Vehrenberg Star Atls
Posted 30 July 2014 - 03:46 PM
Posted 01 August 2014 - 02:01 PM
Posted 01 August 2014 - 03:02 PM
Posted 01 August 2014 - 04:17 PM
The link below will take you to a site that describes the abilities of a number of the current programs available (but by no means all of them!). In many cases choice comes down to what areas of astronomy you are interested in, as some do planets better, or comets, or even variable stars. Reading through each of the descriptions will usually include an indication of their stellar magnitude limits. For myself, I very much favor The Guide and have used various versions (currently 9.0) of it over many years now. Its stellar display goes to around 15th-16th magnitude. There certainly are others that at least approach this same limit.
Posted 01 August 2014 - 05:08 PM
Posted 02 August 2014 - 09:23 AM
Wow, have you mentioned this in the books section? It might fit in classics as well. I have the inverted Vehrenberg Photographic Star Atlas from my asteroid observing days. It is one of my prize possessions. It is still much better than any of my digital star maps. These just don't accurately display faint stars.
John - I was particularly interested by your comments regarding favoring the Vehrenberg. I was a very early purchaser of a set and used it most extensively in my comet observing, but also for locating the positions of variable stars of interest and plotting star charts for them. However, to make this truly useful I always found it necessary to considerably enlarge the images and often to hand-enhance the size of the brighter field stars to get a real impression of the sky at the eyepiece - often a laborious process (today accomplished instantly by a simple key-stroke). Once reasonably advanced digital star mapping software became available I put my Vehrenberg aside and honestly haven't even looked at it again in at least 25 years! Might I ask just how bright the typical asteroids you were tracking using it were?
As perhaps an associated aside concerning old star atlases, let I ask if any observing enhusiasts here remember Webb's Atlas of the Stars? It was a great little book (about 7"x10" is size) whose many pages illustrated the sky from the north celestial pole down to declination -23 (IIRC) and plotted stars to 9th magnitude. This was available from the very late 1930's until the early 50's. The only other alternative to such detailed star charts at the time were rare copies of the large Beyer-Graff Star Atlas and the even larger-sized and vastly more expensive BD. I got to know the author, Harold B. Webb, and almost got the book re-issued commercially in the late 1960's. I always regret that the deal fell through (not his nor my fault) as it was such a handy and useful at-the-eyepece tool, especally for binocular observers.
Posted 02 August 2014 - 11:29 AM
Posted 07 August 2014 - 12:17 AM
You say Most any modern planetarium program shows fainter stars than mag. 13. I have a few on my I Pad, the best one is Sky Safari (Middle Version) and it only goes to mag. 9. I would love to get one that goes deeper, can you suggest one.
fred, some planetarium programs only load stars to a specific magnitude limit; to increase the limit you have to download additional stellar files. at least this is how stellarium works, and i'd recommend that as a desktop program.
unfortunately the ipad programs are more limited in their display attributes, so although my ipad version of sky safari pro 3.8.5 will show stars down to magnitude 15 (there is a slider in the system settings) it (1) seems very buggy (it shows a different magnitude limit every time i open the system settings; i set it to 10.5, then opened it again and it said 14.3, then opened it a third time and it said 15.3) and (2) the pixel rendering is too crude to use as a visual guide, and (3) the stellar lookup screens that give precise magnitudes are much too bright to use at the eyepiece.
the problem with the vehrenberg and any stellar photographic atlas is that the star image sizes do not correspond well to naked eye visual magnitudes; it's also very hard to use the vehrenberg chart scale at the eyepiece. you may need to lower your asking price.