Published June 2020 | Version Accepted Version + Published
Journal Article Open

OGLE-2018-BLG-0677Lb: A Super-Earth Near the Galactic Bulge

Abstract

We report the analysis of the microlensing event OGLE-2018-BLG-0677. A small feature in the light curve of the event leads to the discovery that the lens is a star–planet system. Although there are two degenerate solutions that could not be distinguished for this event, both lead to a similar planet-host mass ratio. We perform a Bayesian analysis based on a Galactic model to obtain the properties of the system and find that the planet corresponds to a super-Earth/sub-Neptune with a mass of M_(planet) = 3.96^(+5.88)_(−2.66) M⊕. The host star has a mass of M_(host) = 0.12^(+0.14)_(−0.08) M⊙. The projected separation for the inner and outer solutions are 0.63^(+0.20)_(−0.17) au and 0.72^(+0.23)_(−0.19) au respectively. At Δχ² = χ² (1L1S) –χ ²(2L1S) = 46, this is by far the lowest Δχ² for any securely detected microlensing planet to date, a feature that is closely connected to the fact that it is detected primarily via a "dip" rather than a "bump."

Additional Information

© 2020 The American Astronomical Society. Received 2020 March 4; revised 2020 April 6; accepted 2020 April 10; published 2020 May 7. A.H.M. and M.D.A. are supported by the Marsden Fund under contract UOC1602. The OGLE project has received funding from the National Science Centre, Poland, grant MAESTRO 2014/14/A/ST9/00121 to A.U. W.Z. acknowledges support by the National Science Foundation of China (grant No. 11821303 and 11761131004) A.G. received support from the European Research Council under the European Unions Seventh Framework Programme (FP 7) ERC grant Agreement no. [321035] This research has made use of the KMTNet system operated by the Korea Astronomy and Space Science Institute (KASI) and the data were obtained at three host sites of CTIO in Chile, SAAO in South Africa, and SSO in Australia. Work by C.H. was supported by the grants (2017R1A4A1015178 and 2019R1A2C2085965) of National Research Foundation of Korea.

Attached Files

Published - Herrera-Martín_2020_AJ_159_256.pdf

Accepted Version - 2003.02983.pdf

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2003.02983.pdf

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Additional details

Identifiers

Eprint ID
103097
Resolver ID
CaltechAUTHORS:20200511-100530014

Related works

Funding

Marsden Fund
UOC1602
National Science Centre (Poland)
MAESTRO 2014/14/A/ST9/00121
National Natural Science Foundation of China
11821303
National Natural Science Foundation of China
11761131004
European Research Council (ERC)
321035
National Research Foundation of Korea
2017R1A4A1015178
National Research Foundation of Korea
2019R1A2C2085965

Dates

Created
2020-05-11
Created from EPrint's datestamp field
Updated
2021-11-16
Created from EPrint's last_modified field