OGLE-2016-BLG-1195Lb: A Sub-Neptune Beyond the Snow Line of an M-dwarf Confirmed by Keck Adaptive Optics
Year: 2025
Type: article
Abstract: We present the analysis of high-resolution follow-up observations of OGLE-2016-BLG-1195 using Laser Guide Star Adaptive Optics with Keck, seven years after the event’s peak. We resolve the lens, measuring its flux and the relative source-lens proper motion, thus finding the system to be a M p = 10.08 ± 1.18M ⊕ planet orbiting an M-dwarf, M L = 0.62 ± 0.05M ⊙, beyond the snow line, with a projected separation of r ⊥ = 2.24 ± 0.21 au at D L = 7.45 ± 0.55 kpc. Our results are consistent with the discovery paper, which reports values with 1σ uncertainties based on a single mass–distance constraint from finite source effects. However, both the discovery paper and our follow-up results disagree with the analysis of a different group that also present the planetary signal detection. The latter utilizes Spitzer photometry to measure a parallax signal claiming the system is an Earth-mass planet orbiting an ultracool dwarf. Their parallax signal though is improbable since it suggests a lens star in the disk moving perpendicular to or counter to the Galactic disk rotation. Moreover, microlensing parallaxes can be impacted by systematic errors in the photometry. Therefore, we reanalyze the Spitzer photometry using a pixel level decorrelation model to detrend detector systematics. We find that we cannot confidently recover the same detrended light curve that is likely dominated by systematic errors in the photometric data. The results of this paper act as a cautionary tale that a careful understanding of detector systematics and how they influence astrophysical constraints is crucial.
Source: The Astronomical Journal
Authors: Aikaterini Vandorou, Lisa Dang, David P. Bennett, Naoki Koshimoto, Sean K. Terry, Andrzej Udalski, Jean-Philippe Beaulieu, Christophe Alard, Aparna Bhattacharya, Joshua W. Blackman, Ian A. Bond, Tarik Bouchoutrouch-Ku, Andrew A. Cole, Nicolas B. Cowan, Jean-Baptiste Marquette, Clément Ranc, Natalia E. Rektsini, Sylvain Cetre, Jim Lyke, Eduardo Marin, Peter Wizinowich
Institutions: Goddard Space Flight Center, University of Maryland, College Park, McGill University, Université de Montréal, The University of Osaka, University of California, Berkeley, University of Warsaw, Centre National de la Recherche Scientifique, University of Tasmania, Institut d'Astrophysique de Paris, Sorbonne Université, Massey University, Laboratoire d'Astrophysique de Bordeaux, Heidelberg University, W.M. Keck Observatory
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $4,499
Funders: National Science Foundation, National Aeronautics and Space Administration, W. M. Keck Foundation, Alexander von Humboldt-Stiftung, California Institute of Technology, NASA Exoplanet Science Institute, Australian Government, University of Tasmania, Agence Nationale de la Recherche, Nuclear Safety and Security Commission, McGill Space Institute, Natural Sciences and Engineering Research Council of Canada
Awards: MRI: Development of a Fast and Flexible Adaptive Optics Controller, Astrophysics enabled by Keck All Sky Precision Adaptive Optics, IN DECEMBER 2015 WE WERE INFORMED OF THE WFIRST SCIENCE INVESTIGATION TEAM SELECTIONS AND OF THE FUNDING FOR THE WIRST SCIENCE INVESTIGATION TEAMS. UNFORTUNATELY THE FUNDING FOR THE WFIRST EXOPLANET MICROLENSING PROGRAM WAS NOT SUFFICIENT TO DEVELOP ALL THE TOOLS NEEDED TO EXECUTE THIS PROGRAM. BECAUSE OF THIS THE PI SUBMITTED A REQUEST TO THE NASA PROGRAM OFFICER DR. DOMINIC BENFORD TO CHANGE THE FOCUS OF THIS WFIRST PREPARATORY SCIENCE GRANT AND DR. BENFORD APPROVED THIS REQUEST. THE NEW FOCUS INCLUDES THE DEVELOPMENT OF THE WFIRST EXOPLANET MICROLENSING SURVEY PHOTOMETRY/ASTROMETRY PIPELINE ALGORITHMS AND THE DEVELOPMENT OF ADVANCED LIGHT CURVE MODELING AND DATA ANALYSIS METHODS. IT ALSO INCLUDES THE STUDY OF MICROLENSING EVENTS LOCATED IN THE CANDIDATE WFIRST EXOPLANET MICROLENSING SURVEY FIELDS TO DETERMINE IF NEW DIFFICULTIES MIGHT ARISE WITH THE WFIRST EXOPLANET MASS MEASUREMENT METHODS DUE TO THE LOW LATITUDES OF THE WFIRST MICROLENSING FIELDS., G3676852958, G4656594441, G5477955166, demographics of planets close to their birth place & their occurrence in the disk and the bar of our Galaxy., G7796512131
OpenAlex ID: W4410517639