OGLE-2013-BLG-1761Lb: A Massive Planet around an M/K Dwarf

Abstract

We report the discovery and the analysis of the planetary microlensing event, OGLE-2013-BLG-1761. There are some degenerate solutions in this event because the planetary anomaly is only sparsely sampled. However,the detailed lightcurve analysis ruled out all stellar binary models and shows the lens to be a planetary system. There is the so-called close/wide degeneracy in the solutions with the planet/host mass ratio of q∼(7.0±2.0)×10 −3 and q∼(8.1±2.6)×10−3 with the projected separation in Einstein radius units of s=0.95 (close) and s=1.18 (wide), respectively. The microlens parallax effect is not detected, but the finite source effect is detected. Our Bayesian analysis indicates that the lens system is located = . The preference of the large lens distance in the Bayesian analysis is due to the relatively large observed source star radius. The distance and other physical parameters may be constrained by the future high-resolution imaging by large groundtelescopes orHST. If the estimated lens distance is correct, thenthis planet provides another sample for testing the claimed deficit of planets in the Galactic bulge.-

Keck Observations Confirm a Super-Jupiter Planet Orbiting M Dwarf OGLE-2005-BLG-071L

“…Another candidate super-Jupiter mass planet in the sample orbiting a low mass star is MOA-2012-BLG-006 (Poleski et al 2017), but a mass measurement for this event would be quite difficult, because of its bright giant source star. In addition to these events in the sample, the following events are candidates for super-Jupiter planets orbiting low-mass stars: MOA-2010-BLG-73, OGLE-2013-BLG-0102, OGLE-2013-BLG-1761, OGLE-2015-BLG-0954, MOA-2016-BLG-227, OGLE-2016-BLG-0263, KMT-2016-BLG-1397, and KMT-2017-BLG-1038(Street et al 2013Jung et al 2015;Hirao et al 2017;Shin et al 2016;Bennett et al 2017;Koshimoto et al 2017b;Zang et al 2018;Shin et al 2019). Perhaps the most interesting candidate is OGLE-2018-BLG-1011 (Han et al 2019), which has two super-Jupiter planets with mass ratios of 0.015 and 0.0095 orbiting a star with an estimated mass of ∼ 0.2M .…”

A Planetary Microlensing Event with an Unusually Red Source Star: MOA-2011-BLG-291

“…However the CMD for this event does not show a pronounced elongation of the red clump along the reddening vector, at (A I , E(V − I)) = (1.604, 1.368). Events at even lower galactic latitudes, like OGLE-2013-BLG-1761 at b = −1.48 (Hirao et al 2017) and OGLE-2015-BLG-1670 at b = −1.12 ) are more likely to exhibit this excess extinction effect, and in fact, the source for OGLE-2013-BLG-1761 is also anomalously red. For the one microlens planet discovered with infrared data only, UKIRT-2017-BLG-001Lb , at b = −0.33, the extinction of the source star is almost certainly larger than that of the red clump stars, but this source is likely to be in the background disk.…”

“…For three of these events Mróz et al 2017b;Shvartzvald et al 2018), there is no color measurement, but 4 of the remaining 13 low latitude events have anomalously red sources. Besides MOA-2011-BLG-291, these are OGLE-2013-BLG-0341 , OGLE-2013-BLG-1761(Hirao et al 2017, and OGLE-2014-BLG-0676 (Rattenbury et al 2017). Three more have colors that are marginally redder than the main sequence or subgiant branch (Mróz et al 2017a;Hwang et al 2018;.…”

OGLE-2016-BLG-0168 Binary Microlensing Event: Prediction and Confirmation of the Microlens Parallax Effect from Space-based Observations

“…Second, the subtle deviations in the light curve due to microlens parallax effects can be confused with photometric systematics that can lead to a false positive detection or inaccurate measurement of the annual microlens parallax. For example, systematics in MOA data, which are taken under difficult conditions, occasionally lead to spurious detections of the microlens parallax that are contradicted by other data sets (e.g., Hirao et al 2017). Therefore, it is important to verify, where possible, that the annual microlens parallax effect has been accurately measured.…”