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J/ApJS/175/191   Variables from 2MASS calibration fields     (Plavchan+, 2008)

Near-infrared variability in the 2MASS calibration fields: a search for planetary transit candidates. Plavchan P., Jura M., Kirkpatrick J.D., Cutri R.M., Gallagher S.C. <Astrophys. J. Suppl. Ser., 175, 191-228 (2008)> =2008ApJS..175..191P
ADC_Keywords: Stars, variable ; Photometry, infrared Keywords: binaries: eclipsing - methods: statistical - stars: variables: other Abstract: The Two Micron All Sky Survey (2MASS) photometric calibration observations cover ∼6 square degrees on the sky in 35 "calibration fields", each sampled in nominal photometric conditions between 562 and 3692 times during the 4 years of the 2MASS mission. We compile a catalog of variables from the calibration observations to search for M dwarfs transited by extrasolar planets. We present our methods for measuring periodic and nonperiodic flux variability. From 7554 sources with apparent Ks magnitudes between 5.6 and 16.1, we identify 247 variables, including extragalactic variables and 23 periodic variables. We have discovered three M dwarf eclipsing systems, including two candidates for transiting extrasolar planets. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table2.dat 72 7554 Sample Properties table4.dat 97 247 Variables table5.dat 97 58 Candidate Variables table8.dat 81 23 Periodic Variables table13.dat 95 247 Classification of Variables table14.dat 95 58 Classification of Candidate Variables
See also: V/121 : Catalog of DMS-type eclipsing binaries (Svechnikov+, 1999) II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003) J/A+A/380/590 : 30 DENIS late-M dwarfs between 15 and 30pc (Phan-Bao+, 2001) J/A+A/390/267 : The CORALIE survey for extrasolar planets VIII (Udry+, 2002) Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 16 A16 --- 2MASS PSC source identification (HHMMSSss+DDMMSSs) (1) 18- 22 I5 --- Field Field number 24- 27 I4 --- Ndet Number of detections (2) 29- 35 F7.4 mag Jmag 2MASS J band magnitude (3) 37- 42 F6.4 mag e_Jmag Uncertainty in Jmag 44- 50 F7.4 mag Hmag 2MASS H band magnitude (3) 52- 57 F6.4 mag e_Hmag Uncertainty in Hmag 59- 65 F7.4 mag Ksmag 2MASS K_s_ band magnitude (3) 67- 72 F6.4 mag e_Ksmag Uncertainty in Ksmag
Note (1): We note that all Cal-PSWDB detections have unique identifiers, and we spatially associate each with the PSC catalog source and designation in our sample (Section 2.2). Note (2): Either in J, H or Ks (equivalent to Nm,n in text). See Table 1 and Section 3.1 for discussion. Note (3): Unweighted mean apparent magnitude of Cal-PSWDB photometry (equivalent to mn in text).
Byte-by-byte Description of file: table[45].dat
Bytes Format Units Label Explanations
1- 16 A16 --- 2MASS PSC source identification (HHMMSSss+DDMMSSs) 18- 19 I2 % Prob ? Probability of intrinsic variability (1) 21 I1 --- o_Flags Number of Flags 23- 29 I07 --- Flags Variability flags (G1) 31 A1 --- l_Jflm The 3σ limit flag on Jflm 32- 37 F6.4 mag Jflm 2MASS J band flicker magnitude (2) 39- 44 F6.4 mag e_Jflm ? Uncertainty in Jflm 46 A1 --- l_Hflm The 3σ limit flag on Hflm 47- 52 F6.4 mag Hflm 2MASS H band flicker magnitude (2) 54- 59 F6.4 mag e_Hflm ? Uncertainty in Hflm 61 A1 --- l_Ksflm The 3σ limit flag on Ksflm 62- 68 F7.4 mag Ksflm 2MASS K_s_ band flicker magnitude (2) 70- 75 F6.4 mag e_Ksflm ? Uncertainty in Ksflm 77- 80 I4 --- neJ ? 2MASS J band excursion number (3) 82- 85 I4 --- neH ? 2MASS H band excursion number (3) 87- 90 I4 --- neKs ? 2MASS K_s_ band excursion number (3) 92- 97 F6.3 --- S-Ind Stetson Index (4)
Note (1): For Table 5, estimated probability that the observed variability is intrinsic to the source, rather than due to seeing variations. See Section 3.3.1 for discussion. Note (2): Magnitudes of "flickering" variability for flags 1-3. 3σ upper-limits and detections are listed, but 5σ is required to trigger the variability flags. See Section 3.2.1. Note (3): The number of excursions for flags 4-6. The "excursive" scan groups need not be the same between bands. A positive number corresponds to the largest excursion being fainter than the mean magnitude, and vice-versa for a negative number. See Section 3.2.2. Note (4): A Stetson Index in excess of 0.2 triggers the Stetson variability flag. See Section 3.2.3.
