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Detailed Description of II/233
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II/233 Tycho variables stars (Piquard 2001)
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Detection and classification of Tycho variables stars
Piquard S.
<PhD Dissertation, Strasbourg, (2001)>
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ADC_Keywords: Stars, variable ; Magnitudes
Description:
We present the results of the classification procedure described in
Piquard's PhD thesis applied to the 1091 stars presented in Piquard et
al. (2001. Cat. J/A+A/373/576). In those six tables we give
indication of variability type for all the stars detected as variables
in Piquard et al. (2001, Cat. J/A+A/373/576). First of all, we
looked for periodic signals in the light curves using adapted Renson's
(Renson, 1978A&A....63..125R) and Stellingwerf's (Stellingwerf,
1978ApJ...224..953S) methods applied to the tree different photometric
bands from Tycho (Cat. I/239): T, BT, VT (the T band is defined
from the added count-rates in the BT and VT channels, Grossmann et
al.. 1995A&A...304..110G). Then we developed a semi-automatic method
using 5 parameters (Period, color index, reduced proper motion from
Tycho-2 catalogue (Cat. I/259), 2 indicators of the shape of the
light curve) and a maximum likelihood method, combined with a careful
look on the light curves. Finaly, the identification of the
variability type is kept only if the resulting light curve is
convincing (periodic the star has the P status, if not periodic the
star has the U status); else we need more information about the star
and is has the A status. All this identifications are indications
since the quality of the light curves are often poor, particularly
when the star is fainter than T=10.
File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file
tablet.dat 174 954 Stars detected as variable in T
tableb-v.dat 174 107 Stars detected as variable in BT-VT
thesis.ps 132 391718 PostScript version of the thesis
See also:
I/239 : The Hipparcos and Tycho Catalogues (ESA 1997)
I/259 : The Tycho-2 Catalogue (Hog+ 2000)
II/214 : Combined General Catalogue of Variable Stars (Kholopov+ 1998)
J/A+A/373/576 : Detection of Tycho variables stars (Piquard+, 2001)
Byte-by-byte Description of file: tablet.dat tableb-v.dat
Bytes Format Units Label Explanations
1 A1 --- Status [PUA] Status of the star (1)
4- 15 A12 --- TYC Tycho designation (Cat. I/239)
17- 28 F12.8 deg RAdeg Tycho right ascension (ICRS, Epoch 1991.25)
30- 41 F12.8 deg DEdeg Tycho declination (ICRS, Epoch 1991.25)
43- 48 I6 --- HIP ?=0 Hipparcos (Cat. I/239) number
50- 55 A6 --- VarType Hipparcos variability type
(P5 field of HIP) (2)
58- 60 I3 --- Nt Number of used detected transits
62- 67 F6.3 mag BTmag Tycho BT magnitude from Tycho-2
(Hoeg et al., 2000, Cat. I/259)
69- 74 F6.3 mag VTmag Tycho VT magnitude from Tycho-2
(Hoeg et al., 2000, Cat. I/259)
77- 85 F9.7 --- tT [0,1] Probability of a constant star to appear
variable in T magnitude (3)
88- 96 F9.7 --- t(BT-VT) [0,1] Probability of a constant star to appear
variable in (BT-VT) (3)
98 I1 --- VarFlag [1,3]? Amplitude flag (H6 field of HIP) (4)
100 A1 --- HvarType [CDMPRU] Period or Unsolved in Hipparcos
(H52 field in HIP) (5)
102 A1 --- GN [GN] Cross identification with GCVS or NSV
104 A1 --- VarType2 [UVW] Variability flag from Tycho
(T48 field) (6)
106 A1 --- Dup [RYZ] Duplicity detection from Tycho
(T49 field) (7)
108 A1 --- An [AB] Flag marking either Annex A or Annex B of
the Tycho Epoch Photometry Annexes (field T50)
112-120 A9 --- Name GCVS name of the star if existing
122-126 F5.3 d PerOld Known period
128-135 A8 --- SpType Spectral type from Simbad
137-147 F11.6 d Period Best period found
150-154 F5.3 d Ampl Amplitude of the light curve after best fit
157-161 F5.3 --- Dur Duration of the light curve after best fit
(in phase unit)
163 A1 --- --- [APU] Status (repeated) (1)
165-172 A8 --- Type This work type of variability
(ech: inadequate time sampling suspected)
174 A1 --- New [*] *: New variable
Note (1): Status of the stars:
P: Stars found to be periodic
U: Stars with no period found
A: Stars needing more observations
Note (2): This is the 6-letter type defined in the General Catalog of Variable
Stars (Cat. II/214). See also the "Types of Variability" section
below reproduced from the Hipparcos catalogue.
