Actually, the group of bananas commonly referred to as a bunch at the store is actually a hand, or less commonly tier.
PSR B1509-58 - X-rays from Chandra are gold; Infrared from WISE in red, green and blue/max. A pulsar (from pulse and -ar as in quasar) is a highly magnetized, rotating neutron star or white dwarf, that emits a beam of electromagnetic radiation. This radiation can be observed only when the beam of emission is pointing toward Earth (much like the way a lighthouse can be seen only when the light is pointed in the direction of an observer), and is responsible for the pulsed appearance of emission.
A symphony is a large, multi-movement work for orchestra. It calls for instruments from all four sections (winds, strings, percussion, and brass) and explores a complete range of melody, harmony, rhythm, dynamics, and timbre. That seems like a basic definition, but even that already has a number of exceptions.