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Related papers: Microlensing, Brown Dwarfs and GAIA

200 papers

Gravitational microlensing may detect dark stellar remnants - black holes or neutron stars - even if they are isolated. However, it is challenging to estimate masses of isolated dark stellar remnants using solely photometric data for…

Solar and Stellar Astrophysics · Physics 2021-09-15 P. Mroz , L. Wyrzykowski

Microlensing is the only known direct method to measure the masses of stars that lack visible companions. In terms of microlensing observables, the mass is given by M=(c^2/4G)\tilde r_E \theta_E and so requires the measurement of both the…

We report on the observations, analysis and interpretation of the microlensing event MOA-2019- BLG-008. The observed anomaly in the photometric light curve is best described through a binary lens model. In this model, the source did not…

It has been shown by Paczy\'nski that gravitational microlensing is a useful method to detect brown dwarfs in the dark halo of our galaxy. At present several experiments are carried out to monitor several million stars in the Large…

Astrophysics · Physics 2008-02-03 Philippe Jetzer

In order to understand the nature of the lenses that generate microlensing events, one would like to measure their mass, distance, and velocity. Unfortunately, current microlensing experiments measure only one parameter of the events, the…

Astrophysics · Physics 2009-10-28 B. Scott Gaudi , Andrew Gould

Extrasolar planet searches targeting very low-mass stars and brown dwarfs are hampered by intrinsic or instrumental limitations. Time series of astrometric measurements with precisions better than one milli-arcsecond can yield new evidence…

Solar and Stellar Astrophysics · Physics 2014-05-08 J. Sahlmann , P. F. Lazorenko , D. Segransan , E. L. Martin , M. Mayor , D. Queloz , S. Udry

We show that a wide-field Kepler-like satellite in Solar orbit could obtain microlens parallaxes for several thousand events per year that are identified from the ground, yielding masses and distances for several dozen planetary events.…

Earth and Planetary Astrophysics · Physics 2015-06-17 Andrew Gould , Keith Horne

Microlensing is a powerful and unique technique to probe isolated objects in the Galaxy. To study the characteristics of these interesting objects based on the microlensing method, measurement of the microlens parallax is required to…

Free-floating planets are the remnants of violent dynamical rearrangements of planetary systems. It is possible that even our own solar system ejected a large planet early in its evolution. WFIRST will have the ability to detect…

Results from gravitational microlensing suggested the existence of a large population of free-floating planetary mass objects. The main conclusion from this work was partly based on constraints from a direct imaging survey. This survey…

Astrophysics of Galaxies · Physics 2015-06-04 Sascha P. Quanz , David Lafreniere , Michael R. Meyer , Maddalena M. Reggiani , Esther Buenzli

I propose a radical revision in the search strategy for Massive Compact Objects (Machos) toward the Galactic bulge: monitor the entire $\sim 300$ square deg of the bulge and tune the search primarily to microlensing events of bright…

Astrophysics · Physics 2009-10-22 Andrew Gould

The mass of single neutron stars (NSs) can be measured using astrometric microlensing events. In such events, the center-of-light motion of a star lensed by a NS will deviate from the expected non-lensed motion and this deviation can be…

High Energy Astrophysical Phenomena · Physics 2018-10-31 Eran O. Ofek

KOI-3278 is a self-lensing stellar binary consisting of a white-dwarf secondary orbiting a Sun-like primary star. Kruse and Agol (2014) noticed small periodic brightenings every 88.18 days in the Kepler photometry and interpreted these as…

GAIA will provide observations of some multiple asteroid and dwarf systems. These observations are a way to determine and improve the quantification of dynamical parameters, such as the masses and the gravity fields, in these multiple…

Earth and Planetary Astrophysics · Physics 2012-04-27 L. Beauvalet , V. Lainey , J. -E. Arlot , D. Bancelin , R. P. Binzel , F. Marchis

Gaia will not observe 50000 brown dwarfs, but about 100 times less. However, these <~ 500 brown dwarfs will be benchmarks for many substellar topics. It is possible to identify them in advance and make the list public to all astronomers…

Solar and Stellar Astrophysics · Physics 2014-08-12 J. A. Caballero

A measurement by microlensing of the planetary mass function of planets with masses ranging from 5M_E to 10M_J and orbital radii from 0.5 to 10 AU was reported recently. A strategy for extending the mass range down to (1-3)M_E is proposed…

The gravitational pull of an unseen companion to a luminous star is well-known to cause deviations to the parallax and proper motion of a star. In a previous paper in this series, we argue that the astrometric mission Gaia can identify…

High Energy Astrophysical Phenomena · Physics 2023-03-01 Jeff J. Andrews

In the context of the ESA M5 (medium mission) call we proposed a new satellite mission, Theia, based on relative astrometry and extreme precision to study the motion of very faint objects in the Universe. Theia is primarily designed to…

Instrumentation and Methods for Astrophysics · Physics 2017-07-06 The Theia Collaboration , Celine Boehm , Alberto Krone-Martins , Antonio Amorim , Guillem Anglada-Escude , Alexis Brandeker , Frederic Courbin , Torsten Ensslin , Antonio Falcao , Katherine Freese , Berry Holl , Lucas Labadie , Alain Leger , Fabien Malbet , Gary Mamon , Barbara McArthur , Alcione Mora , Michael Shao , Alessandro Sozzetti , Douglas Spolyar , Eva Villaver , Conrado Albertus , Stefano Bertone , Herve Bouy , Michael Boylan-Kolchin , Anthony Brown , Warren Brown , Vitor Cardoso , Laurent Chemin , Riccardo Claudi , Alexandre C. M. Correia , Mariateresa Crosta , Antoine Crouzier , Francis-Yan Cyr-Racine , Mario Damasso , Antonio da Silva , Melvyn Davies , Payel Das , Pratika Dayal , Miguel de Val-Borro , Antonaldo Diaferio , Adrienne Erickcek , Malcolm Fairbairn , Morgane Fortin , Malcolm Fridlund , Paulo Garcia , Oleg Gnedin , Ariel Goobar , Paulo Gordo , Renaud Goullioud , Nigel Hambly , Nathan Hara , David Hobbs , Erik Hog , Andrew Holland , Rodrigo Ibata , Carme Jordi , Sergei Klioner , Sergei Kopeikin , Thomas Lacroix , Jacques Laskar , Christophe Le Poncin-Lafitte , Xavier Luri , Subhabrata Majumdar , Valeri Makarov , Richard Massey , Bertrand Mennesson , Daniel Michalik , Andre Moitinho de Almeida , Ana Mourao , Leonidas Moustakas , Neil Murray , Matthew Muterspaugh , Micaela Oertel , Luisa Ostorero , Angeles Perez-Garcia , Imants Platais , Jordi Portell i de Mora , Andreas Quirrenbach , Lisa Randall , Justin Read , Eniko Regos , Barnes Rory , Krzysztof Rybicki , Pat Scott , Jean Schneider , Jakub Scholtz , Arnaud Siebert , Ismael Tereno , John Tomsick , Wesley Traub , Monica Valluri , Matt Walker , Nicholas Walton , Laura Watkins , Glenn White , Dafydd Wyn Evans , Lukasz Wyrzykowski , Rosemary Wyse

Time delays between the multiple images of strongly lensed Type Ia supernovae (gl\sneia) have the potential to deliver precise cosmological constraints, but the effects of microlensing on the measurement have not been studied in detail.…

Cosmology and Nongalactic Astrophysics · Physics 2018-03-14 Daniel A. Goldstein , Peter E. Nugent , Daniel N. Kasen , Thomas E. Collett