J/ApJ/921/165 Members of Sh 2-190 and PMS variables (Sinha+, 2021)
Photometric variability of the pre-main-sequence stars toward the Sh 2-190
region.
Sinha T., Sharma S., Panwar N., Matsunaga N., Ogura K., Kobayashi N.,
Yadav R.K., Ghosh A., Pandey R., Bisht P.S.
<Astrophys. J., 921, 165 (2021)>
=2021ApJ...921..165S 2021ApJ...921..165S
ADC_Keywords: Stars, variable; YSOs; Photometry, UBVRI; Stars, ages;
Stars, masses; Proper motions; X-ray sources
Keywords: Variable stars ; Pre-main sequence
Abstract:
We present the results from our time-series imaging data taken with
the 1.3m Devasthal fast optical telescope and 0.81m Tenagara telescope
in V, Rc, and Ic bands covering an area of ∼18.4x18.4 toward the
star-forming region Sh 2-190. This photometric data helped us to
explore the nature of the variability of pre-main-sequence (PMS)
stars. We have identified 85 PMS variables, i.e., 37 Class II and
48 Class III sources. Forty-five of the PMS variables show periodicity
in their light curves. We show that the stars with thicker disks and
envelopes rotate slower and exhibit larger photometric variations
compared to their diskless counterparts. This result suggests that
rotation of the PMS stars is regulated by the presence of
circumstellar disks. We also found that the periods of the stars show
a decreasing trend with increasing mass in the range of
∼0.5-2.5M☉. Our result indicates that most of the variability in
Class II sources is ascribed to the presence of a thick disk, while
the presence of cool spots on the stellar surface causes the
brightness variation in Class III sources. X-ray activities in the PMS
stars were found to be at the saturation level reported for the
main-sequence stars. The younger counterparts of the PMS variables
show less X-ray activity, hinting at a less significant role of a
stellar disk in X-ray generation.
Description:
Optical photometric observations of Sh 2-190 were taken in the V,
Rc, and Ic bands from 2012 September to 2013 March with the 0.81m
Tenagara Automated Telescope (South Arizona) and from 2018 December to
2020 February using the 1.3m Devasthal Fast Optical Telescope (DFOT,
India).
The FITS files of an 18.4'x18.4' FOV in the zg and zr bands were also
downloaded from the Zwicky Transient Facility (ZTF) archive, giving
time-series images from 2018 June to 2019 March.
In total, the field was observed on 96, 94, 94, 107, and 107 nights in
V, Rc , Ic , zg, and zr bands, respectively, and we use 354, 344,
327, 107, and 107 frames of the five bands in our analysis.
Objects:
----------------------------------------------------------
RA (ICRS) DE Designation(s)
----------------------------------------------------------
02 32 50.39 +61 28 15.5 SH 2-190 = RAFGL 333
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File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2.dat 113 308 Sh 2-190 members catalog
table3.dat 226 85 PMS variables and their physical parameters
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See also:
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
II/293 : GLIMPSE Source Catalog (I + II + 3D) (IPAC 2008)
II/311 : WISE All-Sky Data Release (Cutri+ 2012)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
I/347 : Distances to 1.33 billion stars in Gaia DR2 (Bailer-Jones+, 2018)
