable Giants
8 = Variable RGB-AGB stars
Note (2): Star variable name as AAA-VNN, where
AAA is the HST chip (PC1, WF2, WF3 or WF4)
and VNN the variable number in the field.
Simbad nomenclature as follows:
PC1-VNN = Cl* NGC 104 EGG VNN
WFN-VNN = Cl* NGC 104 AGBWF N-NN
Note (3): Coordinates calculated using the STSDAS task METRIC and
archival image u5jm070cr.
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) James Marcout, Patricia Bauer [CDS] 24-Apr-2002