J/AJ/124/1001 JHKs photometry of Cha I variables (Carpenter, 2002)
Near-infrared photometric variability of stars toward the
Chamaeleon I molecular cloud.
Carpenter J.M., Hillenbrand L.A., Skrutskie M.F., Meyer M.R.
<Astron. J. 124, 1001 (2002)>
=2002AJ....124.1001C 2002AJ....124.1001C
ADC_Keywords: Clusters, open ; Stars, variable ; Stars, pre-main sequence ;
Photometry, infrared
Keywords: infrared radiation - open clusters and associations: general -
stars: pre-main-sequence - stars: variables: general
Abstract:
We present the results of a J, H, and Ks photometric monitoring
campaign of a 0.72°x6° area centered on the Chamaeleon I
star-forming region. Data were obtained on 15 separate nights over a 4
month time interval, from January to May 2000, using the Two Micron
All Sky Survey south telescope. Out of a total of 34,539 sources
brighter than the photometric completeness limits (J=16.0, H=15.2, and
Ks=14.8), 95 exhibit near-infrared variability in one or more bands.
The variables can be grouped into a population of bright, red objects
that are associated with the Chamaeleon I association and a population
of faint, blue variables that are dispersed over the full 6° of
the survey and are likely field stars or older pre-main-sequence stars
unrelated to the present-day Chamaeleon I molecular cloud. Ten new
candidate members of Chamaeleon I, including eight brown dwarf
candidates, have been identified based on variability and/or
near-infrared-excess emission in the J-H versus H-Ks color-color
diagram. We also provide a compendium of astrometry and J, H, and Ks
photometry for previously identified members and candidate members of
Chamaeleon I.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 99 95 Near-infrared variable stars
table4.dat 82 10 New candidate members of Chamaeleon I
table5.dat 101 196 Near-infrared photometry for previously
identified Chamaeleon I members
table6.dat 185 196 Cross identification of Chamaeleon I members
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See also:
J/AJ/121/974 : JHK photometry in Cha I (Gomez+, 2001)
J/AJ/121/2673 : 3µm survey of the Chamaeleon I dark cloud (Kenyon+, 2001)
J/A+A/357/219 : ISOCAM observations in Cha I. (Persi+, 2000)
J/ApJ/445/280 : ROSAT survey of the Orion nebula region (Gagne+ 1995)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- CHSM Identification number
7- 22 A16 --- Name Previously identified variable star name
24- 33 F10.6 deg RAdeg Right Ascension in decimal degrees (J2000)
35- 44 F10.6 deg DEdeg Declination in decimal degrees (J2000)
46- 51 F6.3 mag Jmag ? The mean J-band magnitude
53- 58 F6.3 mag Hmag The mean H-band magnitude
60- 65 F6.3 mag Ksmag The mean Ks band magnitude
67- 71 F5.3 mag e_Jmag ? Observed photometric rms of Jmag
73- 77 F5.3 mag e_Hmag Observed photometric rms of Hmag
79- 83 F5.3 mag e_Ksmag Observed photometric rms of Ksmag
85- 86 I2 --- o_Jmag Number of quality photometric measurements
in Jmag
88- 89 I2 --- o_Hmag Number of quality photometric measurements
in Hmag
91- 92 I2 --- o_Ksmag Number of quality photometric measurements
in Ksmag
94- 98 F5.2 --- VI Stetson variability index
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- CHSM Sequential number
7- 16 F10.6 deg RAdeg Right ascension in decimal degrees (J2000.0)
18- 27 F10.6 deg DEdeg Declination in decimal degrees (J2000.0)
29- 34 F6.3 mag Jmag Mean J magnitude
36- 41 F6.3 mag Hmag Mean H magnitude
43- 48 F6.3 mag Ksmag Mean Ks magnitude
50- 54 F5.3 mag e_Jmag Observed rms uncertainty on Jmag
56- 60 F5.3 mag e_Hmag Observed rms uncertainty on Hmag
62- 66 F5.3 mag e_Ksmag Observed rms uncertainty on Ksmag
68- 70 A3 --- Var [Yes] Variable ?
72- 74 A3 --- Excess [Yes] JHKs excess ?
