Four Free PDF Star Atlas
Mag 7 Star Atlas Project (version 2.0) by Andrew L Johnson http://www.siaris.net/astro/atlas/
Mag 8.4 Star Atlas (Nov 24, 2005) by Toshimi Taki http://www.geocities.jp/toshimi_taki/atlas_85/atlas_85.htm
Tri-Atlas (2nd. edition) by Jose R. Torres http://www.uv.es/jrtorres/triatlas.html
Tri-Atlas C is also a free iTunes download
Deep Sky Hunter Star Atlas http://www.deepskywatch.com/deepsky-atlas.html
Deep Sky Hunter
|Catagories||Mag 7||Mag 8.5||Tri-Atlas A||Tri-Atlas B||Tri-Atlas C||DS Atlas||DS Hunter||Pocket Sky Atlas|
|Document type||Water Proof Book|
|Size||8.5 x 11||8.5 x 11||8.5 x 11||8.5 x 11||8.5 x 11||11 x 8.5||8.5 x 11||9 x 6|
|Mag limit (stars)||7||8.5||9.5||11||12.6||9.5||10.2||7.6|
|Mag limit (DSO)||~11.5||~12.5||~11.5||12.5||15.5||12.5||14.0||11.5|
|Number of chart maps||16||146||25||107||570||80||101||80|
|Selected Area Charts||yes – 1||yes – 3||no||no||no||no||yes -21||yes – 4|
|Index chart included||yes||yes||yes||yes||yes||yes||yes||yes|
|Reference to adjacent maps||no||yes||yes||yes||yes||yes||yes||yes|
|B & W||yes||yes||yes||yes||yes||yes||yes||no|
|Milky Way Outline||no||no||no||no||no||yes||no||yes|
|Color w/ Milky Way Outline||yes||no||no||no||no||no||no||yes|
|Print Format scalable||no||no||yes||yes||yes||yes||yes||n/a|
This is a good chart to use in conjunction with a Telrad finder and naked eye view. When printed on 8.5 x 11 and compared to the S & T Pocket Sky Atlas Cygnus chart 62 there are less nebula, but more important less text per chart. The fewer amount of text make the MAG 7 chart more readable. In addition the star scale size are larger on the S & T Pocket Star Atlas and easier to read at that size. If the charts can be printer on a larger size paper it would make a good rival to the Pocket Star Atlas, however it would not be water proof or as durable. I prefer the selected area map of the Virgo Galaxy Cluster of the Mag 7 chart mainly because it covers more sky area. Be sure to get the PDF or Excel files of DSO found on to bottom of the website.
At magnitude 8.5 these maps complement the view thru your finder scope or binoculars, assuming dark skies of course. I find the map scale pleasing when printed on 8.5 x 11 paper. Not too crowed with text labels and in my opinion the lack of constellation stick figure outline aid to this. Good over lap in RA and Dec with index to adjacent maps. They contain a fairly good selection of DSO objects with complementary text and spreadsheet files. Of course to make this a fine atlas comes with the price of quantity of chart, 146 in this case. The Coma / Virgo Galaxy cluster map contains more reference stars to use when star hopping this region.
Tri-Atlas A, B, and C
These three charts are all based upon the CNebulaX software program. They each contain an enormous wealth of stars and DSO for you to find. Printing these on normal 8.5 X 11 paper is not practicable due to the amount of detail and stars on this scale. The extended constellation stick figures add to the distraction on the page. Navigating the Coma / Virgo cluster at the C scale is difficult enough without the use of “pointer lines” that are used to identify the object name. Best practice is printing on a very large size paper, if you have a printer that can handle this. Alternately use the Adobe Reader to enlarge the map and the Snapshot Tool to copy a portion of the map. This can be pasted into your favorite text document for printing. The C maps may well be a DSO enthusiast alternative to S & T Millennium Star Atlas but it comes with a price when printing at large scale.
I find the amount of text printed on the Tri-Atlas C charts overwhelming in the crowded regions of the Milky Way. The enhanced symbols for the double stars add to the confused look in many cases. In order put as much useful information as possible on the charts, constellation names, reference lines, star names, object labels, object names, and map references numbers will result in a crowded look to the charts with stars down to 13 magnitude. That is the price to pay when looking to create a chart with so much useful information. This is well suited for use with GOTO telescopes, rather than a night of star hopping.
In addition to the charts many supporting files on DSO and Doubles stars are available for download on the website.
Deep Sky Hunter Star Atlas
At slightly larger scale than the Tri-Atlas C these charts present a less clutter appearance of the stars are maped to 10.2 magnitude. Coordinate lines are drawn every 30 minutes in RA and 5 minutes in DEC when compared to bold lines every 5 minutes in RA and 1 minute in DEC for the same area of the sky of the Tri-Start Atlas C charts. It does not cover the depth of magnitude range of deep sky catalogs of the Tri-Star Atlas C charts nor include all of the catalogs, for instance double stars are not labeled.
The larger scale and less clutter is more pleasing to the eye and easier to read and still offering many deep sky object to find in a telescope of modest aperture. There are more deep sky objects plotted than on the Star Atlas 2000. I find these charts very easy to use. For a observer of faint fuzzies and larger aperture may prefer Tri-Star Atlas C over this one, but it is a good alternative between Sky Atlas 200 and Tri-Star Atlas C.
Under the DSO Guide on the website are many supporting file list and illustrated guides in PDF format.
These are my own personal opinions and will differ from your own depending upon your preference.
John D Sabia