J/A+A/581/A66 UV variability and accretion in NGC 2264 (Venuti+, 2015)
UV variability and accretion dynamics in the young open cluster NGC 2264.
Venuti L., Bouvier J., Irwin J., Stauffer J., Hillenbrand L.A., Rebull L.,
Cody A.M., Alencar S.H.P., Micela G., Flaccomio E., Peres G.
<Astron. Astrophys. 581, A66 (2015)>
=2015A&A...581A..66V 2015A&A...581A..66V
ADC_Keywords: Accretion; YSOs; Photometry, CCD; Photometry, SDSS; Ultraviolet
Keywords: accretion, accretion disks - stars: low-mass -
stars: pre-main sequence - stars: variables: T Tauri, Herbig Ae/Be -
open clusters and associations: individual: NGC 2264 -
ultraviolet: stars
Abstract:
Photometric variability is a distinctive feature of young stellar
objects; exploring variability signatures at different wavelengths
provides insight into the physical processes at work in these sources.
We explore the variability signatures at ultraviolet (UV) and optical
wavelengths for several hundred accreting and non-accreting members of
the star-forming region NGC 2264 (∼3Myr).
Description:
Our study aims at characterizing the variability signatures at short
wavelengths for several hundred accreting and non-accreting members of
the star-forming region NGC 2264 (∼3Myr). We performed simultaneous,
2-week-long UV (u-band) and optical (r-band) monitoring of the cluster
with CFHT/MegaCam, with several flux measurements per observing night
to retrace the variability features on timescales from hours to a
couple of weeks. Photometric amplitudes and color behaviors are
explored to investigate the physical origin of the observed
variability in the different cases.
In table2, we present the average u and r photometry measured for
individual sources in our sample, their amplitudes of variability, the
amount of variability measured via the light curve rms and Stetson's
(1996PASP..108..851S 1996PASP..108..851S) J-index indicator, the r-to-(u-r) amplitude
ratio and the uncertainty associated with the latter.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 73 676 Median photometry, variability amplitudes,
light curve rms, J index, and color slopes for
members monitored at CFHT
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See also:
J/AJ/147/82 : Monitoring of disk-bearing stars in NGC 2264 (Cody+, 2014)
J/A+A/570/A82 : Mapping accretion variability in NGC 2264 (Venuti+, 2014)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 6 I06 --- Mon Object identifier (1)
8 A1 --- Flag [*] Variability flag (2)
10 A1 --- Class [c/w] Accreting(c)/non-accreting(w) status (3)
12- 18 A7 --- SpT MK spectral type (4)
20- 24 F5.2 mag umed Median u-band light curve magnitude
26- 30 F5.2 mag rmed Median r-band light curve magnitude
32- 36 F5.3 mag uamp [0.006/4.1] u-band light curve amplitude
38- 42 F5.3 mag ramp [0.005/2.5] r-band light curve amplitude
44- 48 F5.3 mag urms [0.002/4] u-band light curve rms
49- 54 F6.3 mag rrms [0.002/13] r-band light curve rms
56- 61 F6.2 --- Jindex [-5/119] Stetson's (1996PASP..108..851S 1996PASP..108..851S)
variability index J
63- 67 F5.3 --- slope [0/5]? Delta(r)/Delta(u-r) color slope
69- 73 F5.3 --- e_slope [0/1.2]? rms uncertainty on Delta(r)/Delta(u-r)
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Note (1): Object identifiers adopted within the CSI 2264 project
(see Cody et al., 2014AJ....147...82C 2014AJ....147...82C, Cat. J/AJ/147/82).
<CSIMon-NNNNNN> in Simbad.
Note (2): *: object that exhibit a distinct level of variability stronger than
that for field stars, based on the J-index indicator
Note (3): status from Venuti et al. 2014 (J/A+A/570/A82):
c = CTTS (classical T Tauri Star, accreting)
w = WTTS (weak-line T Tauri Star, non-accreting)
Note (4): Spectral type estimates from Venuti et al. (2014A&A...570A..82V 2014A&A...570A..82V,
Cat. J/A+A/570/A82).
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Acknowledgements:
Laura Venuti, laura.venuti(at)ujf-grenoble.fr
(End) Laura Venuti [IPAG, France], Patricia Vannier [CDS] 03-Sep-2015