NGC 6905 Can you catch the Blue Flash? That's the nickname of NGC 6905, a 12th-magnitude planetary nebula in the constellation Delphinus. NGC 6905 lies 4º directly east of 5th-magnitude Eta (η) Sagittae and 5º northwest of the diamond of Delphinus. Look for its disk set along one side of a tight triangle of 10th-, 11th-, and 12th-magnitude stars. NGC 6905's oval disk measures 42" by 84", which is quite large as planetaries go. The nebula's distinctive blue-green color also will help set it apart from the crowd of field stars. The best views will be through eyepieces that magnify between 100x and 150x. A narrowband nebula filter also will help bring out the nebula's disk. The 15.7-magnitude central star, however, will dodge detection regardless of sky conditions. http://www.astronomy.com/asy/default.aspx?c=ga&id=99&aid=4447 Planetary Nebula aka NGC 6905, PNG 061.4-09.5, PK 061-09.1, He 2-466, ARO 75 RA: 20h22m23.0s Dec: +20°06'16" (Delphinus) Integrated Visual Magnitude: 11.9 Angular Diameter: 40" Mean Surface Brightness: 19.6 Mag/arc-sec² Distance 4700 ly Minimum requirements to detect: 4-inch telescope under dark skies http://www.skyhound.com/sh/archive/aug1/NGC_6905.html Απο απλο googliasma τα βρηκα αυτα που σου εγραψα πιο πανω. Αν δεις στα αποτελεσματα του google στις σελιδες που βγαζει,πιστευω να σε βοηθησουν την επομενη φορα που θα το ψαξεις. Απο τι χαρτες το εψαχνες?? Νικος