/ftp/cats/aliases/M/./2MASCW



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J/ApJS/211/3        NIR photometry variability in rho Oph        (Parks+, 2014)
The following files can be converted to FITS (extension .fit or fit.gz)
	table1.dat table3.dat
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Query from: http://vizier.cds.unistra.fr/viz-bin/VizieR?-source=J/ApJS/211/3
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drwxr-xr-x 19 cats archive 313 Dec 2 2014 [Up] drwxr-xr-x 3 cats archive 4096 Jan 13 2023 [TAR file] -rw-r--r-- 1 cats archive 477 Dec 19 2022 .message -r--r--r-- 1 cats archive 8789 Jun 1 2014 ReadMe -rw-r--r-- 1 cats archive 1004 Jun 1 2014 +footg5.gif -rw-r--r-- 1 cats archive 2978 Jun 1 2014 +footg8.gif -r--r--r-- 1 cats archive 126225 Apr 4 2014 table1.dat [txt] [txt.gz] [fits] [fits.gz] [html] -r--r--r-- 1 cats archive 6952 Apr 3 2014 table3.dat [txt] [txt.gz] [fits] [fits.gz] [html]
Beginning of ReadMe : J/ApJS/211/3 NIR photometry variability in rho Oph (Parks+, 2014) ================================================================================ Periodic and aperiodic variability in the molecular cloud rho Ophiuchus. Parks J.R., Plavchan P., White R.J., Gee A.H. <Astrophys. J. Suppl. Ser., 211, 3 (2014)> =2014ApJS..211....3P ================================================================================ ADC_Keywords: Photometry, infrared ; Molecular clouds ; Stars, variable ; YSOs Keywords: methods: statistical; stars: individual: rho Ophiuchus Abstract: Presented are the results of a near-IR photometric survey of 1678 stars in the direction of the rho Ophiuchus (rho Oph) star forming region using data from the 2MASS Calibration Database. For each target in this sample, up to 1584 individual J-, H-, and Ks-band photometric measurements with a cadence of  1 day are obtained over three observing seasons spanning  2.5 yr; it is the most intensive survey of stars in this region to date. This survey identifies 101 variable stars with DeltaKs-band amplitudes from 0.044 to 2.31 mag and Delta(J-Ks) color amplitudes ranging from 0.053 to 1.47 mag. Of the 72 young rho Oph star cluster members included in this survey, 79% are variable; in addition, 22 variable stars are identified as candidate members. Based on the temporal behavior of the Ks time-series, the variability is distinguished as either periodic, long time-scale or irregular. This temporal behavior coupled with the behavior of stellar colors is used to assign a dominant variability mechanism. A new period-searching algorithm finds periodic signals in 32 variable stars with periods between 0.49 to 92 days. The chief mechanism driving the periodic variability for 18 stars is rotational modulation of cool starspots while 3 periodically vary due to accretion-induced hot spots. The time-series for six variable stars contains discrete periodic "eclipse-like" features with periods ranging from 3 to 8 days. These features may be asymmetries in the circumstellar disk, potentially sustained or driven by a proto-planet at or near the co-rotation radius. Aperiodic, long time-scale variations in stellar flux are identified in the time-series for 31 variable stars with time-scales ranging from 64 to 790 days. The chief mechanism driving long time-scale variability is variable extinction or mass accretion rates. The majority of the variable stars (40) exhibit sporadic, aperiodic variability over no discernable time-scale. No chief variability mechanism could be identified for these variable stars. Description: The Two Micron All-Sky Survey (2MASS, Skrutskie et al. 2006, Cat. II/246) imaged nearly the entire sky via simultaneous drift scanning in three near-infrared bands (JHKs) between 1997 and 2001. Observations were taken at the northern Mt. Hopkins Observatory and the southern CTIO facility. The source selection in the rho Oph field is similar to that described in Plavchan et al., 2008, Cat. J/ApJS/175/191. Of the 7815 stars identified in the parent sample, 1678 stars have a sufficient number of detections for variability and periodic analysis (listed in table 1). The magnitudes and errors listed are extracted from a co-added image of all calibration scans in that particular band. From the target sample of 1678 stars, 101 stars (6%) are identified as variable (listed in table 3).