J/A+A/528/A148 uvbyβ photometry of early type stars (Handler, 2011)
uvbyβ photometry of early type open cluster and field stars.
Handler G.
<Astron. Astrophys. 528, A148 (2011)>
=2011A&A...528A.148H 2011A&A...528A.148H
ADC_Keywords: Clusters, open ; Stars, early-type ; Photometry, uvby, beta
Keywords: stars: early-type - stars: fundamental parameters -
open clusters and associations: general - techniques: photometric -
stars: oscillations - asteroseismology
Abstract:
The β Cephei stars and slowly pulsating B (SPB) stars are massive
main sequence variables. The strength of their pulsational driving
strongly depends on the opacity of iron-group elements. As many of
those stars naturally occur in young open clusters, whose
metallicities can be determined in several fundamental ways, it is
logical to study the incidence of pulsation in several young open
clusters. To provide the foundation for such an investigation,
Stroemgren-Crawford uvbyβ photometry of open cluster target stars
was carried out to determine effective temperatures, luminosities, and
therefore cluster memberships. In the course of three observing runs,
uvbyβ photometry for 168 target stars was acquired and transformed
into the standard system by measurements of 117 standard stars. The
list of target stars also included some known cluster and field β
Cephei stars, as well as β Cephei and SPB candidates that are
targets of the asteroseismic part of the Kepler satellite mission. The
uvbyβ photometric results are presented. The data are shown to be
on the standard system, and the properties of the target stars are
discussed: 140 of these are indeed OB stars, a total of 101 targets
lie within the β Cephei and/or SPB star instability strips, and
each investigated cluster contains such potential pulsators. These
measurements will be taken advantage of in a number of subsequent
publications.
Description:
The reduced uvbyβ photometry for all observed stars is presented.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 62 117 uvbyβ photometry of standard stars
table4.dat 62 107 uvbyβ photometry of open cluster target stars
table5.dat 62 19 uvbyβ photometry of known β Cephei and
other target stars
table6.dat 62 42 uvbyβ photometry of early-type stars
in the Kepler field
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Byte-by-byte Description of file: table3.dat table4.dat table5.dat table6.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- Star Star identification (1)
17 I1 --- N Number of uvby measurements
20- 25 F6.3 mag Vmag ?=- V magnitude
26 A1 --- n_Vmag [*] * for measurement not used (2)
28- 33 F6.3 mag b-y ?=- b-y colour index
34 A1 --- u_b-y [:] : for measurement outside validity (3)
35 A1 --- n_b-y [*] * for measurement not used (2)
37- 42 F6.3 mag m1 ?=- m1 index
43 A1 --- u_m1 [:] : for measurement outside validity (3)
44 A1 --- n_m1 [*] * for measurement not used (2)
45- 50 F6.3 mag c1 ?=- c1 index
51 A1 --- u_c1 [:] : for measurement outside validity (3)
52 A1 --- n_c1 [*] * for measurement not used (2)
54- 58 F5.3 mag beta ?=- Hβ value
59 A1 --- u_beta [:] : for measurement outside validity (3)
60 A1 --- n_beta [*] * for measurement not used (2)
62 I1 --- o_beta Number of Hβ measurements
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Note (1): Open cluster stars are identified with their WEBDA designation.
Note (2): Measurements not used for computing transformation equations are
marked with an asterisk
Note (3): Measurements outside the validity of the transformation equations
are marked with a colon
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Acknowledgements:
Gerald Handler, gerald.handler(at)univie.ac.at
(End) Patricia Vannier [CDS] 28-Feb-2011