WFIRST Planet Masses from Microlens Parallax

Abstract

I present a method using only a few ground-based observations of magnified microlensing events to routinely measure the parallaxes of WFIRST events if WFIRST is in an L2 orbit. This could be achieved for all events with Amax > 30 using target-ofopportunity observations of select WFIRST events, or with a complementary, ground-based survey of the WFIRST field, which can push beyond this magnification limit. When combined with a measurement of the angular size of the Einstein ring, which is almost always measured in planetary events, these parallax measurements will routinely give measurements of the lens masses and hence, the absolute masses of the planets. They can also lead to mass measurements for dark, isolated objects such as brown dwarfs, free-floating planets, and stellar remnants if the size of the Einstein ring is measured.

11 pages, 2 figures. Replaced 10/10/13 to reflect the version published in ApJL

References in corpus (5)

• First Space-Based Microlens Parallax Measurement: Spitzer Observations of OGLE-2005-SMC-001
• Microlens Terrestrial Parallax Mass Measurements: A Rare Probe of Isolated Brown Dwarfs and Free-Floating Planets
• Gas Giants in Hot Water: Inhibiting Giant Planet Formation and Planet Habitability in Dense Star Clusters Through Cosmic Time
• Geosynchronous Microlens Parallaxes
• Space based microlensing planet searches

Cited by in corpus (15)

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• A Neptune-mass Free-floating Planet Candidate Discovered by Microlensing Surveys
• Campaign 9 of the $K2$ Mission: Observational Parameters, Scientific Drivers, and Community Involvement for a Simultaneous Space- and Ground-based Microlensing Survey
• Solar System Physics for Exoplanet Research
• Constraining the Frequency of Free-Floating Planets from a Synthesis of Microlensing, Radial Velocity, and Direct Imaging Survey Results
• OGLE-2015-BLG-1482L: the first isolated low-mass microlens in the Galactic bulge
• Euclid-Roman joint microlensing survey: early mass measurement, free floating planets and exomoons
• Microlensing constraints on the mass of single stars from HST astrometric measurements
• Masses for Free-Floating Planets and Dwarf Planets
• An Isolated Microlens Observed from K2, Spitzer and Earth
• Microlensing by Kuiper, Oort, and Free-Floating Planets
• Measuring microlensing parallax via simultaneous observations from Chinese Space Station Telescope and Roman Telescope
• Microlensing Parallax for Observers in Heliocentric Motion
• Never bet against Einstein
• The impact of the free-floating planet (FFP) mass function on the event rate for the accurate microlensing parallax determination: application to Euclid and Roman parallax observation