OGLE-2015-BLG-1670Lb: A Cold Neptune beyond the Snow Line in the Provisional WFIRST Microlensing Survey Field
Year: 2019
Type: article
Abstract: We present the analysis of the microlensing event OGLE-2015-BLG-1670, detected in a high-extinction field very close to the Galactic plane. Due to the dust extinction along the line of sight, this event was too faint to be detected before it reached the peak of magnification. The microlensing light-curve models indicate a high-magnification event with a maximum of A max ≳ 200, very sensitive to planetary deviations. An anomaly in the light curve has been densely observed by the microlensing surveys MOA, KMTNet, and OGLE. From the light-curve modeling, we find a planetary anomaly characterized by a planet-to-host mass ratio, q = 1.00 − 0.16 + 0.18 × 10 − 4 , at the peak recently identified in the mass-ratio function of microlensing planets. Thus, this event is interesting to include in future statistical studies about planet demography. We have explored the possible degeneracies and find two competing planetary models resulting from the s ↔ 1 / s degeneracy. However, because the projected separation is very close to s = 1, the physical implications for the planet for the two solutions are quite similar, except for the value of s. By combining the light-curve parameters with a Galactic model, we have estimated the planet mass M 2 = 17.9 − 8.8 + 9.6 M ⊕ and the lens distance D L = 6.7 − 1.3 + 1.0 kpc , corresponding to a Neptune-mass planet close to the Galactic bulge. Such events with a low absolute latitude ( ∣ b ∣ ≈ 1 .° 1 ) are subject to both high extinction and more uncertain source distances, two factors that may affect the mass measurements in the provisional Wide Field Infrared Survey Telescope fields. More events are needed to investigate the potential trade-off between the higher lensing rate and the difficulty in measuring masses in these low-latitude fields.
Source: The Astronomical Journal
Authors: Clément Ranc, David P. Bennett, Yuki Hirao, Andrzej Udalski, Cheongho Han, Ian A. Bond, Jennifer C. Yee, and, Michael D. Albrow, Sun-Ju Chung, Andrew Gould, Kyu-Ha Hwang, Youn-Kil Jung, Yoon-Hyun Ryu, In-Gu Shin, Yossi Shvartzvald, Weicheng Zang, Wei Zhu, Sang-Mok Cha, Dong-Jin Kim, Hyoun-Woo Kim, Seung-Lee Kim, Chung-Uk Lee, Dong-Joo Lee, Yong-Seok Lee, Byeong-Gon Park, Richard W. Pogge, Fumio Abe, Richard K. Barry, Aparna Bhattacharya, Martin Donachie, Akihiko Fukui, Yoshitaka Itow, Kohei Kawasaki, Iona Kondo, Naoki Koshimoto, Man Cheung Alex Li, Yutaka Matsubara, Shota Miyazaki, Yasushi Muraki, Masayuki Nagakane, Nicholas J. Rattenbury, Haruno Suematsu, Denis J. Sullivan, Takahiro Sumi, Daisuke Suzuki, Paul J. Tristram, Atsunori Yonehara, Radosław Poleski, Przemek Mróz, Jan Skowron, Michał K. Szymański, Igor Soszyński, Szymon Kozłowski, Paweł Pietrukowicz, Krzysztof Ulaczyk
