Astrophysics (index)about


(massive compact halo object, massive astrophysical compact halo object)
(proposed astronomical objects comprising dark matter)

MACHO (for massive astrophysical compact halo object aka massive compact halo object) is a proposed dark matter element consisting of an astronomical object of considerable size/mass (e.g., planet-sized or larger), but producing too little electromagnetic radiation to be observed, such as brown dwarfs, black holes and/or field planetary mass objects. Searches for them include surveys of occultations and gravitational microlensing. Finding enough to statistically explain the kinematics of galaxies would be evidence for MACHOs, but this hasn't been accomplished.

An alternative idea is that dark matter consists of some exotic subatomic particle, the term being used for one being a WIMP.

(dark matter,object type)

Referenced by:
dark matter
gravitational lensing
MACHO Project