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Interstellarum Deep Sky Atlas: The Best Yet?

The spiral-bound Deep Sky Atlas and Deep Sky Guide form a complementary two-volume set for the avid deep sky observer. Credit: Alan Dyer

The Best Star Atlas?

The interstellarum Deep Sky Atlas offers valuable features, and objects, not found in other printed or digital star atlases.

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Plus: A complete, hand-curated magnitude 9.5 star atlas in one volume.

Minus: Prices can vary widely on Amazon. And don’t confuse the similar-looking Guide for the Atlas, or the Desk Editions for the very costly waterproof Field Editions.

Summary: The Deep Sky Atlas charts 15,000 deep sky objects, indicating which are suitable for different aperture telescopes, plotting visual sizes, common nicknames, and, for nebulas, what filter works best. The companion Deep Sky Guide is nice to have but not essential. 

Who Is It For? Advanced deep sky observers and astrophotographers looking for a modern star atlas for desk and field use. 

In 2014 when I was at the annual OzSky Star Safari in New South Wales, Australia, star party attendee and atlas co-author Ronald Stoyan showed off his Deep Sky Atlas, then just published by his German company interstellarum. 

The jaws of everyone in attendance, including some of the world’s most experienced deep sky observers, dropped! Despite the Atlas then being only in German, everyone wanted a copy! Fortunately, since then an English-language edition became available, co-published by Cambridge University Press. 

I consider it the best star atlas in print, especially since the closure in late 2020 of Willmann-Bell, the publisher of Uranometria 2000.0, a classic atlas now out of print. Uranometria plotted stars down to magnitude 9.75 over 220 double-page charts. The interstellarum Deep Sky Atlas goes to magnitude 9.5, plotted over 114 double-page charts, each 26 by 28cm (10.2 by 11 inches). Each two-page spread covers two hours of right ascension and 15 degrees of declination. 

The Atlas charts cover two pages; as you turn the pages chart coverage moves from west to east across the sky, in tiers moving north to south. Credit: Alan Dyer

However, the interstellarum Deep Sky Atlas has significant advantages over Uranometria, and most other print atlases intended for serious observers. For one, it is in color, making it easier to distinguish among the different classes of objects. The color scheme is such that the charts work well under red light in the field. 

Unique to the Deep Sky Atlas (and setting it apart from all digital atlases) is that all deep sky objects (clusters, nebulas and galaxies) are labeled with a font and type size that indicates their suitability for 4-inch, 8-inch, 12-inch, or larger telescopes. You can readily see what are the best objects. The rankings are based not just on published magnitudes or theoretical calculations, but on thousands of actual observations compiled by amateur astronomers over two decades. 

The hand curation of entries by experienced observers is what sets the Deep Sky Atlas apart from most other printed atlases and all digital sky charting programs, which often just plot reams of unedited raw data just to up the numbers of objects without regard to what can actually be seen or shot.  Or programs miss objects because they aren’t included in standard machine-readable catalogs. For example, the Deep Sky Atlas plots all the intricate filaments of the large Vela Supernova Remnant; most atlases, even digital ones, fail to display any trace of it, as the components don’t carry common catalog numbers. Ditto the Spaghetti Nebula, aka Simeis 147.

The authors have made sure nebulas are plotted with their actual observed shape, and galaxies with their size and orientation. Hundreds of object nicknames are shown, labels not in official databases but in common use nonetheless. Though being from Europe the authors have missed some names popular among North American observers. 

An area rich in galaxies demonstrates how the Atlas distinguishes small, medium and large telescope targets by font size. Credit: Alan Dyer

Yes, all the usual suspects in the well-known NGC and IC catalogs are included. But the Deep Sky Atlas goes much further. In open star clusters, objects from obscure catalogs such as Basel, Bochum, King, Stock, Tombaugh and Trumpler are plotted. For globular cluster fans, all the Palomar and Terzan challenge targets are shown. 

A total of 536 stellar asterisms are labeled. Few, if any, atlases plot those.

All planetary nebulas in the obscure Abell, Fleming and Menzel catalogs are charted. Uniquely, emission nebulae are accompanied by symbols for the recommended filter: UHC, OIII or H-Beta.

The complete Barnard catalog of dark nebulae is drawn, as well as many dark nebulas from the Lynds catalog, all with outlines and opacity as documented by visual observers. 

The 9,600 galaxies shown include the Local Group members, as well as all Arp, Hickson and Holmsberg catalog members, and all Abell galaxy clusters. 

Double star devotees aren’t forgotten, with 2,950 double and multiple stars plotted using symbols to visually indicate their separation and position angle. 

One of 29 closeups, the two-page chart for the Large Magellanic Cloud is one of the best for sorting out its complex collection of clusters and nebulae. Credit: Alan Dyer

A total of 29 appendix charts plot detailed close ups of crowded regions, such as galaxy clusters and the Large and Small Magellanic Clouds. Two closeup charts cover the rich Coma-Virgo galaxy fields. 

In short, advanced deep sky observers will be in their element perusing the charts. While beginner observers might grow into the charts, they are best to start with a less complex atlas, such as the magnitude 6.5 Cambridge Star Atlas or Sky & Telescope’s excellent magnitude 7.5 Pocket Star Atlas

To complete your library, a companion interstellarum Deep Sky Guide is offered. It is a 230-page visual catalog (which is what it should be called, to avoid being mistaken for the Atlas), providing images or drawings, plus data, on 2,362 selected targets. Entries are arranged to match the Atlas chart numbers and are also grouped by telescope aperture class. I wouldn’t consider the Guide an essential item, but avid deep sky observers will certainly want it. 

The companion Deep Sky Guide presents thousands of images and sketches keyed to the Atlas charts to aid deep sky observers and photographers. Credit: Alan Dyer

Both the Atlas and Guide are also available in Field Editions with pages printed on waterproof plastic, at considerably higher price. But the spiral-bound paper Desk Editions shown here are durable enough they should stand up to careful use at the telescope. I use the Desk Edition of the Deep Sky Atlas almost daily to plan photos and to identify what’s in them. 

Yes, I use digital charts such as Sky Safari, as they can plot stars down to 15th magnitude, and allow zooming into any field for close inspection, framing simulated eyepiece fields, and even tap-and-go telescope control. 

But a print atlas is still a wonderful reference to page through and explore. I consider the Deep Sky Atlas the best of those now available, and superior to digital atlases in many key areas.

interstellarum Deep Sky Atlas:  $85 U.S.

interstellarum Deep Sky Guide:  $100 U.S.

Waterproof “Field Edition” versions of the Atlas and Guide are typically $200 each. 

Website: http://www.deep-sky-atlas.com

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About Alan Dyer

Alan Dyer is an astrophotographer and astronomy author based in Alberta, Canada. His website at www.amazingsky.com has galleries of his images, plus links to his product review blog posts, video tutorials, and ebooks on astrophotography.

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