J/A+AS/133/387 : NGC 1817 and NGC 1807 proper motions (Balaguer-Nunnez+ 1998)
J/AJ/116/1816 : JHKLMNOPQ photometry in Orion cluster (Hillenbrand+, 1998)
J/A+A/396/513 : Stellar Rotation in the Orion Nebula Cluster (Herbst+, 2002)
J/A+A/397/147 : Activity-rotation relationship in stars (Pizzolato+ 2003)
J/A+A/417/557 : Rotation & variability of PMS Stars in NGC 2264 (Lamm, 2004)
J/AJ/127/2228 : VRI photometry of PMS stars in NGC 2264 OB (Makidon+, 2004)
J/A+A/430/1005 : VRIHα photometry of NGC 2264 variables (Lamm+, 2005)
J/MNRAS/358/341 : Ic photometry of IC 348 (Littlefair+, 2005)
J/ApJ/646/297 : Spitzer obs. of pre-main-sequence stars (Rebull+, 2006)
J/A+A/463/1017 : B and V light curves of AA Tau (Bouvier+, 2007)
J/A+A/479/827 : UBVR LCs of weak-line T Tauri stars (Grankin+, 2008)
J/MNRAS/396/964 : T Tauri in and around bright-rimmed clouds (Chauhan+, 2009)
J/A+A/502/883 : I phot. of low mass ONC stars (Rodriguez-Ledesma+, 2009)
J/other/A+ARV/17.251 : Stars observed with Doppler imaging (Strassmeier, 2009)
J/ApJS/191/389 : Photometric monitoring in σ Ori cluster (Cody+, 2010)
J/MNRAS/403/545 : Young stars in Cepheus OB3b (Littlefair+, 2010)
J/A+A/515/A13 : Very low mass objects in ONC (Rodriguez-Ledesma+, 2010)
J/A+A/539/A64 : X-ray data for IC 348 young stars (Alexander+, 2012)
J/ApJ/747/51 : Lagoon Nebula stars. I. Rotation periods (Henderson+, 2012)
J/ApJ/755/20 : YSOs population of Sh2-294 with Spitzer/IRAC (Samal+, 2012)
J/MNRAS/430/1433 : NGC 2264 members periods with CoRoT (Affer+, 2013)
J/A+A/557/A77 : VR light curves of AA Tau in 2007-2013 (Bouvier+, 2013)
J/MNRAS/432/3445 : YSOs on HII complex Sh2-252 (Jose+, 2013)
J/A+A/554/A3 : Vilnius photometry of IC1805 stars (Straizys+, 2013)
J/AJ/147/82 : Monitoring of disk-bearing stars in NGC 2264 (Cody+, 2014)
J/MNRAS/443/1614 : YSOs in BRC 5, 7 and 39 (Panwar+, 2014)
J/ApJS/211/3 : NIR photometry variability in ρ Oph (Parks+, 2014)
J/ApJS/213/1 : The MSFRs Omnibus X-ray Catalog (MOXC) (Townsley+, 2014)
J/MNRAS/462/2396 : Time-series photometry of IC 348 (Fritzewski+, 2016)
J/MNRAS/468/2684 : IC1805 YSOs (Panwar+, 2017)
J/A+A/603/A106 : Rotational periods in Cygnus OB2 (Roquette+, 2017)
J/MNRAS/467/2943 : NGC 7538 region YSOs (Sharma+, 2017)
J/ApJS/230/3 : Optical & Spitzer photometry in IC 1805 (Sung+, 2017)
J/A+A/599/A23 : Accretion-rotation connection in NGC 2264 (Venuti+, 2017)
J/A+A/619/A41 : Photometric variability of massive YSOs (Teixeira+, 2018)
J/A+A/627/A135 : VRI photometry of IC5070 variable stars (Bhardwaj+, 2019)
J/MNRAS/482/658 : NGC 1893 young open cluster rich in var. stars (Xue+, 2019)
J/ApJ/896/29 : Deep UBVRI photometry of NGC6910 members (Kaur+, 2020)
J/ApJ/891/81 : Deep optical and IR photometry of Sh2-305 (Pandey+, 2020)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- ID Member ID, M### sequential identifier
(numbers from 1 to 308)
6- 14 F9.6 deg RAdeg [37.85/38.5] Right Ascension (J2000)
16- 24 F9.6 deg DEdeg [61.3/61.61] Declination (J2000)
26- 31 F6.3 mag Imag [12.39/19.33]? I-band magnitude,
from Sung+ (2017, J/ApJS/230/3)
33- 37 F5.3 mag e_Imag [0/0.061]? Uncertainty in Imag
39- 44 F6.3 mag Rmag [12.79/21]? R-band magnitude,
from Sung+ (2017, J/ApJS/230/3)
46- 50 F5.3 mag e_Rmag [0/0.035]? Uncertainty in Rmag
