Open AccessChromaticity of gravitational microlensing events
Author(s) -
Han Cheongho,
Park SeongHong,
Jeong JangHae
Publication year - 2000
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2000.03485.x
Subject(s) - gravitational microlensing , physics , light curve , chromaticity , astrophysics , distortion (music) , gravitational lens , lens (geology) , event (particle physics) , proper motion , optics , astronomy , stars , galaxy , amplifier , optoelectronics , cmos , redshift
In this paper, we investigate the colour changes of gravitational microlensing events caused by the two different mechanisms of differential amplification for a limb‐darkened extended source and blending. From this investigation, we find that the colour changes of limb‐darkened extended source events (colour curves) have dramatically different characteristics depending on whether the lens transits the source star or not. We show that for a source transit event, the lens proper motion can be determined by simply measuring the turning time of the colour curve instead of fitting the overall colour or light curves. We also find that even for a very small fraction of blended light, the colour changes induced by blending are equivalent to those induced by limb darkening, causing serious distortion in the observed colour curve. Therefore, to obtain useful information about the lens and source star from the colour curve of an event, it will be essential to correct for blending. We discuss various methods of blending correction.