J/A+A/389/149 EROS II periodic stars towards Galactic spiral arm (Derue+, 2002)
Observations of periodic variable stars towards the Galactic spiral arms by
EROS II.
Derue F., Marquette J-B., Lupone S., Afonso C., Alard C., Albert J-N.,
Amadon A., Andersen J., Ansari R., Aubourg E., Bareyre P., Bauer F.,
Beaulieu J-P., Blanc G., Bouquet A., Char S., Charlot X., Couchot F.,
Coutures C., Ferlet R., Fouque P., Glicenstein J-F., Goldman B.,
Gould A., Graff D., Gros M., Haissinski J., Hamilton J-C., Hardin D.,
de Kat J., Kim A., Lasserre T., Le Guillou L., Lesquoy E., Loup C.,
Magneville C., Mansoux B., Maurice E., Milsztajn A., Moniez M.,
Palanque-Delabrouille N., Perdereau O., Prevot L., Regnault N., Rich J.,
Spiro M., Vidal-Madjar A., Vigroux L., Zylberajch S.
The EROS collaboration
<Astron. Astrophys. 389, 149 (2002)>
=2002A&A...389..149D 2002A&A...389..149D
ADC_Keywords: Stars, variable ; Photometry
Keywords: techniques: photometry - stars: variables: general -
galaxy: stellar content
Abstract:
We present the results of a search for variable stars in a photometric
survey of a six square degree region along the Galactic plane at
(l=305°, b=-0.8°) and (l=330°, b=-2.5°). This survey
was performed in the framework of the EROS II (Experience de
Recherche d'Objets Sombres) microlensing program. The variable stars
were found among 1913576 stars that were monitored between April and
June 1998 in two passbands, with an average of 60 measurements. For
the periodicity search, a new method is proposed well suited when the
photometric data are unevenly distributed in time, as is our case.
1362 objects whose luminosity varies were selected. Among them we
identified 9 Cepheids, 19 RR Lyrae, 34 Miras, 176 eclipsing binaries
and 266 Semi-Regular stars. Most of them are newly identified objects.
The cross-identification with known catalogues has been performed.
Our catalogue and light curves are available from our Web site
(http://www.lal.in2p3.fr/recherche/eros/GSA/EROS2-GSA-periodic.html)
Description:
The EROS II catalog of variable stars in the disc (EROS2-GSA) is based
on observations made on EROS II images and contains about 1362 stars.
The positional data, magnitudes in EROS passbands, period of variation
and Fourier coefficients (for pulsating stars) and their cross
identification with Simbad objects are presented.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
shortper.dat 150 431 Periods lower than 30 days (table 3)
longper.dat 151 930 Periods greater than 30 days (table 4)
lightcur.dat 52 749 Light curves file names
lcurve/* . 1497 Red and visible light curves
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See also:
http://eros.in2p3.fr : EROS Experiment Home Page
http://www.lal.in2p3.fr/recherche/eros/GSA :
EROS II Galactic Spiral Arms project Home page
Byte-by-byte Description of file: shortper.dat
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Bytes Format Units Label Explanations
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1- 14 A14 --- EROS2-GSA Designation (G1)
16- 27 A12 --- Int Internal number (G2)
30- 31 I2 h RAh Right Ascension J2000 (hours)
33- 34 I2 min RAm Right Ascension J2000 (minutes)
36- 40 F5.2 s RAs Right Ascension J2000 (seconds)
42 A1 --- DE- Declination J2000 (sign)
43- 44 I2 deg DEd Declination J2000 (degrees)
46- 47 I2 arcmin DEm Declination J2000 (minutes)
49- 53 F5.2 arcsec DEs Declination J2000 (seconds)
55- 59 F5.2 mag Reros Instrumental mean EROS magnitude
61- 64 F4.2 mag A(Reros) Amplitude of the R light curve
66- 70 F5.2 mag Veros Instrumental mean EROS magnitude
72- 75 F4.2 mag A(Veros) Amplitude of the V light curve
