Measuring microlensing parallax via simultaneous observations from Chinese Space Station Telescope and Roman Telescope

Abstract

Simultaneous observations from two spatially well-separated telescopes can lead to the measurements of the microlensing parallax parameter, an important quantity toward the determinations of the lens mass. The separation between Earth and Sun-Earth L2 point, $\sim 0.01$ AU, is ideal for parallax measurements of short and ultra-short ($\sim$1\,hr to 10\,days) microlensing events, which are candidates of free-floating planet (FFP) events. In this work, we study the potential of doing so in the context of two proposed space-based missions, the Chinese Space Station Telescope (CSST) in a Leo orbit and the Nancy Grace Roman Space Telescope (\emph{Roman}) at L2. We show that the joint observations of the two can directly measure the microlensing parallax of nearly all FFP events with timescales $t_{\mathrm{E}}\lesssim$ 10\,days as well as planetary (and stellar binary) events that show caustic crossing features. The potential of using CSST alone in measuring microlensing parallax is also discussed.

accepted to Research in Astronomy and Astrophysics (RAA)

References in corpus (8)

• Wide-Field InfrarRed Survey Telescope-Astrophysics Focused Telescope Assets WFIRST-AFTA 2015 Report
• No large population of unbound or wide-orbit Jupiter-mass planets
• The Exoplanet Mass-Ratio Function from the MOA-II Survey: Discovery of a Break and Likely Peak at a Neptune Mass
• First Space-Based Microlens Parallax Measurement: Spitzer Observations of OGLE-2005-SMC-001
• Predictions of the Nancy Grace Roman Space Telescope Galactic Exoplanet Survey II: Free-Floating Planet Detection Rates
• Predictions for Microlensing Planetary Events from Core Accretion Theory
• Spitzer as Microlens Parallax Satellite: Mass and Distance Measurements of Binary Lens System OGLE-2014-BLG-1050L
• An Isolated Microlens Observed from K2, Spitzer and Earth

Cited by in corpus (9)

• Limits on planetary-mass primordial black holes from the OGLE high-cadence survey of the Magellanic Clouds
• Systematic KMTNet Planetary Anomaly Search, Paper VII: Complete Sample of $q<10^{-4}$ Planets from the First Four-Year Survey
• How Rare are TESS Free-Floating Planets?
• Exoplanet Occurrence Rates from Microlensing Surveys
• A differentiable binary microlensing model using adaptive contour integration method
• Simulations of Triple Microlensing Events I: Detectability of a scaled Sun-Jupiter-Saturn System
• Identification of stellar-mass black hole binaries and the validity of linear orbital motion approximation in microlensing
• Detecting Exomoons in Free-Floating-Planet Events from Space-based Microlensing Surveys
• KMT-2025-BLG-1314 and KMT-2025-BLG-1392: two microlensing planetary/brown-dwarf candidates analyzed with differentiable code