J/AJ/162/101 K2 ugri & Hα photometry in the Lagoon Nebula (Venuti+, 2021)
Multicolor variability of young stars in the Lagoon Nebula: driving causes and
intrinsic timescales.
Venuti L., Cody A.M., Rebull L.M., Beccari G., Irwin M.J., Thanvantri S.,
Howell S.B., Barentsen G.
<Astron. J., 162, 101-101 (2021)>
=2021AJ....162..101V 2021AJ....162..101V (SIMBAD/NED BibCode)
ADC_Keywords: Nebulae; YSOs; Stars, variable; Photometry, H-alpha;
Photometry, ugriz; Spectral types
Keywords: Young stellar objects; Circumstellar disks; Variable stars
Young star clusters; Multi-color photometry; Time series analysis
Abstract:
Space observatories have provided unprecedented depictions of the many
variability behaviors typical of low-mass, young stars. However, those
studies have so far largely omitted more massive objects (∼2M☉ to
4-5M☉) and were limited by the absence of simultaneous,
multiwavelength information. We present a new study of young star
variability in the ∼1-2Myr old, massive Lagoon Nebula region. Our
sample encompasses 278 young, late B to K-type stars, monitored with
Kepler/K2. Auxiliary u, g, r, i, Hα time-series photometry,
simultaneous with K2, was acquired at the Paranal Observatory. We
employed this comprehensive data set and archival infrared photometry
to determine individual stellar parameters, assess the presence of
circumstellar disks, and tie the variability behaviors to inner disk
dynamics. We found significant mass-dependent trends in variability
properties, with B/A stars displaying substantially reduced levels of
variability compared to G/K stars for any light-curve morphology.
These properties suggest different magnetic field structures at the
surface of early-type and later-type stars. We also detected a dearth
of some disk-driven variability behaviors, particularly dippers, among
stars earlier than G. This indicates that their higher surface
temperatures and more chaotic magnetic fields prevent the formation
and survival of inner disk dust structures corotating with the star.
Finally, we examined the characteristic variability timescales within
each light curve and determined that the day-to-week timescales are
predominant over the K2 time series. These reflect distinct processes
and locations in the inner disk environment, from intense accretion
triggered by instabilities in the innermost disk regions to variable
accretion efficiency in the outer magnetosphere.
Description:
K2 monitored the Lagoon Nebula from 2016 April 21 through July 1. The
campaign was split into two segments, with an interruption of nearly 4
days between May 18 and 22.
The Very Large Survey Telescope (VST)/OmegaCAM run on the Lagoon
Nebula field was executed over a period of 3.5 weeks (2016 June 16
through July 10; Program ID 297.C-5033(A), PI Cody), partly
overlapping with the second half of the K2 run. Seventeen observing
epochs were obtained, distributed over 14 nonconsecutive days. Each
observing block comprised two dithered exposures in the Sloan Digital
Sky Survey (SDSS) u, g, r, i filters (Figure 1) and three dithered
exposures in a narrowband, 659nm Hα filter
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 77 278 *Young stars targeted during K2 Campaign 9
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Note on table1.dat : in the Lagoon Nebula core, and multi-band u, g,
r, i, Hα photometry in the Vega system gathered for each source
with VST/OmegaCAM
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See also:
VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)
II/314 : UKIDSS-DR8 LAS, GCS and DXS Surveys (Lawrence+ 2012)
II/319 : UKIDSS-DR9 LAS, GCS and DXS Surveys (Lawrence+ 2012)
II/321 : IPHAS DR2 Source Catalogue (Barentsen+, 2014)
II/349 : The Pan-STARRS release 1 (PS1) Survey - DR1 (Chambers+, 2016)
IV/34 : K2 Ecliptic Plane Input Catalog (EPIC) (Huber+, 2017)
II/362 : i-band variability of YSOs (Sergison+, 2020)
J/AJ/139/950 : JHKs photometry in ONC (Robberto+, 2010)
