J/ApJ/753/149 YSOVAR: six eclipsing binaries in Orion (Morales-Calderon+, 2012)
YSOVAR: six pre-main-sequence eclipsing binaries in the Orion Nebula Cluster.
Morales-Calderon M., Stauffer J.R., Stassun K.G., Vrba F.J., Prato L.,
Hillenbrand L.A., Terebey S., Covey K.R., Rebull L.M., Terndrup D.M.,
Gutermuth R., Song I., Plavchan P., Carpenter J.M., Marchis F.,
Garcia E.V., Margheim S., Luhman K.L., Angione J., Irwin J.M.
<Astrophys. J., 753, 149 (2012)>
=2012ApJ...753..149M 2012ApJ...753..149M
ADC_Keywords: Binaries, eclipsing ; Stars, pre-main sequence ; Spectral types ;
Photometry, infrared
Keywords: binaries: eclipsing; open clusters and associations: Orion;
stars: pre-main sequence; stars: variables: general
Abstract:
Eclipsing binaries (EBs) provide critical laboratories for empirically
testing predictions of theoretical models of stellar structure and
evolution. Pre-main-sequence (PMS) EBs are particularly valuable, both
due to their rarity and the highly dynamic nature of PMS evolution,
such that a dense grid of PMS EBs is required to properly calibrate
theoretical PMS models. Analyzing multi-epoch, multi-color light
curves for ∼2400 candidate Orion Nebula Cluster (ONC) members from our
Warm Spitzer Exploration Science Program YSOVAR, we have identified 12
stars whose light curves show eclipse features. Four of these 12 EBs
are previously known. Supplementing our light curves with follow-up
optical and near-infrared spectroscopy, we establish two of the
candidates as likely field EBs lying behind the ONC. We confirm the
remaining six candidate systems, however, as newly identified ONC PMS
EBs. These systems increase the number of known PMS EBs by over 50%
and include the highest mass (θ1 Ori E, for which we provide a
complete set of well-determined parameters including component masses
of 2.807 and 2.797M☉) and longest-period
(ISOY J053505.71-052354.1, P∼20 days) PMS EBs currently known. In two
cases (θ1 Ori E and ISOY J053526.88-044730.7), enough
photometric and spectroscopic data exist to attempt an orbit solution
and derive the system parameters. For the remaining systems, we
combine our data with literature information to provide a preliminary
characterization sufficient to guide follow-up investigations of these
rare, benchmark systems.
Description:
In this paper, we report the identification and initial
characterization of six new pre-main sequence EB (eclipsing binary)
candidates in the ONC, discovered as part of the YSOVAR (Young Stellar
Object VARiability) Spitzer Exploration Science program
(Morales-Calderon et al. 2011, Cat. J/ApJ/733/50).
To complement our Spitzer data, we obtained contemporaneous Ic and J
photometry (in 2009), usually for smaller areas within the Spitzer
mosaic. The main source of J-band monitoring data was the United
Kingdom Infrared Telescope Wide Field Camera (UKIRT/WFCAM). For the Ic
band, the New Mexico State University/Apache Point Observatory
(NMSU/APO) 1m telescope and NasaCam at the 31" telescope at Lowell
Observatory contributed the bulk of the monitoring data. We performed
differential aperture photometry on the ground-based data.