Institutions: Goddard Space Flight Center, University of Maryland, College Park, The University of Osaka, University of Warsaw, Chungbuk National University, Massey University, Center for Astrophysics Harvard & Smithsonian, University of Canterbury, Korea Astronomy and Space Science Institute, Korea University of Science and Technology, Max Planck Institute for Astronomy, The Ohio State University, California Institute of Technology, Infrared Processing and Analysis Center, Tsinghua University, Kyung Hee University, Institute for Space-Earth Environmental Research, Nagoya University, Nagoya University, University of Auckland, National Institutes of Natural Sciences, Instituto de Astrofísica de Canarias, National Astronomical Observatory of Japan, The University of Tokyo, Victoria University of Wellington, Japan Aerospace Exploration Agency, Institute of Space and Astronautical Science, Kyoto Sangyo University, University of Warwick
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
Awards: 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., Microlensing Survey for Exoplanets beyond the Snow Line, IGF::OT::IGF CRESST IITHE GODDARD CENTER FOR RESEARCH AND EXPLORATION IN SPACE SCIENCE AND TECHNOLOGY (CRESST) II WILL CARRY OUT OBSERVATIONAL EXPERIMENTAL AND THEORETICAL RESEARCH IN SUPPORT OF NASA STRATEGIC SCIENCE MISSION OBJECTIVES RELATING TO:A.THE SOLAR SYSTEM STARS GALAXIES AND THE UNIVERSE AT LARGE;B.THE INFORMATIONAL AND COMPUTATIONAL SCIENCES RELATED TO THE UNIQUE NEEDS OF DATA SYSTEMS REQUIRED TO INTERPRET DATA FROM THE SPACE SCIENCES; ANDC.THE DEVELOPMENT OF THE TECHNOLOGY REQUIRED TO ACHIEVE THESE SCIENTIFIC CHALLENGES.THIS COOPERATIVE AGREEMENT WILL ALLOW FOR SUBSTANTIAL PROGRAMMATIC INVOLVEMENT IN THE FORM OF COLLABORATION BETWEEN GSFC AND THE CRESST II AS WELL AS JOINT DEVELOPMENT OF RESEARCH OBJECTIVES.THE GOAL IS TO ESTABLISH A FOCUSED PARTNERSHIP THAT:A.BRINGS TOGETHER GSFC AND EXTERNAL SCIENTISTS TO IMPLEMENT THE NASA STRATEGIC GOAL IN SPACE SCIENCE;B.BUILDS ON THE CAPABILITIES AND STRENGTHS OF PARTICIPATING ORGANIZATION IN SPACE SCIENCE;C.PROVIDES ORGANIZATION AND STAFFING FLEXIBILITY TO ADAPT TO EVOLVING RESEARCH PROGRAM NEEDS;D.INCREASES THE INVOLVEMENT OF MINORITY AND WOMEN SCIENTISTS IN SPACE SCIENCE RESEARCH; ANDE.FACILITATES ACCESS TO STUDENT TALENT AND PROVIDES OPPORTUNITIES FOR THEIR PARTICIPATION IN NASA PROGRAMS.A BROAD AND VIGOROUS SPACE RESEARCH PROGRAM IN NASA IS VITAL FOR THE ADVANCEMENT OF KNOWLEDGE. SCIENTISTS AT NASA IN COLLABORATION WITH OUTSIDE SCIENTISTS PLAY A KEY ROLE IN CONCEIVING NEW SPACE MISSIONS PROVIDING MISSION REQUIREMENTS AND ACHIEVING RESEARCH OBJECTIVES AIMED AT UNDERSTANDING THE ORIGINS STRUCTURE AND EVOLUTION OF SYSTEMS IN THE UNIVERSE AND EXPLORING THE SOLAR SYSTEM.THE CRESST II WILL FOCUS PRIMARILY ON SCIENTIFIC RESEARCH. IT IS EXPECTED TO STRENGTHEN COOPERATIVE RELATIONSHIPS BETWEEN THE RECIPIENT AND GOVERNMENT SCIENTISTS IN THE GODDARD SCIENCES AND EXPLORATION DIRECTORATE (SED) AND WILL PROVIDE A VEHICLE TO INCREASE THE INVOLVEMENT OF THE EXTERNAL SCIENCE COMMUNITY IN THE PURSUIT OF NASA GOALS.THE CRESST II WILL CONDUCT RESEARCH COLLABORATIVELY WITH ORGANIZATIONAL ELEMENTS WITHIN THE GODDARD SED (CODE 600). RESEARCH MAY INVOLVE ANALYSIS OF DATA FROM OPERATING AND PAST MISSIONS AND MODELING AND DESIGN OF MISSIONS PLANNED OR UNDER DEVELOPMENT. FUTURE RESEARCH ACTIVITIES WILL EVOLVE AS A FUNCTION OF PRIORITIES BUDGETS FUNDING OPPORTUNITIES AND SUCCESS OF PROPOSAL SUBMISSIONS., G4211331249, Search for extrasolar planets with microlensing, G6996030003, 世界初の近赤外線による重力マイクロレンズ法を用いた系外惑星探査, Search for cold exoplanets and free-floating planets by near infrared gravitational microlensing observation, G7558095811
OpenAlex ID: W2944995500