76- 82 A7 --- Name Other name
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- Name Commonly adopted name of the Chamaeleon I member
17- 18 I2 h RAh Hour of Right Ascension (J2000) (1)
20- 21 I2 min RAm Minute of Right Ascension (J2000) (1)
23- 27 F5.2 s RAs Second of Right Ascension (J2000) (1)
29 A1 --- DE- Sign of the Declination (J2000)(1)
30- 31 I2 deg DEd Degree of Declination (J2000) (1)
33- 34 I2 arcmin DEm Arcminute of Declination (J2000) (1)
36- 39 F4.1 arcsec DEs Arcsecond of Declination (J2000) (1)
41- 46 F6.3 mag Jmag ? The mean J-band magnitude (2)
48- 53 F6.3 mag Hmag ? The mean H-band magnitude (2)
55- 60 F6.3 mag Ksmag ? The mean Ks band magnitude (2)
62- 66 F5.3 mag e_Jmag ? Observed photometric rms of Jmag
68- 72 F5.3 mag e_Hmag ? Observed photometric rms of Hmag
74- 78 F5.3 mag e_Ksmag ? Observed photometric rms of Ksmag
80- 81 I2 --- o_Jmag ? Number of quality photometric measurements
in Jmag
83- 84 I2 --- o_Hmag ? Number of quality photometric measurements
in Hmag
86- 87 I2 --- o_Ksmag ? Number of quality photometric measurements
in Ksmag
89- 93 F5.2 --- VI ? Stetson variability index
95 A1 --- YSOP1 [0Y] Variable identified from this study or
General Catalogue of Variable Stars (3)
96 A1 --- YSOP2 [0Y] Contains Hα, Paβ, or
Brγ in emission (3)
97 A1 --- YSOP3 [0Y?] Contains lithium in absorption (3)
98 A1 --- YSOP4 [0Y] X-ray source (3)
99 A1 --- YSOP5 [0Y] Contains an infrared excess (3)
100 A1 --- YSOP6 [0Y] Far-infrared source (3)
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Note (1): See text for details on where the coordinates were obtained.
Note (2): For sources with J, H, and Ks photometry, o_Jmag, o_Hmag, and
o_Ksmag=1 in all three bands, but otherwise no tabulated Stetson
index, the photometry is from the Version 2 processing of the 2MASS
Working Database and the rms represents the photometric uncertainty
from the 2MASS processing pipeline.
Note (3): Flags:
Y = Indicates the characteristic has been identified with that star
in at least one study.
? = Indicates that the authors of the original paper expressed
uncertainty of the detection.
0 = Indicates the property has not yet been identified.
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 15 A15 --- Name Name (one of the following designation)
17- 21 I5 --- CHSM ? Identification number from this study
23- 30 A8 --- [CCE98] Cambresy et al., 1998A&A...338..977C 1998A&A...338..977C (1)
32- 38 A7 --- GCVS General Catalog of Variable Stars (II/214),
see Lopez & Girard, 1990PASP..102.1018L 1990PASP..102.1018L
40- 44 A5 --- W87 Whittet et al., 1991MNRAS.249..319W 1991MNRAS.249..319W
46- 51 A6 --- Sz Schwartz, 1977ApJS...35..161S 1977ApJS...35..161S (Sz NN)
53- 58 A6 --- S Hoffmeister, 1963VeSon...6....1H 1963VeSon...6....1H (SNNNN)
60- 66 A7 --- HM Henize & Mendoza, 1973ApJ...180..115H 1973ApJ...180..115H (HM NN) (2)
68- 76 A9 --- CHXR Feigelson et al., 1993ApJ...416..623F 1993ApJ...416..623F (CHXR NNA)
78- 84 A7 --- CHX Feigelson & Kriss, 1989ApJ...338..262F 1989ApJ...338..262F (CHX NNA)
86- 92 A7 --- Hn Hartigan, 1993AJ....105.1511H 1993AJ....105.1511H (Hn NNA)
93- 97 A5 --- HJM Hyland et al., 1982MNRAS.201.1095H 1982MNRAS.201.1095H and Jones et
al., 1985AJ.....90.1191J 1985AJ.....90.1191J (CN-NN, EN-NNA) (3)
99-105 A7 --- HBC Herbig Bell (1988, Cat. V/73 Catalog (HBC NNN)
107-113 A7 --- P00 Persi et al., 2000, J/A+A/357/219 (ISO NNN) (4)
114-120 A7 --- KG2001 Kenyon & Gomez, 2001, J/AJ/121/2673 (KG NNN) (5)
123-128 A6 --- GK2001 Gomez & Kenyon, 2001, J/AJ/121/974 (GK NN) (6)
130-136 A7 --- OTS99 Oasa et al., 1999ApJ...526..336O 1999ApJ...526..336O (OTS NN) (7)
138-142 A5 --- B84 Baud et al., 1984ApJ...278L..53B 1984ApJ...278L..53B (BNNA) (8)
144-153 A10 --- IRAS IRAS designation (HHMMm-DDMM)
155-186 A32 --- Other Other names
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Note (1): Cam1 from table1 and Cam2 from table2, [CCE98] NN in Simbad
Note (2): Ass CHA T 1-NN in Simbad
Note (3): HJM AFF-NN and HJM AF-NN in Simbad
Note (4): ISO-ChaI NNN in Simbad
Note (5): [KG2001] NNN in Simbad
Note (6): [GK2001] NNN in Simbad
Note (7): [OTS99] NN in Simbad
Note (8): BYB NN in Simbad
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Bauer [CDS] 27-Sep-2002