J/ApJ/733/50 Mid-IR photometric monitoring of the ONC (Morales-Calderon+, 2011)
YSOVAR: the first sensitive, wide-area, mid-infrared photometric monitoring of
the Orion Nebula Cluster.
Morales-Calderon M., Stauffer J.R., Hillenbrand L.A., Gutermuth R.,
Song I., Rebull L.M., Plavchan P., Carpenter J.M., Whitney B.A., Covey K.,
de Oliveira C.A., Winston E., McCaughrean M.J., Bouvier J., Guieu S.,
Vrba F.J., Holtzman J., Marchis F., Hora J.L., Wasserman L.H., Terebey S.,
Megeath T., Guinan E., Forbrich J., Huelamo N., Riviere-Marichalar P.,
Barrado D., Stapelfeldt K., Hernandez J., Allen L.E., Ardila D.R., Bayo A.,
Favata F., James D., Werner M., Wood K.
<Astrophys. J., 733, 50 (2011)>
=2011ApJ...733...50M 2011ApJ...733...50M
ADC_Keywords: Clusters, open ; Photometry, infrared ; YSOs ; Stars, variable
Keywords: circumstellar matter - stars: variables: general -
open clusters and associations: individual (Orion) -
stars: pre-main sequence - stars: protostars
Abstract:
We present initial results from time-series imaging at infrared
wavelengths of 0.9deg2 in the Orion Nebula Cluster (ONC). During
Fall 2009 we obtained 81 epochs of Spitzer 3.6 and 4.5um data over 40
consecutive days. We extracted light curves with ∼3% photometric
accuracy for ∼2000 ONC members ranging from several solar masses down
to well below the hydrogen-burning mass limit. For many of the stars,
we also have time-series photometry obtained at optical (Ic) and/or
near-infrared (JKs) wavelengths. Our data set can be mined to
determine stellar rotation periods, identify new pre-main-sequence
eclipsing binaries, search for new substellar Orion members, and help
better determine the frequency of circumstellar disks as a function of
stellar mass in the ONC. Our primary focus is the unique ability of
3.6 and 4.5um variability information to improve our understanding of
inner disk processes and structure in the Class I and II young stellar
objects (YSOs). In this paper, we provide a brief overview of the
YSOVAR Orion data obtained in Fall 2009 and highlight our light curves
for AA-Tau analogs -YSOs with narrow dips in flux, most probably due
to disk density structures passing through our line of sight. Detailed
follow-up observations are needed in order to better quantify the
nature of the obscuring bodies and what this implies for the structure
of the inner disks of YSOs.
Description:
Our GO6 Exploration Science program YSOVAR (Young Stellar Object
Variability) provides the first large-scale survey of mid-IR
photometric variability of YSOs. In Fall 2009, we used ∼250hr of warm
Spitzer observing time to monitor ∼0.9deg2 of the ONC at 3.6 and
4.5um.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
stars.dat 46 2067 The ONC stars sample (table added by CDS with
coordinates from table 2 in the published version)
table2.dat 58 351324 Time series at the [3.6] and [4.5] IRAC bands
for the ONC stars
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See also:
J/AJ/142/60 : Palomar Transient Factory Orion Project (Van Eyken+, 2011)
J/AJ/139/950 : JHKs photometry in ONC (Robberto+, 2010)
J/A+A/515/A13 : Very low mass objects in ONC (Rodriguez-Ledesma+, 2010)
J/ApJ/676/1109 : Velocities of stars in the ONC (Furesz+, 2008)
J/ApJ/671/605 : NGC 2264 and ONC PMS stars in the infrared (Cieza+, 2007)
J/ApJS/160/353 : Membership of the Orion nebula population (Getman+, 2005)
http://ysovar.ipac.caltech.edu/ : YSOVAR project website
Byte-by-byte Description of file: stars.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- --- [ISOY_]
6- 24 A19 --- ISOY Object identification (JHHMMSS.ss+DDMMSS.s)
26- 35 F10.7 deg RAdeg [83.5/84.1] Right Ascension in decimal
degrees (J2000)
37- 46 F10.7 deg DEdeg [-6.1/-4.6] Declination in decimal degrees
(J2000)
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 A5 --- --- [ISOY_]
6- 24 A19 --- ISOY Object identification (JHHMMSS.ss+DDMMSS.s)
26- 39 F14.8 d MJD [55127.4/55166.7] Modified Julian date of the
observation
41- 45 A5 --- Band [IRAC1/IRAC2] Spitzer/IRAC band (IRAC1=3.6um or
IRAC2=4.5um)
47- 52 F6.3 mag mag [5.073/16.645] Observed magnitude in Band
54- 58 F5.3 mag e_mag Error in mag
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 06-Nov-2012