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We evaluate gravitational lensing as a technique for the detection of extrasolar moons. Since 2004 gravitational microlensing has been successfully applied as a detection method for extrasolar planets. In principle, the method is sensitive…

Earth and Planetary Astrophysics · Physics 2014-11-20 Christine Liebig , Joachim Wambsganss

Episodically accreting black holes are thought to produce flares when a chunk of particles is accelerated to high velocity near the black hole horizon. This also seems to be the case of Sagittarius A* in the Galactic Center, where the…

Astrophysics · Physics 2009-07-17 V. Karas , M. Dovciak , A. Eckart , L. Meyer

Extended source effects can be seen in gravitational lensing events when sources cross critical lines. Those events probe the stellar intensity profile and could be used to measure limb darkening coefficients to test stellar model…

Instrumentation and Methods for Astrophysics · Physics 2019-08-14 Hans J. Witt , F. Atrio-Barandela

A new window to observing individual stars and other small sources at cosmological distances was opened recently, with the detection of several caustic-crossing events in galaxy cluster fields. Many more such events are expected soon from…

Instrumentation and Methods for Astrophysics · Physics 2022-08-15 Ashish Kumar Meena , Ofir Arad , Adi Zitrin

Weak gravitational lensing from large-scale structure enhances and reduces the fluxes from extragalactic point sources with an rms amplitude of order 15%. In cosmic microwave background (CMB) experiments, sources exceeding some flux…

Astrophysics · Physics 2015-06-24 Max Tegmark , Jens Villumsen

The density of stars and MACHOs in the universe could theoretically be determined or limited by simultaneous measurements of compact sources by well separated observers. A gravitational lens effect would be expected to create a slight…

Astrophysics · Physics 2009-10-30 Robert J. Nemiroff

Although many methods of detecting extra-solar planets have been proposed and successful implementation of some of these methods enabled a rapidly increasing number of exoplanet detections, little has been discussed about the method of…

Astrophysics · Physics 2009-11-07 Cheongho Han , Wonyong Han

We consider small-scale spheroidal clusters of weakly interacting massive particles in our Galaxy as non-compact gravitational microlenses and predict the appearance of caustics in the plane of a lensed source. The crossing of these…

Astrophysics · Physics 2010-04-30 M. B. Bogdanov , A. M. Cherepashchuk

A close-in giant planetary (CGP) system has a net polarization signal whose value varies depending on the orbital phase of the planet. This polarization signal is either caused by the stellar occultation or by reflected starlight from the…

Earth and Planetary Astrophysics · Physics 2017-04-07 Sedighe Sajadian , Markus Hundertmark

In recent years free-loating planets (FFPs) have drawn a great interest among astrophysicists. Gravitational microlensing is a unique and exclusive method for their investigation which may allow obtaining precious information about their…

Earth and Planetary Astrophysics · Physics 2015-09-23 Lindita Hamolli , Mimoza Hafizi , Francesco De Paolis , Achille A. Nucita

We describe the results and outline the methods used in a search for microlensing events affecting stars in the outer bulge and inner disk of M31, due both to masses in M31 and the Galaxy. These observations, from 1994 and 1995 on the…

Astrophysics · Physics 2007-05-23 Arlin P. S. Crotts

The detection of microlensing events from stars in the Large Magellanic Cloud and in the Galactic bulge raise important constraints on the distribution of dark matter and on galactic structure, although some events may be due to a new type…

Astrophysics · Physics 2020-11-25 David Valls-Gabaud

During some gravitational lensing events, the lens transits the face of the star. This causes a shift in the apparent radial velocity of the star which is proportional to its rotation speed. It also changes the magnification relative to…

Astrophysics · Physics 2009-10-28 Andrew Gould

We investigate the possibilities that pulsars act as the lens in gravitational microlensing events towards the galactic bulge or a spiral arm. Our estimation is based on expectant survey and observations of FAST (Five hundred meter Aperture…

High Energy Astrophysical Phenomena · Physics 2015-05-14 S. Dai , R. X. Xu , A. Esamdin

We qualitatively study the effects of gravitational microlensing on our view of unresolved extragalactic star formation regions. Using a general gravitational microlensing configuration, we perform a number of simulations that reveal that…

Astrophysics · Physics 2009-11-11 Rodrigo Gil-Merino , Geraint F. Lewis

We study the prospects for detecting gamma-rays from point sources of Dark Matter annihilation with the space satellite GLAST. We simulate the instrument response to the gamma-ray spectrum arising from the annihilation of common Dark Matter…

The fraction of quasar's and gamma-ray burst (GRB) afterglows that vary due to microlensing by the stellar populations of intervening elliptical/S0 galaxies is computed by combining the joint distribution of effective microlensing…

Astrophysics · Physics 2009-11-07 J. S. B. Wyithe , E. L. Turner

If the dark halo of our galaxy is made of compact objects as massive as M = 10^6 solar masses, their detection by means of ordinary microlensing searches would take a very long time as the characteristic time scale of such a lensing event,…

Astrophysics · Physics 2007-05-23 Bohdan Paczynski

Traditional approaches to measuring the stellar mass function (MF) are fundamentally limited because objects are detected based on their luminosity, not their mass. These methods are thereby restricted to luminous and relatively nearby…

Astrophysics · Physics 2009-10-28 Andrew Gould

The MACHO collaboration has been carrying out Difference Image Analysis (DIA) since 1996 with the aim of increasing the sensitivity to the detection of gravitational microlensing. This is a preliminary report on the application of DIA to…

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