APOD.pl: astronomiczne zdjęcie dnia

Codziennie nowy obraz lub zdjęcie naszego fascynującego Wszechświata
wraz z krótkim objaśnieniem napisanym przez zawodowego astronoma.
Zobacz więcej!

24 czerwca 1998

Sparkling Star May Indicate Galactic Composition
Źródło: The MACHO Collaboration

Opis: 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.

Jutro: Strange Galaxy


< | Archiwum | Lista tematyczna | Szukaj | Kalendarz | Słownik | Edukacja | O APOD | >

Autorzy i wydawcy: Robert Nemiroff (MTU) & Jerry Bonnell (USRA)
NASA Technical Rep.: Jay Norris. Specific rights apply.
A service of: LHEA at NASA/ GSFC
&: Michigan Tech. U.