Binary system telescope or binoculars. Eclipsing binaries are where the objects' orbits are at an angle that when one passes in front of the other it causes an eclipse, as seen from Earth. Astrometric binaries are objects that seem to move around nothing as their companion object cannot be identified, it can only be inferred. The companion object may not be bright enough or may be hidden in the glare from the primary object. A related classification though not a binary system is Optical binary which refers to objects that are so close together in the sky that they appear to be
Transfer DNA binary system Transfer DNA binary system A transfer DNA (T-DNA) binary system is a pair of plasmids consisting of a binary plasmid and a helper plasmid. The two plasmids are used together (thus "binary") to produce genetically modified plants. They are artificial vectors that have both been created from the naturally occurring Ti plasmid found in "Agrobacterium tumefaciens". The binary vector is a "shuttle vector", so-called because it is able to replicate in multiple hosts ("E. coli" and "Agrobacterium tumefaciens"). Systems in which T-DNA and vir genes are located on separate replicons are called T-DNA binary systems. T-DNA is located on the