J/AJ/159/262 OGLE/KMTnet VI bands photometry of OGLE-2019-BLG-0551 (Mroz+, 2020)
A free-floating or wide-orbit planet in the microlensing event
OGLE-2019-BLG-0551.
Mroz P., Poleski R., Han C., Udalski A., Gould A., Szymanski M.K.,
Soszynski I., Pietrukowicz P., Kozlowski S., Skowron J., Ulaczyk K.,
Gromadzki M., Rybicki K., Iwanek P., Wrona M., Albrow M.D., Chung S.-J.,
Hwang K.-H., Ryu Y.-H., Jung Y.K., Shin I.-G., Shvartzvald Y., Yee J.C.,
Zang W., Cha S.-M., Kim D.-J., Kim H.-W., Kim S.-L., Lee C.-U., Lee D.-J.,
Lee Y., Park B.-G., Pogge R.W.
<Astron. J., 159, 262 (2020)>
=2020AJ....159..262M 2020AJ....159..262M
ADC_Keywords: Gravitational lensing; Exoplanets; Photometry, VRI
Keywords: Gravitational microlensing ; Free floating planets ;
Gravitational microlensing exoplanet detection ; Finite-
source photometric effect
Abstract:
High-cadence observations of the Galactic bulge by the microlensing
surveys led to the discovery of a handful of extremely short-timescale
microlensing events that can be attributed to free-floating or
wide-orbit planets. Here, we report the discovery of another strong
free-floating planet candidate, which was found from the analysis of
the gravitational microlensing event OGLE-2019-BLG-0551. The light
curve of the event is characterized by a very short duration (≲3days)
and a very small amplitude (≲0.1mag). From modeling of the light
curve, we find that the Einstein timescale, tE=0.381±0.017day,
is much shorter, and the angular Einstein radius,
θE=4.35±0.34µmas, is much smaller than those of typical
lensing events produced by stellar-mass lenses (tE∼20days,
θE∼0.3mas), indicating that the lens is very likely to be a
planetary-mass object. We conduct an extensive search for possible
signatures of a companion star in the light curve of the event,
finding no significant evidence for the putative host star. For the
first time, we also demonstrate that the angular Einstein radius of
the lens does not depend on blending in the low-magnification events
with strong finite source effects.
Description:
The magnification of the source flux induced by lensing was first
found by the Optical Gravitational Lensing Experiment (OGLE) Early
Warning System on 2019-April-27 (HJD'=HJD-2450000∼8600). Two days
later (HJD'∼8602), the event was independently identified by the Korea
Microlensing Telescope Network (KMTNet) and it was designated as
KMT-2019-BLG-0519 in the KMTNet event list.
The OGLE survey is conducted utilizing the 1.3m Warsaw telescope
located at Las Campanas Observatory in Chile. The telescope is
equipped with a mosaic camera that consists of 32 2kx4k detectors,
yielding a 1.4deg2 field of view with a single exposure. The KMTNet
survey uses three identical 1.6m telescopes that are globally
distributed at the Siding Spring Observatory in Australia (KMTA),
Cerro Tololo Interamerican Observatory in Chile (KMTC), and the South
African Astronomical Observatory in South Africa (KMTS). Each of the
KMTNet telescopes is equipped with a camera consisting of four 9kx9k
chips, yielding 4deg2 field of view. For both surveys, images are
mainly taken in the I band and a small subset of images is obtained in
the V band for the source color measurements.
Objects:
-----------------------------------------------------------------
RA (2000) DE Designation(s)
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17 59 28.74 -28 50 25.8 OGLE-2019-BLG-0551 = EWS 2019-BLG-551
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
figure1.dat 35 11022 Light curve of OGLE-2019-BLG-0551
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See also:
J/AcA/52/217 : OGLE II. VI photometry of Galactic Bulge (Udalski+, 2002)
J/ApJ/636/240 : OGLE II microlensing parameters (Sumi+, 2006)
J/ApJS/216/12 : OGLE-III Galactic bulge microlensing events (Wyrzykowski+,2015)
J/AJ/154/210 : 2015 high-cadence Spitzer microlensing events (Zhu+, 2017)
J/AJ/155/186 : The KMTNet/K2-C9 (Kepler) Data Release (Kim+, 2018)
J/ApJS/244/29 : Microlensing events toward the Galactic bulge (Mroz+, 2019)
J/AJ/159/98 : I-band LC of KMT-2016-BLG-1836 (Yang+, 2020)
Byte-to-byte description of file: figure1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 F13.5 d HJD [2458521/2458788] Heliocentric Julian Date
15- 21 F7.4 mag mag [13.48/13.76] Apparent magnitude
23- 28 F6.4 mag e_mag [0.003/0.03] Uncertainty in mag
30- 35 A6 --- Obs Observatory (1)
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Note (1): Observatories as follows:
KMTA03 = 1.6m telescope at the Siding Spring Observatory in Australia
(2026 occurrences)
KMTA43 = 1.6m telescope at the Siding Spring Observatory in Australia
(1981 occurrences)
KMTC43 = 1.6m telescope at Cerro Tololo Interamerican Observatory in Chile
(1988 occurrences)
KMTS03 = 1.6m telescope at the South African Astronomical Observatory in
South Africa (2132 occurrences)
KMTS43 = 1.6m telescope at the South African Astronomical Observatory in
South Africa (2107 occurrences)
OGLE = Optical Gravitational Lensing Experiment (788 occurrences)
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 27-Jul-2020