Sparkling Star May Indicate Galactic Composition
Credit:
The MACHO Collaboration
If a star in this photograph twinkled slightly,
would anyone notice? Would anyone care? Astronomers with the
MACHO Collaboration noticed one such twinkle
just last week, and many members of the
astronomical community now care.
The specific type of sparkling of the
SMC star in the above cross-hairs
clearly indicated a multiple-star microlensing event was in progress.
Microlensing is a rare phenomena where
gravity itself deflects light so prominently that
background sources might appear to have
many images and appear
many times their normal brightness.
Study of the
precise
details of the latter part of this
microlensing
event might reveal the mass and distance to the lenses.
Were these lenses in the outer reaches of our
Galactic halo, this would add evidence to some
controversial indications that a good fraction of the normally
unseen matter in
our Galaxy
is composed of lenses only slightly less massive than
our Sun.