J/A+A/441/631 Δa photometry of CP stars (Paunzen+, 2005)
On the detection of chemically peculiar stars using Δa photometry.
Paunzen E., Stuetz C., Maitzen H.M.
<Astron. Astrophys., 441, 631-640 (2005)>
=2005A&A...441..631P 2005A&A...441..631P
ADC_Keywords: Stars, peculiar ; Photometry, uvby
Keywords: stars: chemically peculiar - stars: early-type -
techniques: photometric
Abstract:
We have summarized all Δa measurements for galactic field stars
(1474 objects) from the literature published over more than two
decades. These measurements were, for the first time, compiled and
homogeneously analyzed. The Δa intermediate band photometric
system samples the depth of the 5200Å flux depression by comparing
the flux at the center with the adjacent regions with bandwidths of
110Å to 230Å. Because it was slightly modified over the last
three decades, we checked for systematic trends for the different
measurements but found no correlations whatsoever. The Δa
photometric system is most suitable to detecting magnetic chemically
peculiar (CP) stars with high efficiency, but is also capable of
detecting a small percentage of non-magnetic CP objects. Furthermore,
the groups of (metal-weak) lambda Bootis, as well as classical
Be/shell stars, can be successfully investigated. In addition, we also
analyzed the behaviour of supergiants (luminosity class I and II). On
the basis of apparent normal type objects, the correlation of the
3sigma significance limit and the percentage of positive detection for
all groups was derived.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table4.dat 29 300 Confirmed chemically peculiar stars from Renson
(1991, Cat. III/162), the type of peculiarity
was taken from the literature
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See also:
http://obswww.unige.ch/gcpd/ph75.html : Maitzen photometric system
III/162 : General Catalogue of Ap and Am stars (Renson+ 1991)
Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- Ren Renson (III/162) number of the star
7- 12 I6 --- HD ?=- HD (III/135) number of the star
14- 16 I3 mmag (b-y)0 Dereddened b-y colour index
18- 19 I2 mmag Da Δa index in Maitzen photometric system
22- 29 A8 --- Spec Spectral type of CP star
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 28-Jul-2006