[AJames]

Originally Posted by ausastronomer

May I also point out that in the bookcase full of Astronomy books I own. I don't own one that doesn't contain an error of some description. The book you recommend, Hartung's, while a tremendous book, contains a couple of glaring errors. Most noteable, his omission of X Velorum, in Vela. One of the best double stars in the entire sky IMO, which is visible naked eye, able to be split in my 16 x 60 binoculars, yet unable to be seen by Hartung in his 12" reflector. He must have left his sunnies on the night he covered Vela

Very curious that you quote the double star x Velorum / DUN 95, which is one of the most brilliant in the sky. It is one of my personal favourites as well, and I have written about this colourful system on several occasions - including having coining Alberio Australis - mainly just to get the northerners attention to another great colour contrasting pair.
Hartung left it off his list because it is a very wide system ~51.9 arcsec, and like many of the pairs he mentions, the majority are less than 20 arcsec. This follows from R.T.A. Innes 1899 catalogue, which has a similar limitation. Although I cannot be proven, much of the information on the changes he describes in double stars of these pair used Innes and the Index of Double Stars of 1963. Hartung Edition 2, is very similar to the original in this regard. (The reason is probably the system is likely not a binary star, whose probability of being attached is fairly small.

Whether this is a glaring error or not is debatable, especially as it was written in 1968 and there in nothing else like it for the time.

As to errors, yes, nearly ALL references do have a few mistakes and omissions. Even my own text generally have various mistakes - often from missing information, newly available data, or having interpreting things just wrongly. I really try hard to avoid it. I too have been heavily criticised over the years for some of my own words.

As to the huge number of errors in Volume 7.... well I've already made my point.

Thanks for your honest appraisal,

Regards,
Andrew