Note (3): The values are calculated even for stars having less than 10
observations. The calculation of the probability is then uncertain.
Note (4): The values are
1: < 0.06mag ; 2: 0.06-0.6mag ; 3: >0.6mag
Note (5): Hipparcos-defined type of variability (a blank entry signifies that
the entry could not be classified as variable or constant):
C : no variability detected ("constant")
D : duplicity-induced variability
M : possibly micro-variable (amplitude < 0.03mag)
P : periodic variable
R : V-I colour index was revised due to variability analysis
U : unsolved variable which does not fall in the other categories
Note (6): Tycho variability flag:
U : apparent variability in the Tycho data; may be due to duplicity
V : strong evidence of intrinsic variability
W : suspected intrinsic variability
Note (7): Tycho duplicity flag:
D: duplicity clearly indicated (BTmag and VTmag refer to combined light)
R: duplicity weakly indicated, combined with indication of variability
S: duplicity suspected
Y: investigation for duplicity carried out on Tycho data, no indication
of duplicity was found
Z: investigation for duplicity not carried out
blank: Hipparcos star not observed by Tycho
Types of Variability: (copied from Hipparcos I/239 ReadMe):
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Code Description Class of Variable
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ACV {alpha}2 Canum Venaticorum type (including ACVO) rotating
ACYG {alpha} Cygni type pulsating
BCEP {beta} Cephei type (including BCEPS) pulsating
BY BY Draconis type rotating
CEP Cepheids (including CEP(B)) pulsating
CST constant stars (considered as variable by
some observer(s)) -
CW W Virginis type pulsating
CWA W Virginis type (periods > 8 days) pulsating
CWB W Virginis type (periods < 8 days) pulsating
DCEP {delta} Cephei type (including DCEPS) pulsating
DSCT {delta} Scuti type (including DSCTC) pulsating
E (E+, E/..) eclipsing binary
EA Algol type (EA+, EA/..) eclipsing binary
EB {beta} Lyrae type (EB/..) eclipsing binary
ELL rotating ellipsoidal (ELL+.. or/..) rotating
EW W Ursae Majoris type (EW/i..) eclipsing binary
FKCOM FK Comae Berenices type rotating
GCAS {gamma} Cassiopeiae type eruptive
I irregular (I, IA, IB, In, InT, Is) eruptive
IN irregular (INA, INAT, INB, INSA, INSB, INST, INT) eruptive
IS irregular (ISA, ISB) eruptive
L slow irregular (L, LB, LC) pulsating
M Mira Ceti type pulsating
N slow novae (NB, NC) cataclysmic
NA fast novae cataclysmic
NL nova-like cataclysmic
NR recurrent novae cataclysmic
PVTEL PV Telescopii type pulsating
RCB R Coronae Borealis type eruptive
RR RR Lyrae type (RR, RRAB, RRB, RRC) pulsating
RS RS Canum Venaticorum type eruptive
RV RV Tauri type (RV, RVA, RVB) pulsating
SARV small-amplitude red variables pulsating/rotating
SDOR S Doradus type eruptive
SPB slowly pulsating B stars pulsating
SR semi-regular (SR, SRA, SRB, SRC, SRD) pulsating
SXARI SX Arietis type rotating
SXPHE SX Phoenicis type pulsating
UV UV Ceti type eruptive
WR Wolf-Rayet eruptive
XNG X-ray nova-like system X-ray binary
XP X-ray pulsar X-ray binary
ZAND Z Andromedae type cataclysmic
Acknowledgements: Sandrine Piquard
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(End) Patricia Bauer [CDS] 09-Nov-2001
| The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line |
