Variability of young stellar objects in the star-forming region Pelican Nebula. (arXiv:1906.00256v1 [astro-ph.SR])
<a href="http://arxiv.org/find/astro-ph/1/au:+Bhardwaj_A/0/1/0/all/0/1">A. Bhardwaj</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Panwar_N/0/1/0/all/0/1">N. Panwar</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Herczeg_G/0/1/0/all/0/1">G. J. Herczeg</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Chen_W/0/1/0/all/0/1">W. P. Chen</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Singh_H/0/1/0/all/0/1">H. P. Singh</a>
We observed a field of $16’times 16’$ in the star-forming region Pelican
Nebula (IC 5070) at $BVRI$ wavelengths for 90 nights spread over one year in
2012-2013. More than 250 epochs in $VRI$-bands are used to identify and
classify variables up to $Vsim 21$~mag. We present a catalogue of optical
time-series photometry with periods, mean-magnitudes and classifications for 95
variable stars including 67 pre-main-sequence variables towards star-forming
region IC 5070. The pre-main-sequence variables are further classified as
candidate classical T Tauri and weak-line T Tauri stars based on their light
curve variations and the locations on the color-color and color-magnitude
diagrams using optical and infrared data together with Gaia DR2 astrometry.
Classical T Tauri stars display variability amplitudes up to three times the
maximum fluctuation in disk-free weak-line T Tauri stars, which show strong
periodic variations. Short-term variability is missed in our photometry within
single nights. Several classical T Tauri stars display long-lasting ($geq 10$
days) single or multiple fading and brightening events up to a couple of
magnitudes at optical wavelengths. The typical mass and age of the
pre-main-sequence variables from the isochrone-fitting and spectral energy
distributions are estimated to be $le 1~M_odot$ and $sim 2$ Myr,
respectively. We do not find any correlation between the optical amplitudes or
periods with the physical parameters (mass and age) of pre-main-sequence stars.
We observed a field of $16’times 16’$ in the star-forming region Pelican
Nebula (IC 5070) at $BVRI$ wavelengths for 90 nights spread over one year in
2012-2013. More than 250 epochs in $VRI$-bands are used to identify and
classify variables up to $Vsim 21$~mag. We present a catalogue of optical
time-series photometry with periods, mean-magnitudes and classifications for 95
variable stars including 67 pre-main-sequence variables towards star-forming
region IC 5070. The pre-main-sequence variables are further classified as
candidate classical T Tauri and weak-line T Tauri stars based on their light
curve variations and the locations on the color-color and color-magnitude
diagrams using optical and infrared data together with Gaia DR2 astrometry.
Classical T Tauri stars display variability amplitudes up to three times the
maximum fluctuation in disk-free weak-line T Tauri stars, which show strong
periodic variations. Short-term variability is missed in our photometry within
single nights. Several classical T Tauri stars display long-lasting ($geq 10$
days) single or multiple fading and brightening events up to a couple of
magnitudes at optical wavelengths. The typical mass and age of the
pre-main-sequence variables from the isochrone-fitting and spectral energy
distributions are estimated to be $le 1~M_odot$ and $sim 2$ Myr,
respectively. We do not find any correlation between the optical amplitudes or
periods with the physical parameters (mass and age) of pre-main-sequence stars.
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