To confirm the identification of the new EBs and to refine
measurements of their orbital periods and eclipse shapes, we obtained
additional photometry in 2010 and 2011. See section 3 for further details.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 126 8 New eclipsing binary candidates
table6.dat 30 232 θ1 Ori E time series at [3.6] and [4.5]
table7.dat 30 4607 ISOY J0535-0447 time series at [3.6], [4.5],
J, and Ic bands
table8.dat 30 310 ISOY J0535-0522 time series at [3.6], [4.5],
and Ic bands
table9.dat 30 2759 ISOY J0535-0523 time series at [3.6], [4.5],
and Ic bands
table10.dat 30 378 ISOY J0534-0454 time series at [3.6], [4.5],
and J bands
table11.dat 30 2399 ISOY J0535-0525 time series at [3.6], [4.5],
J, and Ic bands
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See also:
II/171 : Parenago Catalog of Stars in Orion Nebula (Parenago 1954)
J/ApJS/207/10 : HST Treasury Program on the ONC (Robberto+, 2013)
J/AJ/144/192 : Orion A & B Spitzer survey. I. YSO catalog (Megeath+, 2012)
J/AJ/142/60 : Palomar Transient Factory Orion Project (Van Eyken+, 2011)
J/ApJ/733/50 : MIR phot. monitoring of the ONC (Morales-Calderon+, 2011)
J/AJ/139/950 : JHKs photometry in ONC (Robberto+, 2010)
J/MNRAS/400/603 : New variables in ONC (Parihar+, 2009)
J/A+A/508/1313 : Orion pre-main sequence RIJH light curves (Frasca+, 2009)
J/ApJ/671/605 : NGC 2264 and ONC PMS stars in the infrared (Cieza+, 2007)
J/AJ/128/787 : Chandra Orion flanking fields data (Ramirez+, 2004)
J/AJ/121/3160 : JHK photometry near the Trapezium region (Carpenter+, 2001)
J/AJ/121/1676 : ONC low-mass stars photometry (Rebull+, 2001)
J/A+A/375/130 : New PMS spectroscopic binaries in Orion (Covino+ 2001)
J/AJ/113/1733 : Orion Nebula Cluster population (Hillenbrand 1997)
http://ysovar.ipac.caltech.edu/ : YSOVAR project home page
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- --- [ISOY] (Initial Spitzer Orion YSO)
6- 24 A19 --- ISOY Initial Spitzer Orion YSO source name
(JHHMMSS.ss+DDMMSS.s)
26 A1 --- n_Name [i] i=Probable field eclipsing binary
28- 50 A23 --- Name Most common name (1)
52- 56 F5.2 mag Vmag [12.1/19.1]? V-band magnitude
58 A1 --- r_Vmag [cd] Origin of Vmag (2)
60- 64 F5.2 mag Icmag [11/15.7]? Ic-band magnitude
66 A1 --- r_Icmag [cd] Origin of Icmag (2)
68- 72 F5.2 mag Jmag [6.6/14.9]? J-band magnitude (3)
74- 78 F5.2 mag Hmag [6.2/14.1] H-band magnitude (3)
80- 84 F5.2 mag Ksmag [6/13.8] Ks-band magnitude (3)
86- 90 F5.2 mag [3.6] [6.9/13.6] 3.6um band magnitude (4)
92- 96 F5.2 mag [4.5] [6.5/13.5] 4.5um band magnitude (4)
98-102 F5.2 mag [5.8] [6.1/13.2]? 5.8um band magnitude (4)
104-107 F4.2 mag [8.0] [9.2/9.3]? 8.0um band magnitude (4)
109-113 A5 --- SpT MK spectral type from this work (unless flag)
115 A1 --- r_SpT [cdg] Origin of SpT (2)
117-126 F10.7 d Per [0.54/20.49]? Period from this work
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Note (1): Most common names from the literature searchable in SIMBAD database:
[H97b], Hillenbrand (1997, Cat. J/AJ/113/1733); JW, Jones & Walker
(1988AJ.....95.1755J 1988AJ.....95.1755J); [RRS2004], Ramirez et al. (2004, Cat. J/AJ/128/787),
Parenago: Parenago (1954, Cat. II/171).
Note (2): Reference as follows:
c = Rebull (2001, Cat. J/AJ/121/1676; <[R2001] NNNN> in Simbad)
d = Hillenbrand (1997, Cat. J/AJ/113/1733)
g = Costero et al. (2006IAUC.8669....2C 2006IAUC.8669....2C)
Note (3): JHK magnitudes from Carpenter et al. (2001, Cat. J/AJ/121/3160;
<[CHS2001] NNNNN> in Simbad).
Note (4): Spitzer/IRAC magnitudes from S.T. Megeath et al. (2012,
Cat. J/AJ/144/192; <[MGM2012] NNNN> in Simbad).
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Byte-by-byte Description of file: table[6789].dat table10.dat table11.dat
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Bytes Format Units Label Explanations
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1- 13 F13.5 d HJD Heliocentric Julian Date
15- 17 A3 --- Filt "3.6", "4.5", "J" or "I" filter
19- 24 F6.3 mag mag [6.4/15.6] Magnitude in Filt
26- 30 F5.3 mag e_mag [0.002/0.2] mag uncertainty
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 18-Feb-2014