Details

Autor(en) / Beteiligte

• Kim, Hyoun-Woo
• Hwang, Kyu-Ha
• Gould, Andrew
• Yee, Jennifer C.
• Ryu, Yoon-Hyun
• Albrow, Michael D.
• Chung, Sun-Ju
• Han, Cheongho
• Kil Jung, Youn
• Lee, Chung-Uk
• Shin, In-Gu
• Shvartzvald, Yossi
• Zang, Weicheng
• Cha, Sang-Mok
• Kim, Dong-Jin
• Kim, Seung-Lee
• Lee, Dong-Joo
• Lee, Yongseok
• Park, Byeong-Gon
• Pogge, Richard W.

Titel

KMT-2019-BLG-2073: Fourth Free-floating Planet Candidate with θ E < 10 μas

Ist Teil von

• The Astronomical journal, 2021-07, Vol.162 (1), p.15

Ort / Verlag

Madison: The American Astronomical Society

Erscheinungsjahr

2021

Link zum Volltext

Quelle

EZB-FREE-00999 freely available EZB journals

Beschreibungen/Notizen

• Abstract We analyze the very short Einstein timescale ( t E ≃ 7 hr) event KMT-2019-BLG-2073. Making use of the pronounced finite-source effects generated by the clump giant source, we measure the Einstein radius θ E ≃ 4.8 μ as and so infer a mass M = 59 M ⊕ ( π rel / 16 μ as ) − 1 , where π rel is the lens-source relative parallax. We find no significant evidence for a host of this planetary-mass object, though one could be present at sufficiently wide separation. If so, it would be detectable after about 10 yr. This is the fourth isolated microlens with a measured Einstein radius θ E < 10 μ as, which we argue is a useful threshold for a “likely free-floating planet (FFP)” candidate. We outline a new approach to constructing a homogeneous sample of giant-star finite-source/point-lens (FSPL) events, within which the subsample of FFP candidates can be statistically analyzed. We illustrate this approach using 2019 KMTNet data and show that there appears to be a large θ E gap between the two FFP candidates and the 11 other FSPL events. We argue that such sharp features are more identifiable in a sample selected on θ E compared to the traditional approach of identifying candidates based on short t E .