Used acronyms: NEML=Naked Eye Magnitude Limit, SQM=Sky Quality Meter, TML=Telescope Magnitude Limit, CO=Central Obstruction, delta_m=difference in magnitudes between double star components, RoT=Rule of Thumb, pD_mm=proposed D_mm for resolving a binary (ident with earlier used pA=proposed Aperture), D_mm=Diameter (of scope) in mm, UCAC4=USNO CCD Astrograph Catalog 4th edition
Roberto Botero, Kent, UK
Quote:...Wilfried, I'm using a two-speed external focuser on my C9.25. Without it, I don't think I could see the secondary of either of these stars ...
Quote:I traveled to an alternate viewing spot a few days ago with my gear to get this one.Observed with a f/5.9 8 inch reflector on a night of good seeing (Pickering 7) I recorded the following:340x(3.5mm Pentax XW): transiently observed as resolved to two objects;390x(3.5mm Pentax XW + Paracorr type1): right at the border of resolved and split; the Paracorr sharpened the image just enough to allow this vs viewing with the Pentax alone400x(3mm Radian): split suspected a few times but cannot definitively state as such.This object was fairly tough in this instrument on this night ( I blame my troubles on the swarming mosquitos )