52- 57 F6.3 mag Vmag [13.2/22.8]? V-band magnitude
from Sung+ (2017, J/ApJS/230/3)
59- 63 F5.3 mag e_Vmag [0/0.1]? Uncertainty in Vmag
65- 69 F5.2 mas/yr pmRA [-4.8/7.7] Proper Motion, Right Ascension,
Gaia DR2
71- 74 F4.2 mas/yr e_pmRA [0.02/2] Uncertainty in pmRA
76- 80 F5.2 mas/yr pmDE [-4.8/3.5] Proper Motion, Declination, Gaia DR2
82- 85 F4.2 mas/yr e_pmDE [0.03/2.6] Uncertainty in pmDE
87- 91 F5.2 mas Plx [-3.5/2] Parallax, Gaia DR2
93- 96 F4.2 mas e_Plx [0.02/2.08] Uncertainty in Plx
98-100 I3 % Prob [80/100] Membership probability
102-107 F6.3 mag Gmag [7.87/20.9] Gaia DR2 G-band magnitude
109-113 F5.3 mag BP-RP [0.67/2.74]? Gaia DR2 BP-RP color index
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Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- ID Variable ID, V### sequential identifier
(numbers among 1 to 134)
5- 6 A2 --- f_ID [* ] ** = not explained in the paper
8- 16 F9.6 deg RAdeg [37.9/38.5] Right Ascension (J2000)
18- 26 F9.6 deg DEdeg [61.3/61.6] Declination (J2000)
28- 33 F6.3 mag Vmag [15.8/22.5]? V-band magnitude
from Sung+ (2017, J/ApJS/230/3)
35- 39 F5.3 mag e_Vmag [0.002/0.4]? Uncertainty in Vmag
41- 46 F6.3 mag Rmag [14.8/20.9]? R-band magnitude
from Sung+ (2017, J/ApJS/230/3)
48- 52 F5.3 mag e_Rmag [0/0.09]? Uncertainty in Rmag
54- 59 F6.3 mag Imag [13.97/19.35]? I-band magnitude
from Sung+ (2017, J/ApJS/230/3)
61- 65 F5.3 mag e_Imag [0.001/0.2]? Uncertainty in Imag
67- 73 F7.3 d Per [0.48/24.6]? Period
75- 81 F7.3 d e_Per [0.001/1.1]? Uncertainty in Per
83- 86 F4.2 mag Amp [0.1/2.2] Amplitude
88- 91 F4.2 mag e_Amp [0/0.08] Uncertainty in Amp
93- 99 F7.3 mag d(Ic-Ks) [-1.14/2.1]? Color excess in Ic-Ks
101-107 F7.3 mag e_d(Ic-Ks) [0.02/0.2]? Uncertainty in d(Ic-Ks)
109-115 F7.3 mag 3.6-4.5 [0.01/0.9]? Spitzer IRAC 3.6um-4.5um color
index
117-123 F7.3 mag e_3.6-4.5 [0.014]? Uncertainty in 3.6-4.5
125-128 F4.1 Myr Age1 [0.1/10] Age from CMD
130-132 F3.1 Myr e_Age1 [0/2.2] Uncertainty in Age
134-136 F3.1 Msun Mstar1 [0.3/3] Mass from CMD
138-140 F3.1 Msun e_Mstar1 [0/0.2] Uncertainty in Mstar1
143-144 I2 --- Nsed [7/14]? Number of data points in SED fit
146-150 F5.1 --- chi2 [1/98]? χ2 of SED fit
152-156 F5.1 Myr Age2 [0.1/6.4]? Age from SED fitting
158-162 F5.1 Myr e_Age2 [0.1/3.2]? Uncertainty in Age2
164-168 F5.1 Msun Mstar2 [0.9/6]? Mass from SED fitting
170-174 F5.1 Msun e_Mstar2 [0.2/2]? Uncertainty in Mstar2
176-183 E8.1 Msun Mdisk [6.3e-6/0.08]? Disk mass
185-192 E8.1 Msun e_Mdisk [1e-5/0.1]? Uncertainty in Mdisk
194-201 E8.1 Msun/yr Macc [3e-12/2.6e-6]? Disk mask accretion rate
203-210 E8.1 Msun/yr e_Macc [4.9e-12/4.3e-6]? Uncertainty in Macc
212-216 F5.2 [Lsun] logLx [-4.2/-1.4] log of X-ray luminosity (1)
218-226 A9 --- Class Classification (2)
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Note (1): X-ray data were taken from "The massive Star-forming Regions
Omnibus X-ray Catalog" (Townsley+ 2014, J/ApJS/213/1); see Section 4.7.
Note (2): Classification as follows:
WTT = weak-line T Tauri stars; EW≤10Å (28 occurrences)
CTT = classical T Tauri stars; EW>10Å (20 occurrences)
Class III = Class III objects; depleted or no accretion disks (21 occurrences)
Class II = Class II objects; thick circumstellar disk and residual envelope
(16 occurrences)
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 24-Feb-2023