J/A+A/476/307 Period variations in galactic RRab stars (Le Borgne+, 2007)
Stellar evolution through the ages: period variations in galactic RRab stars
as derived from the GEOS database and TAROT telescopes.
Le Borgne J.F., Paschke A., Vandenbroere J., Poretti E., Klotz A.,
Boeer M., Damerdji Y., Martignoni M., Acerbi F.
<Astron. Astrophys., 476, 307-316 (2007)>
=2007A&A...476..307L 2007A&A...476..307L
ADC_Keywords: Stars, variable
Keywords: astronomical data bases: miscellaneous - stars: evolution -
stars: horizontal-branch - stars: variables: RR Lyr
Abstract:
The theory of stellar evolution can be more closely tested if we have
the opportunity to measure new quantities. Nowadays, observations of
galactic RR Lyr stars are available on a time baseline exceeding 100
years. Therefore, we can exploit the possibility of investigating
period changes, continuing the pioneering work started by V.P.
Tsesevich in 1969. We collected the available times of maximum
brightness of the galactic RR Lyr stars in the GEOS RR Lyr database
(http://dbrr.ast.obs-mip.fr/). Moreover, we also started new
observational projects, including surveys with automated telescopes,
to characterise the O-C diagrams better. The database we built has
proved to be a very powerful tool for tracing the period variations
through the ages. We analyzed 123 stars showing a clear O-C pattern
(constant, parabolic or erratic) by means of different least-squares
methods.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 77 54 Refined linear elements for stars showing a
constant period
table4.dat 128 27 Parabolic elements for RRab stars showing a
well-defined linearly increasing period
table5.dat 128 21 Parabolic elements for RRab stars showing a
well-defined linearly decreasing period
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See also:
II/250 : Combined General Catalogue of Variable Stars (Samus+ 2004)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Star Star name
11- 13 I3 --- Nm Number of maxima observed
15- 17 I3 yr Obs Number of years for the covered period
19- 22 I4 yr Date1 Time coverage
23 A1 --- --- [-]
24- 27 I4 yr Date2 Time coverage
29- 40 F12.4 d T0 Epoch in Heliocentric Julian date
42- 47 F6.4 d e_T0 rms uncertainty on Epoch
49- 58 F10.8 d Per Period
60- 69 F10.8 d e_Per rms uncertainty on Per
71- 76 F6.4 d sd Standard deviation for Epoch
77 A1 --- n_sd [B] B for stars having a known Blazhko effect
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Byte-by-byte Description of file: table[45].dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Star Star name
11- 13 I3 --- Nm Number of maxima observed
15- 17 I3 yr Obs Number of years for the covered period
19- 22 I4 yr Date1 Time coverage
23 A1 --- --- [-]
24- 27 I4 yr Date2 Time coverage
29- 40 F12.4 d T0 Epoch in Heliocentric Julian date
42- 47 F6.4 d e_T0 rms uncertainty on Epoch
49- 58 F10.8 d Per Period
60- 69 F10.8 d e_Per rms uncertainty on Per
71- 76 F6.3 10-10d a3 Quadratic term (1)
78- 82 F5.3 10-10d e_a3 rms uncertainty on a3
84- 89 F6.4 d sd Standard deviation for Epoch
90 A1 --- n_sd [B] B for stars having a known Blazhko effect
92- 97 F6.2 10-10 dP/dt Period derivative
99-102 F4.2 10-10 e_dP/dt rms uncertainty on dP/dt
104-109 F6.3 d/Myr beta β parameter (β=0.0732x1010a3/<Per>)
111-115 F5.3 d/Myr e_beta rms uncertainty on beta
117-122 F6.3 --- alpha α parameter (α=β/<Per>)
124-128 F5.3 --- e_alpha rms uncertainty on alpha
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Note (1): The times of maximum have been fitted with the elements
C=T0+P0*E+a3*E2, where P0 is the period (in days) at epoch T0
and E is the cycle counter.
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 25-Jan-2008