Byte-by-byte Description of file: table8.dat
Bytes Format Units Label Explanations
1- 16 A16 --- 2MASS 2MASS-PSC Name (HHMMSSss+DDMMSSs) 18- 24 I07 --- Flags Variability flags (G1) 26- 33 F8.6 d Per Period (1) 35 A1 --- f_Per [eg] Note on the period (2) 37- 43 F7.5 d Per2 ? 2d Period for eclipsing binary (3) 45- 49 F5.3 --- Phase Phase (4) 51- 55 I5 --- Field Field 57- 79 A23 --- Type Object Type (5) 81 A1 --- f_Type [f] Flag on object type (6)
Note (1): Uncertainty in period is approximately ±1 in the least significant digit. Note (2): Flag as follows: e = Period from A. Becker g = The identification of this period is uncertain. The object exhibits variability on a 3 day timescale, but the observed variability is not entirely consistent with this period derived from our analysis. Note (3): When two periods are quoted, the system is an eclipsing binary with indistinguishable eclipses or an inconclusive object type. See Figs. 22-44 for light curves and 45-67 for color curves of these objects folded to these periods. Note (4): Corresponding phase in Figs. 22-67 for the Julian Date=2450000.0. When two periods are listed, this phase is for the larger period, which is also the one plotted in Figs. 33, 34, and 38. Note (5): Object type inferred from period, colors, light curve appearance, and Galactic latitude. Sinusoidal objects and objects without any listed object type have inconclusive identifications from available data. Note (6): See Section 4.2.1 for discussion of these object (newly discovered detached eclipsing binaries with M dwarf components).
Byte-by-byte Description of file: table1[34].dat
Bytes Format Units Label Explanations
1- 16 A16 --- 2MASS PSC source identification (HHMMSSss+DDMMSSs) 18- 23 F6.3 mag Ksmag 2MASS Ks band magnitude 25- 29 F5.2 mag B-Ks ? The (B-Ks) color index 31- 36 F6.3 mag H-Ks The 2MASS (H-Ks) color index 38- 42 F5.3 mag J-H The 2MASS (J-H) color index 44 A1 --- Cat Color category (1) 46- 95 A50 --- Note Note on Name (2)
Note (1): Categories "A","B","C","D","E" and "F" corresponds to sources in |b|>20 fields as follows: A = sources with B-Ks<4.97 and H-Ks<0.2; B = sources with B-Ks<4.97 and 0.2<H-Ks<0.7; C = B-Ks<4.97 and H-Ks>0.8; D = B-Ks>4.97, excluding category "F" sources; E = sources have no identified B counterpart and typically H-Ks>0.2; F = sources have colors consistent with evolved giants. See Figures 68 and 69, and Section 4.3. G = sources in |b|<20° fields. Note (2): This column lists such information as any SIMBAD object identification, any SDSS DR5 object identification (e.g. "STAR"), any coincident extragalactic source name, a period if the source is periodic, and the type of object if a reasonable determination can be made (e.g. "eclipsing binary"). This list is not complete.
Global notes: Note (G1): The seven variability "flags" are defined in Section 3.2; each of the seven flags takes the value 1 for a variability identified for this flag, and 0 otherwise. The meaning of the flags are, from left to right: [1-3] = >5σ flickering in J, H and Ks: the standard deviation of the source variability that reproduces the observed photometric scatter in excess of the expected photometric scatter (equivalent to σvar,m,n±νvar,m,n in the text). [4-6] = the number of excursions in J, H and Ks: individual scan groups that are >5σ deviant from the mean magnitude. 7 = variables with Stetson indices in excess of 0.2.
History: From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 17-Jun-2009
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

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