Астронет: Астрономическая картинка дня Мерцающая звезда укажет на состав Галактики http://variable-stars.ru/db/msg/1163461/eng |
Credit & Copyright: The MACHO Collaboration
Explanation:
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.
Authors & editors:
Robert Nemiroff
(MTU) &
Jerry Bonnell
(USRA)
NASA Web Site Statements, Warnings,
and Disclaimers
NASA Official: Jay Norris.
Specific
rights apply.
A service of:
LHEA at
NASA /
GSFC
& Michigan Tech. U.