II/162 CCD search for Cepheids in Crux and Centaurus (Caldwell+, 1991)
A scanner CCD search for Cepheids and other variables in Crux and Centaurus.
Caldwell J.A.R., Keane M.J., Schechter P.L.
<Astron. J., 101, 1763 (1991)>
=1991AJ....101.1763C 1991AJ....101.1763C
ADC_Keywords: Stars, variable; Photometry
Abstract:
This catalog contains the results of a photometric survey for variable
stars in a 9.4 square degree region along the galactic plane in Crux
and Centaurus. A total of 300308 stars were observed at seven epochs
over 42 days; 224 524 of these stars were detected at multiple epochs
and were tested for possible variations in brightness that exceed
observational error. 2422 stars are identified as variable at a formal
confidence level of 99%; 270 of the new variables brighter than I=14.0
are classified as long period variables. A list of 242 likely short
period variables with RMS amplitudes ≥0.060mag is given. From this
list, 37 Cepheid candidates were selected after inspection of their
light curves.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
data1.dat 79 19124 The complete list of probable variables
data2.dat 79 225052 Observations with RA = 11:39:40 to 12:15:41 and
declination = -63:05:12 to -62:46:46 (1950)
data3.dat 79 207787 Observations with RA = 11:39:40 to 12:15:12 and
declination = -62:46:47 to -62:27:26 (1950)
data4.dat 79 254005 Observations with RA = 11:39:40 to 12:14:44 and
declination = -62:27:27 to -62:03:11 (1950)
data5.dat 79 175070 Observations with RA = 11:39:40 to 12:14:16 and
declination = -62:03:12 to -61:47:46 (1950)
data6.dat 79 187418 Observations with RA = 11:39:39 to 12:13:48 and
declination = -61:47:47 to -61:24:46 (1950)
data7.dat 79 224071 Observations with RA = 13:10:14 to 13:46:17 and
declination = -63:06:09 to -62:54:03 (1950)
data8.dat 79 182283 Observations with RA = 13:10:15 to 13:45:52 and
declination = -62:53:19 to -62:36:32 (1950)
data9.dat 79 80086 Observations with RA = 13:10:15 to 13:45:28 and
declination = -62:35:49 to -62:23:27 (1950)
table4.dat 69 242 High amplitude, short-period variables found
in this survey
table5.dat 61 270 Long-period variables found in this survey
table6.dat 64 127 Variable stars identified with IRAS 12 µm
sources
table7.dat 54 18 *The ABCS carbon stars detected as variables
in this survey
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Note on table7.dat: ABCS: Aaronsom M. et al., 1989ApJS...70..637A 1989ApJS...70..637A
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Byte-by-byte Description of file: data*.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- image Image number
5- 8 I4 --- no Observed object within the image
10- 11 I2 h RAh Right Ascension, hours (1950)
13- 14 I2 min RAm Right Ascension, minutes (1950)
16- 20 F5.2 s RAs Right Ascension, seconds (1950)
22 A1 --- DE- Declination sign
23- 24 I2 deg DEd Declination, degrees (1950)
26- 27 I2 arcmin DEm Declination, minutes (1950)
29- 32 F4.1 arcsec DEs Declination, seconds (1950)
34- 39 F6.3 mag Icmag Cousins I magnitude
41- 45 F5.3 mag e_Icmag *Formal uncertainty in I
47- 55 F9.4 d JD-2440000 Modified Julian Date
57- 62 F6.2 pix x *X position within the image
64- 70 F7.2 pix y *Y position within the image
72 I1 --- class *Object classification
74- 79 I6 --- ID *Unique identifier un source catalog
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Note on e_Icmag:
Stars with centroids within 12 pixels of the beginning of the image
(which, unfortunately, includes the first stars on the variable star
list) may have suffered from a software bug in the data acquisition
and may have errors bigger than the formal errors.
Note on x and y:
The pixels are not square. They are 0.45" in the x direction and
either 3.7" or 1.85" in the y direction. The latter are less frequent
and go somewhat fainter than the lower resolution observations.
Note on class:
1 = single star
2 = galaxy
3 = one component of a multiple star
4 = an object for which the classification is uncertain
5 = too few pixels to determine classification or for which a position
was derived beyond the boundaries of the image or fit subraster
6 = should not be in the catalog
7 = too faint to attempt classification
8 = could not be modeled (too bright or cosmic ray) and has been excised
Note on ID:
This is a sequence number assigned for internal use, the first digit
being assigned according to the datafile number.
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Byte-by-byte Description of file: table4.dat, table5.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Name Variable name
11 A1 --- m_Name Multiplicity index on Name
13- 14 I2 h RAh Right ascension 1950
16- 17 I2 min RAm Right ascension 1950
19- 23 F5.2 s RAs Right ascension 1950
25 A1 --- DE- Declination sign
26- 27 I2 deg DEd Declination 1950
29- 30 I2 arcmin DEm Declination 1950
32- 35 F4.1 arcsec DEs Declination 1950
37- 41 F5.2 mag Imag I (Cousins) magnitude
43- 47 F5.3 mag e_Imag ? rms uncertainty on Imag
49- 68 A20 --- Notes Notes (1)
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Note (1):
1. 1st rank Cepheid candidate.
2. 2nd rank Cepheid candidate.
3. Possible eclipse.
4. Possible LPV.
5. Additional photometry obtained 1990 Feb-Apr.
6. Variable is also identified as an IRAS 12µ source, see Table 6
7. Variable is also identified as a carbon star, see Table 7
Note: the remarks in table 5 are in bytes 49-61.
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Name Variable name
13- 14 I2 h RAh Right ascension 1950
16- 17 I2 min RAm Right ascension 1950
19- 23 F5.2 s RAs Right ascension 1950
25 A1 --- DE- Declination sign
26- 27 I2 deg DEd Declination 1950
29- 30 I2 arcmin DEm Declination 1950
32- 35 F4.1 arcsec DEs Declination 1950
37- 41 F5.2 mag Imag I (Cousins) magnitude
43- 52 A10 --- IRAS IRAS source name
54- 64 A11 --- Notes Notes (1)
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Note (1):
1. Variable was classified as LPV and is also listed in Table 5.
2. Variable was classified as short-period variable and is also
listed in Table 4. Likely a long period variable observed near
minimum or maximum light.
3. Object is also identified as a carbon star, see Table 7
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Byte-by-byte Description of file: table7.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- ABCS Aaronsom C stars (1)
7- 16 A10 --- Name Variable star name
18- 19 I2 h RAh Right ascension 1950
21- 22 I2 min RAm Right ascension 1950
24- 28 F5.2 s RAs Right ascension 1950
30 A1 --- DE- Declination sign
31- 32 I2 deg DEd Declination 1950
34- 35 I2 arcmin DEm Declination 1950
37- 40 F4.1 arcsec DEs Declination 1950
42- 54 A13 --- Notes Notes (2)
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Note (1): Aaronsom M. et al., 1989ApJS...70..637A 1989ApJS...70..637A
Note (2):
1. Classified as a LPV, see Table 5.
2. Also identified with an IRAS 12µ source, see Table 6.
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Historical note: The tables were keypunched at CDS; the data files were
provided by Dr. P. L. Schechter. The portion of this document which
refers to the tables and the Description were prepared by Simona Mei and
Patricia Bauer of the CDS in December 1994.
(End) Nancy Grace Roman [SSDOO/ADC] 30-Apr-1996