NGC 650-1, also known as M 76, is a well known PN because of its inclusion into Messier catalogue. Its moderate magnitude makes it observable in dark skies with the help of an OIII filter, wich gives a good response, to see some details. It's also suggested at least a 6"-8" to see its interesting details.
This nebula is very important because it's been considered the prototype of bipolar planetary nebulas. It is constituted infact by a central bright bar, which is the toroid, and by two opposite lobes. Lobes are clearly more elongated than central toroid (since it is denser so it expands slower); long-exposition Halpha images show also external cone-shaped lobes structures that expand at lower speed: probably these structures had been erupted by the central star during its protoplanetary phase. Central star is small and bright and it's also a tight optical binary system (not a real gravity system, but only a prospective result).
Interesting level : * |