J/MNRAS/407/1170 : IRAC photometry of M8 (Kumar+, 2010)
J/A+A/525/A47 : U-band photometry in sigma Orionis region (Rigliaco+, 2011)
J/ApJ/733/50 : Mid-IR photo. monitoring of the ONC (Morales-Calderon+, 2011)
J/MNRAS/415/103 : IPHAS T Tauri candidates in IC 1396 (Barentsen+, 2011)
J/AJ/143/140 : BEST-II periodic variables CoRoT LRa02 field II. (Fruth+, 2012)
J/A+A/551/A107 : X-shooter spectra of 24 young stellar objects (Manara+, 2013)
J/A+A/557/A77 : VR light curves of AA Tau in 2007-2013 (Bouvier+, 2013)
J/A+A/560/A13 : Stellar rotation in h Per (Moraux+, 2013)
J/ApJS/209/27 : MYStIX: the Chandra X-ray sources (Kuhn+, 2013)
J/ApJS/209/31 : The MYStIX IR-Excess Source catalog (MIRES) (Povich+, 2013)
J/ApJS/209/32 : Probable young stars in the MYStIX project (Broos+, 2013)
J/A+A/561/A2 : 36 accreting YSOs emission lines (Alcala+, 2014)
J/AJ/147/82 : Monitoring of disk-bearing stars in NGC 2264 (Cody+, 2014)
J/AJ/148/122 : YSOVAR: infrared photometry in Lynds 1688 (Gunther+, 2014)
J/ApJ/786/97 : Photospheric properties of T Tauri stars (Herczeg+, 2014)
J/MNRAS/440/2036 : VPHAS+ survey synthetic colours (Drew+, 2014)
J/MNRAS/453/1026 : Lagoon Nebula M8 T tauri accretion rates (Kalari+, 2015)
J/A+A/586/A96 : Disk-locking PMS evolutionary tracks (Landin+, 2016)
J/AJ/152/113 : Pleiades mem. with K2 light curves. I. Periods (Rebull+, 2016)
J/ApJ/827/142 : ALMA observations of GKM stars in Upper Sco (Barenfeld+, 2016)
J/ApJ/828/46 : ALMA survey of Lupus protoplanetary disks. I. (Ansdell+, 2016)
J/A+A/600/A20 : Lupus YSOs X-shooter spectroscopy (Alcala+, 2017)
J/A+A/603/A106 : Rotational periods in Cygnus OB2 (Roquette+, 2017)
J/ApJ/839/92 : Praesepe members with K2 light curve data (Rebull+, 2017)
J/AJ/155/196 : Analysis of K2 LCs for members USco & ρOph (Rebull+, 2018)
J/AJ/156/71 : K2 Campaign 2: young disk-bearing stars Sco & Oph (Cody+, 2018)
J/A+A/623/A25 : Photometric and astrometric study of NGC 6530 (Damiani+, 2019)
J/A+A/623/A159 : NGC6530 member param. from Gaia-ESO survey (Prisinzano+ 2019)
J/ApJ/875/51 : Mass accretion rates PMS stars. VI. LH95 in LMC (Biazzo+, 2019)
J/AJ/159/273 : Taurus members & nonmembers with K2 data (Rebull+, 2020)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Name K2 EPIC identifier or common name if not in EPIC
11- 29 A19 --- 2MASS 2MASS Identifier
31- 37 A7 --- SpT Estimated Spectral type (1)
39- 41 F3.1 mag AVmag [0/3.8]? Estimated extinction
43- 43 A1 --- Disk Disk flag (2)
45- 49 F5.2 mag umag [8.24/20.5]? VST/OmegaCAM u-band magnitude
51- 55 F5.2 mag gmag [8.27/20]? VST/OmegaCAM g-band magnitude
57- 61 F5.2 mag rmag [8.35/18.1]? VST/OmegaCAM r-band magnitude
63- 67 F5.2 mag imag [8.39/18.1]? VST/OmegaCAM i-band magnitude
69- 73 F5.2 mag Hamag [8.29/18.2]? VST/OmegaCAM narrow-band Hα
magnitude
75- 77 A3 --- Class K2 light curve class (3)
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Note (1): Approximate spectral class derived for each target as described in
Sect.3.1. The mention of "early-" encompasses spectral subclasses 0 to
3, "mid-" corresponds to subclasses 4 to 6, and "late-" identifies
subclasses 7 to 9.
Note (2): Possible flag values are "Y" if the target is a disk-bearing YSO,
"N" if the target is a disk-free object, and "?" if the spectral energy
distribution of the object and the disk indicators described in Sect.3.2
provide contrasting or incomplete information. In our analysis, we
consider objects labeled "?" as disk candidate YSOs.
Note (3): Class as follows:
P = periodic (79 occurrences)
QPS = quasi-periodic symmetric (77 occurrences)
S = stochastic (17 occurrences)
B = burster (5 occurrences)
QPD = quasi-periodic dipper (10 occurrences)
APD = aperiodic dipper (7 occurrences)
MP = multi-periodic (40 occurrences)
EB = eclipsing binary (7 occurrences)
N = non-variable (20 occurrences)
U = unclassifiable (16 occurrences)
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 01-Dec-2021