J/A+A/520/A46 Stroemgren photometry of 12 RR Lyrae stars (de Boer+, 2010)
Hysteresis of atmospheric parameters of 12 RR Lyrae stars based on multichannel
simultaneous Stroemgren photometry.
de Boer K.S., Maintz G.
<Astron. Astrophys. 520, A46 (2010)>
=2010A&A...520A..46D 2010A&A...520A..46D
ADC_Keywords: Stars, variable ; Photometry, uvby
Keywords: stars: variables: RR Lyrae - stars: horizontal-branch -
stars: oscillations - Galaxy: halo - techniques: photometric -
stars: fundamental parameters
Abstract:
RR Lyrae stars have been observed to improve the insight into
processes at work in their atmospheres.
Simultaneous Stroemgren-photometry allows to obtain a rapid sequence
of measurements in which photometric indices are unaffected by
non-optimum observing conditions. The indices y, b-y, and c1 are
used with an established calibration to derive Teff and to determine
the gravity, loggBJ from the Balmer jump, throughout the pulsation
cycle. By employing the equations for stellar structure, additional
parameters can be derived.
Description:
The data files contain y, b-y and then either v-b or u-v (see text of
paper). Some data lines have only y or have y and u-v; at those times
also measurements of Hbeta were made, that are not included because of
poor S/N (see text of paper). Note that (see text of paper) the u-v
values are derived from a time interpolation of v-b and u-b.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
stars.dat 55 12 Star positions
photom.dat 63 1471 Calibrated Stroemgren magnitudes and colour indices
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Byte-by-byte Description of file: stars.dat
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Bytes Format Units Label Explanations
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1- 6 A6 --- Name Simbad name
8- 9 I2 h RAh Simbad Hour of Right Ascension (J2000.0)
11- 12 I2 min RAm Simbad Minute of Right Ascension (J2000.0)
14- 17 F4.1 s RAs Simbad Second of Right Ascension (J2000.0)
19 A1 --- DE- Simbad Sign of the Declination (J2000.0)
20- 21 I2 deg DEd Simbad Degree of Declination (J2000.0)
23- 24 I2 arcmin DEm Simbad Arcminute of Declination (J2000.0)
26- 27 I2 arcsec DEs Simbad Arcsecond of Declination (J2000.0)
29- 38 F10.8 d Per Period
40- 44 F5.2 mag Bmag ? Simbad B band magnitude
46- 50 F5.2 mag Vmag ? Simbad V band magnitude
52- 55 A4 --- SpType Simbad MK spectral type
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Byte-by-byte Description of file: photom.dat
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Bytes Format Units Label Explanations
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1- 6 A6 ---- Name Name of the variable (GCVS)
10- 24 F15.7 d JD Time of observation (1)
28- 32 F5.2 mag ymag Stroemgren y magnitude
35- 40 F6.3 mag b-y ?=99.999 Stroemgren b-y colour index (2)
43- 48 F6.3 mag v-b ?=99.999 Stroemgren v-b colour index (2)
51- 56 F6.3 mag u-v ?=99.999 Stroemgren u-v colour index (2)
59- 63 F5.1 s ExpTime Shutter open time
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Note (1): given is the middle time of observation; start and end times can
be calculated with the shutter open time.
Note (2): A value of 99.999 means that no measurement of the colour index
was made at this time.
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Acknowledgements:
Klaas S. de Boer, deboer(at)astro.uni-bonn.de
(End) Patricia Vannier [CDS] 01-Oct-2010