Astronomy and Astrophysics – Astronomy
Scientific paper
May 2002
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2002aas...200.7420b&link_type=abstract
American Astronomical Society, 200th AAS Meeting, #74.20; Bulletin of the American Astronomical Society, Vol. 34, p.773
Astronomy and Astrophysics
Astronomy
Scientific paper
We discuss the flux and polarization signals obtained from the microlensing of stars with extended circumstellar envelopes by a single point-mass lens. We find that stars with extended envelopes will show a high level of variable polarisation (up to 10%), even if they are spherically symmetric. Since the stellar envelopes most likely to be lensed are produced by red giant winds, we include the effects of a central cavity (representing the dust condensation radius) within the scattering envelope. In this paper we show that, even if the event is not a photospheric transit, the combination of photometric and polarimetric light curves determines the angular Einstein radius of the lens, θ E, the lens impact parameter, θ 0, and the lens proper motion, μ L (both direction and magnitude). Basically, the level of polarization at flux maximum determines the lens impact parameter, the flux amplification gives the Einstein radius, and the variation of the polarisation position angle determines both the magnitude and direction of the lens proper motion. Since the lens proper motion can place kinematic constraints on the distance to the lens, we conclude polarization measurements of the microlensing event can help constrain the allowable range of lens masses.
Bjorkman Jon E.
Ignace Richard
Simmons John F. L.
No associations
LandOfFree
Gravitational Microlensing of Circumstellar Envelopes does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Gravitational Microlensing of Circumstellar Envelopes, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Gravitational Microlensing of Circumstellar Envelopes will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1720749