J/MNRAS/476/2813 NGC 2282 photometry of variable stars (Dutta+, 2018)
Optical photometric variable stars towards the Galactic H II region NGC 2282.
Dutta S., Mondal S., Joshi S., Jose J., Das R., Ghosh S.
<Mon. Not. R. Astron. Soc., 476, 2813-2824 (2018)>
=2018MNRAS.476.2813D 2018MNRAS.476.2813D (SIMBAD/NED BibCode)
ADC_Keywords: H II regions ; Stars, variable ; Photometry, infrared ;
Photometry, UBVRI
Keywords: methods: observational - stars: formation - stars: pre-main-sequence -
stars: variables: general
Abstract:
We report here CCD I-band time series photometry of a young (2-5Myr)
cluster NGC 2282, in order to identify and understand the variability
of pre-main-sequence (PMS) stars. The I-band photometry, down to
∼20.5mag, enables us to probe the variability towards the lower
mass end (∼0.1M☉) of PMS stars. From the light curves of
1627 stars, we identified 62 new photometric variable candidates.
Their association with the region was established from Hα
emission and infrared (IR) excess. Among 62 variables, 30 young
variables exhibit Hα emission, near-IR (NIR)/mid-IR (MIR)
excess or both and are candidate members of the cluster. Out of 62
variables, 41 are periodic variables, with a rotation rate ranging
from 0.2-7d. The period distribution exhibits a median period at
∼1d, as in many young clusters (e.g. NGC 2264, ONC, etc.), but
it follows a unimodal distribution, unlike others that have
bimodality, with slow rotators peaking at ∼6-8d. To investigate
the rotation-disc and variability-disc connection, we derived the NIR
excess from Δ(I-K) and the MIR excess from Spitzer [3.6]-[4.5]um
data. No conclusive evidence of slow rotation with the presence of
discs around stars and fast rotation for discless stars is obtained
from our periodic variables. A clear increasing trend of the
variability amplitude with IR excess is found for all variables.
Description:
RI photometric and I-band time-series observations of the cluster
NGC 2282 were carried out over 25 epochs during 2013 October
15-2016 February 18 using two different Indian telescopes. We
performed photometric observations using the 2048x2048 Andor CCD
camera on the 1.3-m Devasthal Fast Optical Telescope (DFOT), located
in Nainital, India.
We also carried out photometric observations using the Himalaya Faint
Object Spectrograph Camera (HFOSC) on the 2-m Himalayan Chandra
Telescope (HCT), located at Hanle, India.
Objects:
-----------------------------------------
RA (2000) DE Designation(s)
-----------------------------------------
06 46 51 +01 18.9 NGC 2282 = IC 2172
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 180 62 Catalogue of the identified variable stars
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See also:
J/MNRAS/454/3597 : NGC 2282 BVI Ha observations (Dutta+, 2015)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- ID Identification number, [DMJ2015] NNNN in Simbad
6- 15 F10.6 deg RAdeg Right ascension (J2000)
17- 24 F8.6 deg DEdeg Declinaition (J2000)
27- 32 F6.3 mag Bmag ?=99.999 B magnitude
34- 39 F6.3 mag e_Bmag ?=99.999 rms uncertainty on Bmag
41- 46 F6.3 mag Vmag ?=99.999 V magnitude
48- 53 F6.3 mag e_Vmag ?=99.999 rms uncertainty on Vmag
56- 61 F6.3 mag Rmag ?=99.999 R magnitude
63- 68 F6.3 mag e_Rmag ?=99.999 rms uncertainty on Rmag
70- 75 F6.3 mag Imag ?=99.999 I magnitude
77- 82 F6.3 mag e_Imag ?=99.999 rms uncertainty on Imag
84- 89 F6.3 mag Jmag ?=99.999 J magnitude
91- 96 F6.3 mag e_Jmag ?=99.999 rms uncertainty on Jmag
98-103 F6.3 mag Hmag ?=99.999 H magnitude
105-110 F6.3 mag e_Hmag ?=99.999 rms uncertainty on Hmag
112-117 F6.3 mag Kmag ?=99.999 K magnitude
119-124 F6.3 mag e_Kmag ?=99.999 rms uncertainty on Kmag
126-131 F6.3 mag [3.6] ?=99.999 Spitzer/IRAC 3.6um magnitude
133-138 F6.3 mag e_[3.6] ?=99.999 rms uncertainty on [3.6]
140-145 F6.3 mag [4.5] ?=99.999 Spitzer/IRAC 4.5um magnitude
147-152 F6.3 mag e_[4.5] ?=99.999 rms uncertainty on [4.5]
154-159 F6.3 mag W1mag ?=99.999 Wise W1 (3.4um) magnitude
161-166 F6.3 mag e_W1mag ?=99.999 rms uncertainty on W1mag
168-173 F6.3 mag W2mag ?=99.999 Wise W2 (4.6um) magnitude
175-180 F6.3 mag e_W2mag ?=99.999 rms uncertainty on W2mag
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History:
From electronic version of the journal
References:
Dutta et al., Paper I 2015MNRAS.454.3597D 2015MNRAS.454.3597D, Cat. J/MNRAS/454/3597
(End) Patricia Vannier [CDS] 27-Apr-2021