Free Magnitude 7 Star Charts

Andrew L Johnson started the Free Mag 7 Star Atlas Project on his personal web site, but it proved too popular, and it needed a more robust server. It is now hosted on Cloudy Nights, one of the most popular astronomy communities on the web.

This project has a Creative Commons License that allows you to freely download, use, and/or distribute the work for non-commercial purposes. You can also create and distribute derivative works. If you want to download each file one-by-one, you’ll get a link to Cloudy Nights. I’ve converted the tar.gz compressed files to zip files for easier access and you’ll get a link from this site. I’ve also taken the liberty of downloading the almanac version with Milky Way imprint from the Internet Archive, which has the same Creative Commons License. I’ve preserved the author’s credits section at the bottom since this is an impressive work and it took many pieces!

Note: If you want more detailed star maps, take a look at Taki’s 8.5 Magnitude Star Atlas, which can be found at http://takitoshimi.starfree.jp/atlas_85/atlas_85.htm. Taki includes more detail, but the atlas includes 150 pages instead of 21 with the Mag 7 atlas!

Almanac

The almanac is a single file with all of the pages, including the Milky Way. Click the map image to download the PDF file hosted by SPAC.

The original Star Atlas is hosted at the Internet Archive.

Object Index

The author also supplied an object index table. For convenience, SPAC is hosting the PDF or you can download the PDF at the Internet Archive.

Black and White Charts

This is a B&W version of the maps with each page a separate PDF file. SPAC is hosting the zip file of all of the charts. Click that link or the image below to download a zip file:

The main hosting page is on Cloudy Nights allows you to download individual pages.

Color Charts

This is the color version of the maps without the Milky Way. Each page a separate PDF file. SPAC is hosting the zip file of all of the charts. Click that link or the image below to download a zip file:

The Cloudy Nights page allows you to download individual pages, if you wish.

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Notes

Double Stars

I selectively marked double stars using the Washington Double Star catalog with the following criteria: only stars with a separation of at least 0.5 arc-seconds, a secondary component of Magnitude 11 or brighter, and were based on at least five observations, were marked as doubles on the charts.

Because separate, non-synchronized data sources were used, occassionally the star positions are not identical, resulting in the double-star marker (the thin horizontal bar) and the star being slightly offset. Also, since the magnitudes may be slightly different in each source, stars close to the Mag-7.25 cutoff may be mismarked. This means either a star could be plotted but not marked as a double (if the WDS listed it as fainter than the cutoff), or a marker might be plotted without its star — the latter being the only case you can readily notice. These are pretty rare occurrences and I’m not sure any reconciliation is worth the effort at the moment.

Viewing/Printing

These PDF’s display and print as expected on Acroreader-5.05 on my Linux box. Your results may vary depending on platform and PDF viewer.

Credits:

The following software and data are being used in this project:

• PP3 celestial charting program and its data/catalogs
• LaTeX (typesetting engine used by PP3)
• Ruby and Perl programming languages (for preprocessing my own pp3 input format, and various database and data manipulation tasks)
• SQLite database engine
• Additional data derived from:
  • Tycho-2 star catalog/database
  • Washington Double Star (WDS) catalog/database
  • NGC/IC catalogs (Wolfgang Steinicke’s corrected version)
• Linux (actually Slackware)

Additional thanks to:

• Several members of the Cloudy Nights community for providing some feedback and suggestions.
• The Cloudy Nights organization for hosting these charts here, and all their hard work in building and maintaining the nicest online astronomy community available (in this author’s humble opinion) — it’s not just a resource or community, it’s an education!

Sincerely,
Andrew L. Johnson (jandrew on CN) UPDATED – Version 2.0, April 2007

The latest version corrects a few errors in the first edition, uses a new color scheme that avoids red, and uses new symbols for different DSOs (no legend, but it isn’t hard to figure out). Galaxy elipses on charts 2 through 19 reflect their approximate position angles — elipses on the two polar charts are not corrected for North not being up, but still provide approximated relative position angles. Double stars were marked using more recent data from the Washington Double Star catalog (2006.5). Chart-11a (the Coma Berenices – Virgo region closeup) now plots stars to 8.5.

The deluxe milky way version is also available, it is a single PDF file of about 18MB, and I’ve uploaded it to:

Archive.org

(the link to the PDF is on the left of the page in the “View the book” box)

Copyright © 2005 Andrew L. Johnson