J/AJ/165/175 Light curve follow up of MOA-2020-BLG-208L (Olmschenk+, 2023)
MOA-2020-BLG-208Lb; Cool Sub-Saturn-mass Planet within Predicted Desert.
Olmschenk G., Bennett D.P., Bond I.A., Zang W., Jung Y.K., Yee J.C.,
Bachelet E., Abe F., Barry R.K., Bhattacharya A., Fujii H., Fukui A.,
Hirao Y., Silva S.I., Itow Y., Kirikawa R., Kondo I., Koshimoto N.,
Matsubara Y., Matsumoto S., Miyazaki S., Munford B., Muraki Y.,
Okamura A., Ranc C., Rattenbury N.J., Satoh Y., Sumi T., Suzuki D.,
Toda T., Tristram P.J., Vandorou A., Yama H., Albrow M.D., Cha S.-M.,
Chung S.-J., Gould A., Han C., Hwang K.-H., Kim D.-J., Kim H.-W.,
Kim S.-L., Lee C.-U., Lee D.-J., Lee Y., Park B.-G., Pogge R.W.,
Ryu Y.-H., Shin I.-G., Shvartzvald Y., Christie G., Cooper T.,
Drummond J., Green J., Hennerley S., McCormick J., Monard L.A.G.,
Natusch T., Porritt I., Tan T.-G., Mao S., Maoz D., Penny M.T., Zhu W.,
Bozza V., Cassan A., Dominik M., Hundertmark M., Jaimes R.F.,
Kruszynska K., Rybicki K.A., Street R.A., Tsapras Y., Wambsganss J.,
Wyrzykowski L., Zielinski P., Rau G., Leading authors,
The MOA Collaboration, The KMTNet Collaboration,
The MicroFUN Collaboration, The MAP Follow-Up Collaboration,
The OMEGA Collaboration
<Astron. J., 165, 175 (2023)>
=2023AJ....165..175O 2023AJ....165..175O
ADC_Keywords: Gravitational lensing; Exoplanets; Photometry, VRI
Keywords: Gravitational microlensing ; Gravitational microlensing exoplanet
detection ; Binary lens microlensing
Abstract:
We analyze the MOA-2020-BLG-208 gravitational microlensing event and
present the discovery and characterization of a new planet,
MOA-2020-BLG-208Lb, with an estimated sub-Saturn mass. With a mass
ratio q=3.17-0.26+0.28e-4, the planet lies near the peak of the
mass-ratio function derived by the MOA collaboration and near the edge
of expected sample sensitivity. For these estimates we provide results
using two mass-law priors: one assuming that all stars have an equal
planet-hosting probability, and the other assuming that planets are
more likely to orbit around more massive stars. In the first scenario,
we estimate that the lens system is likely to be a planet of mass
Mp=46-24+42M⊕ and a host star of mass
Ms=0.43-0.23+0.39M☉, located at a distance
DL=7.49-1.13+0.99kpc. For the second scenario, we estimate
Mp=69-34+37M⊕, Ms=0.66-0.32+0.35M☉, and
DL=7.81-0.93+0.93kpc. The planet has a projected separation as a
fraction of the Einstein ring radius s=1.3807-0.0018+0.0018. As a
cool sub-Saturn-mass planet, this planet adds to a growing collection
of evidence for revised planetary formation models.
Description:
The MOA observations were performed using the purpose-built 1.8m
wide-field MOA telescope located at Mount John Observatory, New
Zealand, and were taken at a 15minutes cadence with the MOA-Red
filter. Additional observations were made by MOA in the visual band
using the MOA-V filter.
Others follow-up observations were taken using the 1.0m telescope of
the Las Cumbres Observatory global network located at the South
African Astronomical Observatory, South Africa (LCOS), the 0.4m
telescopes at Auckland Observatory and Possum Observatory, the 0.36m
telescopes at Kumeu Observatory, Klein Karoo Observatory, Turitea
Observatory and Farm Cove Observatory, and the 0.3 mPerth Exoplanet
Survey Telescope in Australia.
In addition, this event was observed by the Korea Microlensing
Telescope Network (KMTNet) with two 1.6m telescopes located at the
Siding Spring Observatory, Australia and the South African
Astronomical Observatory, South Africa.
The Observing Microlensing Events of the Galaxy Automatically project
(OMEGA) observed the event with 1.0m telescopes located at the South
African Astronomical Observatory, South Africa, using the Las Cumbres
Observatory network of robotic telescopes.
Objects:
---------------------------------------------------------------
RA (ICRS) DE Designation(s)
---------------------------------------------------------------
17 53 43.80 -32 35 21.5 MOA-2020-BLG-208 = MOA 2020-BLG-208
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
fig1.dat 33 2870 The MOA-2020-BLG-208 event light curve
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See also:
J/other/Nat/481.167 : 2002-2007 PLANET microlensing events (Assan+, 2012)
J/AJ/158/13 : First 300 stars observed by the GPIES (Nielsen+, 2019)
J/AJ/161/54 : VRI photometry of MOA 2009-BLG-319 (Terry+, 2021)
J/AJ/164/118 : VRI light curve MOA 2020-BLG-135 (Ishitani Silva+, 2022)
Byte-by-byte Description of file: fig1.dat
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Bytes Format Units Label Explanations
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1- 11 F11.6 d HJD [9000/9140] Heliocentric Julian Date; HJD-2450000
13- 19 F7.4 mag mag [0.91/43.1] Magnitude
21- 26 F6.4 mag e_mag [0.008/4] Uncertainty in mag
28- 33 A6 --- Inst Instrument identifier (1)
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Note (1): Instruments as follows:
auck = Auckland Observatory 0.4m telescopes;
fco = Farm Cove Observatory;
kko = Klein Karro Observatory;
kmtI = Korea Microlensing Telescope Network 1.6m telescope I filter;
kum = Kumeu Observatory 0.36m telescopes;
moa2r = Mount John Observatory 1.8m wide-field MOA telescope Red filter;
moa2v = Mount John Observatory 1.8m wide-field MOA telescope V filter;
omegag = Observing Microlensing Events of the Galaxy Automatically SDSS
g filter;
omegai = Observing Microlensing Events of the Galaxy Automatically SDSS i
filter
pest = Perth Exoplanet Survey 0.3m Telescope;
pos = Possum Observatory;
lcos = South African Astronomical Observatory;
tur = Turitea Observatory.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 08-Sep-2023