Rosanne Di Stefano, James Matthews, Sebastien Lepine
The first predicted mesolensing event is likely to occur during the winter or
spring of 2011/2012. The lens is the nearby, low-mass high-proper-motion star
VB 10, and the source a distant field star much bluer than VB 10 and 1.5
magnitudes dimmer in B band. If VB 10 has planets, they could produce lensing
signatures that enhance the detectability of the stellar-lens event and/or
produce distinct planet-lens signatures. Here, we study the lensing signatures
associated with planets orbiting nearby high-proper-motion stars to provide a
guide for observers for this event and future predicted ones. We illustrate our
case by considering hypothetical planets orbiting VB 10 with separations
ranging from 2 R_{sun} to tens of AU. We find the following. (1) Wide-orbit
planets can be detected for all distances of closest approach between the
foreground and background stars, potentially producing independent events long
before and/or after the closest approach. (2) Close-orbit planets can be
detected for intermediate distances of closest approach (less than about 50 mas
for VB 10), producing quasiperiodic signatures that may occur days or weeks
before and after the stellar-lens event. (3) Planets in the so-called 'zone for
resonant lensing' can significantly increase the magnification when the
distance of closest approach is small (less than about 20 mas for VB 10),
making the stellar-lens event easier to detect while simultaneously providing
evidence for planets. We show that an observing plan in which VB 10 is targeted
several times per night at each of several longitudes will either detect
planets, or else place weak limits on possible parameters. We expect VB 10 to
be the first of a continuing line of predicted events. An observing program for
this event can pave the way for future programs and discoveries. This is
discussed in more detail in Paper II.
View original:
http://arxiv.org/abs/1202.5316
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