77- 83 F7.4 d Per Period from a Fourier fit
85- 89 F5.3 ---- R21 ? R21 Fourier coefficient (for pulsatings)
91- 95 F5.3 ---- e_R21 ? Error on R21 (for pulsatings)
97-101 F5.3 ---- R31 ? R31 Fourier coefficient (for pulsatings)
103-107 F5.3 ---- e_R31 ? Error on R31 (for pulsatings)
109-114 F6.3 ---- F21 ? F21 Fourier coefficient (for pulsatings)
115-120 F6.3 ---- e_F21 ? Error on F21 (for pulsatings)
123-126 A4 ---- Type Type of variability (G3)
128-150 A23 ---- CrossId Cross Identification with Simbad Objects
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Byte-by-byte Description of file: longper.dat
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Bytes Format Units Label Explanations
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1- 14 A14 --- EROS2-GSA Designation (G1)
16- 27 A12 --- Int Internal number (G2)
30- 31 I2 h RAh Right Ascension J2000 (hours)
33- 34 I2 min RAm Right Ascension J2000 (minutes)
36- 40 F5.2 s RAs Right Ascension J2000 (seconds)
42 A1 --- DE- Declination J2000 (sign)
43- 44 I2 deg DEd Declination J2000 (degrees)
46- 47 I2 arcmin DEm Declination J2000 (minutes)
49- 53 F5.2 arcsec DEs Declination J2000 (seconds)
55- 59 F5.2 mag Reros Instrumental mean EROS magnitude
61- 64 F4.2 mag A(Reros) Amplitude of the R light curve
66- 70 F5.2 mag Veros Instrumental mean EROS magnitude
72- 75 F4.2 mag A(Veros) Amplitude of the V light curve
77- 81 F5.2 d Per Period from a Fourier fit
83- 86 A4 ---- Type Type of variability (G3)
88-151 A64 ---- CrossId Cross Identification with Simbad Objects
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Byte-by-byte Description of file: lightcur.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- Int Internal number (G2)
14- 30 A17 --- lcred File name of the red light curve in
lcurve sub-directory (*r.dat)
33- 49 A17 --- lcvis File name of the visible light curve in
lcurve sub-directory (*v.dat)
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Byte-by-byte Description of file: lcurve/*
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Bytes Format Units Label Explanations
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2- 11 F10.6 d Time Time of exposure in HJD-2447892.5
14- 19 F6.3 mag mag EROS R or V magnitude
21- 25 F5.3 mag e_mag Error on EROS R or V magnitude
28- 30 I3 --- Nmes Index of measurement
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Global notes:
Note (G1): The identifier of each star is given according to the
recommendations of the IAU Commission 5 in The Rules and Regulations
for Nomenclature (see the Annual Index of A&A).
The general acronym used in the catalogue is EROS2 GSA followed by
J2000 equatorial coordinates in the format JHHMMSS±DDMMSS.
Note (G2): The identifier Int gives some information relating to the
internal organisation of the EROS database:
gnnnn or tmnnn is the name of the field, followed by the CCD number
and the location on the image following the nomenclature indicated in
the paper.
The remaining number is the star identifier used in the EROS database.
As an example, J133312-634718(tm5515n5785) is the name of the 5785th
star observed in quarter n of CCD 5 in the field tm551. The J2000
equatorial coordinates of this star are 13:33:12.31, -63:47:18.4.
Note (G3): Variability type:
C = classical Cepheids
S = s-Cepheids
puls = miscellaneous pulsating stars
EA,EB,EW = eclipsing binaries
misc = miscellaneous
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Acknowledgements: Frederic Derue
History:
* 20-Aug-2002: lightcurve files adapted (restriction to 3 decimals for
the magnitudes)
(End) Frederic DERUE [LAL-Orsay], Patricia Bauer [CDS] 16-Apr-2002