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Mag: B=?, V=?
NGC 6766. Things are not looking good for this stellar planetary discovered by Pickering. The NGC position (precessed to 1950) is 19 08.6, +46 11, while Pickering himself gives 20 08.8, +46 19 in his collection of nebulae found at Harvard (Harvard Annals 60; I have not seen his note in AN 105, 355 where he actually announced the discovery.) Assuming that the "20" hours he gives is actually a typo for "19", the HA 60 position would be 19 08.7, +46 15, still far enough off the NGC position to make locating a "stellar" nebula in the rich Milky Way field a headache. There are no planetaries obvious in DSS fields around Pickering's positions, so examination of objective prism plates would seem to be necessary to recover his object if it exists.
Pickering's method of finding the planetaries is interesting: he simply swept the sky looking through a low-dispersion spectrograph. The stars' spectra must have appeared mostly continuous through his instrument, while the planetaries would still be stellar because most of their visible light is concentrated in the emission lines of oxygen at 4958 and 5007 angstroms.
The RNGC (Sulentic and Tifft 1973) notes that this is a nonexistent object. Their coded description reads NF S.
The Messier objects
The Bennett objects
The Caldwell list
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