Gaia21blx: Complete resolution of a binary microlensing event in the Galactic disk
arXiv:2404.05078 · doi:10.1051/0004-6361/202347807
Abstract
Context. Gravitational microlensing is a method that is used to discover planet-hosting systems at distances of several kiloparsec in the Galactic disk and bulge. We present the analysis of a microlensing event reported by the Gaia photometric alert team that might have a bright lens. Aims. In order to infer the mass and distance to the lensing system, the parallax measurement at the position of Gaia21blx was used. In this particular case, the source and the lens have comparable magnitudes and we cannot attribute the parallax measured by Gaia to the lens or source alone. Methods. Since the blending flux is important, we assumed that the Gaia parallax is the flux-weighted average of the parallaxes of the lens and source. Combining this assumption with the information from the microlensing models and the finite source effects we were able to resolve all degeneracies and thus obtained the mass, distance, luminosities and projected kinematics of the binary lens and the source. Results. According to the best model, the lens is a binary system at kpc from Earth. It is composed of a G star with and a K star with . The source is likely to be an F subgiant star at kpc with a mass of . Both lenses and the source follow the kinematics of the thin-disk population. We also discuss alternative models, that are disfavored by the data or by prior expectations, however.
11 pages, 6 figures. Accepted for publication in A&A
References in corpus (64)
- The Gaia mission
- Evolutionary tracks and isochrones for low- and intermediate-mass stars: from 0.15 to 7 M_sun, and from Z=0.0004 to 0.03
- A Survey of Stellar Families: Multiplicity of Solar-Type Stars
- Las Cumbres Observatory Global Telescope Network
- Gaia Early Data Release 3: Photometric content and validation
- Trigonometric Parallaxes Of High-Mass Star Forming Regions: Our View Of The Milky Way
- ESPRESSO@VLT -- On-sky performance and first results
- Real-Time Difference Imaging Analysis of MOA Galactic Bulge Observations During 2000
- Gaia broad band photometry
- The Use of High Magnification Microlensing Events in Discovering Extra-solar Planets
- OGLE 2003-BLG-235/MOA 2003-BLG-53: A planetary microlensing event
- A Natural Formalism for Microlensing
- Three-dimensional mapping of the local interstellar medium with composite data
- The VST Photometric Halpha Survey of the Southern Galactic Plane and Bulge (VPHAS+)
- Resolution of the MACHO-LMC-5 Puzzle: The Jerk-Parallax Microlens Degeneracy
- MOA-2011-BLG-293Lb: A test of pure survey microlensing planet detections
- Microlensing optical depth towards the Galactic bulge from MOA observations during 2000 with Difference Image Analysis
- A New Algorithm For Difference Image Analysis
- Binary microlensing event OGLE-2009-BLG-020 gives a verifiable mass, distance and orbit predictions
- Gaia Data Release 3: External calibration of BP/RP low-resolution spectroscopic data
- First microlens mass measurement: PLANET photometry of EROS BLG-2000-5
- IAC-Star: a Code for Synthetic Color-Magnitude Diagram Computation
- The 1995 Pilot Campaign of PLANET: Searching for Microlensing Anomalies through Precise, Rapid, Round-the-Clock Monitoring
- The Extreme Microlensing Event OGLE-2007-BLG-224: Terrestrial Parallax Observation of a Thick-Disk Brown Dwarf
- Stellar Diameters and Temperatures IV. Predicting Stellar Angular Diameters
- Black Hole, Neutron Star and White Dwarf Candidates from Microlensing with OGLE-III
- An isolated mass gap black hole or neutron star detected with astrometric microlensing
- Microlensing with advanced contour integration algorithm: Green's theorem to third order, error control, optimal sampling and limb darkening
- Pathway to the Galactic Distribution of Planets: Combined Spitzer and Ground-Based Microlens Parallax Measurements of 21 Single-Lens Events
- The First Circumbinary Planet Found by Microlensing: OGLE-2007-BLG-349L(AB)c
- Astrophysical Applications of Gravitational Microlensing
- Difference Image Analysis: Extension to a Spatially Varying Photometric Scale Factor and Other Considerations
- The Optical Gravitational Lensing Experiment. Is Interstellar Extinction Toward the Galactic Center Anomalous?
- RoboNet-II: Follow-up observations of microlensing events with a robotic network of telescopes
- VBBinaryLensing: a public package for microlensing light curve computation
- On the Milky Way spiral arms from open clusters in Gaia EDR3
- OGLE-2012-BLG-0563Lb: a Saturn-mass Planet around an M Dwarf with the Mass Constrained by Subaru AO imaging
- Astrometric Microlensing with the GAIA satellite
- Detecting stars, galaxies, and asteroids with Gaia
- The Gaia-ESO survey: impact of extra-mixing on C- and N-abundances of giant stars
- Population synthesis to constrain Galactic and Stellar Physics- I- Determining age and mass of thin-disc red-giant stars
- The Two-Colour EMCCD Instrument for the Danish 1.54m Telescope and SONG
- Systematic errors as a source of mass discrepancy in black hole microlensing event OGLE-2011-BLG-0462
- On the accuracy of mass measurement for microlensing black holes as seen by Gaia and OGLE
- MOA-2007-BLG-197: Exploring the brown dwarf desert
- Microlensing Searches for Exoplanets
- Spitzer Microlens Measurement of a Massive Remnant in a Well-Separated Binary
- Gaia Data Release 3: Microlensing Events from All Over the Sky
- Full orbital solution for the binary system in the northern Galactic disc microlensing event Gaia16aye
- A Predicted Astrometric Microlensing Event by a Nearby White Dwarf
- OGLE-2008-BLG-510: first automated real-time detection of a weak microlensing anomaly - brown dwarf or stellar binary?
- The Empirical Mass-Luminosity Relation for Low Mass Stars
- A possible binary system of a stellar remnant in the high magnification gravitational microlensing event OGLE-2007-BLG-514
- Single-lens mass measurement in the high-magnification microlensing event Gaia19bld located in the Galactic disc
- Sloan/Johnson-Cousins/2MASS Color Transformations for Cool-Stars
- The complete catalogue of light curves in equal-mass binary microlensing
- A public code for astrometric microlensing with contour integration
- Lens parameters for Gaia18cbf -- a long gravitational microlensing event in the Galactic plane
- Is there a nearby microlensing stellar remnant hiding in Gaia DR3 astrometry?
- Prediction of Astrometric-Microlensing Events from Gaia eDR3 Proper Motions
- A spectroscopic follow-up for Gaia19bld
- Theoretical Mass-Luminosity Relations in Gaia G-Band
- Precision measurement of a brown dwarf mass in a binary system in the microlensing event OGLE-2019-BLG-0033/MOA-2019-BLG-035
- MOA-2020-BLG-208Lb: Cool Sub-Saturn Planet Within Predicted Desert