J/AJ/170/75 LCs of KMT-2022-BLG-0086 with 2L2s & 3L1S models (Chung+, 2025)
KMT-2022-BLG-0086: Another binary-lens binary-source microlensing event.
Chung S.-J., Hwang K.-H., Yee J.C., Gould A., Bond I.A., Yang H.,
(the Leading Authors), Albrow M.D., Jung Y.K., Han C., Ryu Y.-H.,
Shin I.-G., Shvartzvald Y., Zang W., Cha S.-M., Kim D.-J., Kim S.-L.,
Lee C.-U., Lee D.-J., Lee Y., Park B.-G., Pogge R.W.,
(the Kmtnet Collaboration), Abe F., Bennett D.P., Bhattacharya A.,
Fukui A., Hamada R., Hirao Y., Ishitani Silva S., Koshimoto N.,
Miyazaki S., Muraki Y., Nagai T., Nunota K., Olmschenk G., Ranc C.,
Rattenbury N.J., Satoh Y., Sumi T., Suzuki D., Terry S.K., Tristram P.J.,
Vandorou A., Yama H., (the Moa Collaboration)
<Astron. J. 170, 75 (2025)>
=2025AJ....170...75C 2025AJ....170...75C
ADC_Keywords: Gravitational lensing; Photometry; Optical; Models;
Stars, double and multiple
Keywords: Gravitational microlensing
Abstract:
We present the analysis of a microlensing event KMT-2022-BLG-0086 of
which the overall light curve is not described by a binary-lens
single-source (2L1S) model, which suggests the existence of an extra
lens or an extra source. We found that the event is best explained by
the binary-lens binary-source (2L2S) model, but the 2L2S model is only
favored over the triple-lens single-source (3L1S) model by
Δχ2∼9. Although the event has noticeable anomalies
around the peak of the light curve, they are not enough covered to
constrain the angular Einstein radius θE, thus we only measure
the minimum angular Einstein radius θE,min. From the Bayesian
analysis, it is found that that the binary lens system is a binary
star with masses of
(m1,m2)=(0.46+0.35-0.25M☉,0.75+0.67-0.55M☉) at
a distance of DL=5.87+1.21-1.79kpc, while the triple lens system
is a brown dwarf or a massive giant planet in a low-mass binary-star
system with masses of (m1,m2,m3)=
(0.43+0.41-0.35M☉,0.056+0.055-0.047M☉,
20.84+20.20-17.04M☉), at a distance of
DL=4.06+1.39-3.28kpc, indicating a disk lens system. The 2L2S
model yields the relative lens-source proper motion of
µrel≥4.6mas/yr that is consistent with the Bayesian result,
whereas the 3L1S model yields µrel≥18.9mas/yr, which is more
than three times larger than that of a typical disk object of ∼6mas/yr
and thus is not consistent with the Bayesian result. This suggests
that the event is likely caused by the binary-lens binary-source
model.
Description:
The event was first discovered by the Korea Microlensing Telescope
Network (KMTNet). KMTNet uses three identical 1.6m telescopes with
4deg2 field of view (FOV) cameras that are globally distributed at
the Cerro Tololo Inter-American Observatory in Chile (KMTC), the South
African Astronomical Observatory (KMTA), and the Siding Spring
Observatory (KMTS) in Australia. The KMTNet observations were carried
out in the I and V bands. The event lies in the KMT subprime field
BLG15 with a cadence of Γ=1/hr.
The Microlensing Observations in Astrophysics (MOA) also independently
found this event and it was designated as MOA-2022-BLG-130. MOA uses a
1.8m telescope with 2.2deg2 FOV at Mt. John Observatory in New
Zealand. The MOA observations were carried out in the MOA-Red band
RMOA that corresponds to the sum of the Cousins R and I bands.
Objects:
-------------------------------------------------------------------
RA (2000) DE Designation(s)
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17 33 57.67 -27 06 02.5 KMT-2022-BLG-0086 = KMT-2022-BLG-0086
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File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
fig4.dat 48 12 List of files and plots from Figure 4 (added by CDS)
lc/* . 12 Light curves files in MRT format
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See also:
J/A+A/466/157 : Bulge Microlensing Events (Soto+, 2007)
J/A+A/533/A134 : Abundances of microlensed stars in the Bulge (Bensby+, 2011)
J/ApJ/778/150 : Microlensing events toward the Bulge from MOA-II (Sumi+, 2013)
J/ApJ/827/139 : Microlensing opt. depth & event rates from MOA-II (Sumi+, 2016)
J/A+A/617/A135 : 20 years of photometric microlensing (Mustill+, 2018)
J/AcA/68/183 : Predicted Microlensing Events for 21st Century (Bramich+, 2018)
J/ApJS/244/29 : Microlensing events toward the Galactic bulge (Mroz+, 2019)
J/A+A/640/A83 : Mass determination using microlensing by Gaia (Klueter+, 2020)
J/MNRAS/498/L6 : Gaia DR2 predictions of microlensing events (McGill+, 2020)
J/AJ/161/293 : LCs of OGLE-2018-BLG-0567 and OGLE-2018-BLG-0962 (Jung+, 2021)
J/AJ/163/176 : Prediction of microlensing events with Gaia EDR3 (Kluter+, 2022)
J/A+A/674/A23 : Gaia DR3 Microlensing events (Wyrzykowski+, 2023)
J/AJ/165/83 : KMTNet light curve for 4 microlensing planets (Ryu+, 2023)
J/AJ/169/288 : LCs of microlensing events revealing planets (Han+, 2025)
Byte-by-byte Description of file: fig4.dat
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Bytes Format Units Label Explanations
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1- 6 A6 --- Tel Telescope (1)
8 A1 --- Filter Filter
10- 13 A4 --- Model Model (2)
15- 19 A5 --- f_Model Solution of the 2L2S model (wide or close)
21- 45 A25 --- File Link to the light curve file in MRT format
47- 48 A2 --- LC Associated light curve with link to interactive
plot
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Note (1): Telescope as follows:
KMTA15 = The 1.6m telescope from the Korea Microlensing Telescope Network
(KMTNet) at the South African Astronomical Observatory (KMTA)
KMTC15 = The 1.6m telescope from the Korea Microlensing Telescope Network
(KMTNet) at the Cerro Tololo Inter-American Observatory in Chile
(KMTC)
KMTS15 = The 1.6m telescope from the Korea Microlensing Telescope Network
(KMTNet) at the Siding Spring Observatory (KMTS) in Australia
MOA = The 1.8m telescope from the Microlensing Observations in
Astrophysics (MOA) at Mt. John Observatory in New Zealand
Note (2): Models as follows:
2L2S = Binary-lens binary-source (2L2S) model (See Section 3.2)
3L1S = Triple-lens single-source (3L1S) model (See Section 3.3)
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History:
From electronic version of the journal
License: CC-BY-4.0
(End) Prepared by [AAS], Robin Leichtnam [CDS] 26-May-2026