The HB is unique in various ways compared to the typical format that we are accustomed to with a deep sky atlas. To be sure it contains charts, but it expands on the normal concept by including a set of six charts in a large and expansive volume. Each level of chart increases in depth of stellar and
Additionally, the authors have employed a unique series of symbols for each category of object that attempt to convey to the reader various data and characteristics for them in order to aid them in making field judgments regarding both general observability and observable details. In this regard they have gone beyond the realm of simply a detailed atlas into that of an observing guide. It is clear that the authors sought to give the observer more than a robust collection of charts, but also wanted to put more functionality into the field within a single volume. To illustrate this I include the below scan from part of the included legend card. Since I predominantly chase galaxies, I chose the symbology utilized for this particular category of object for my illustration.
The use of symbols to indicate potential observability reminds me of the more recent and currently available Interstellarum Deep Sky Atlas (IDSA) by Ronald Stoyan and Stephan Schurig published by Oculum. As those familiar with the IDSA know, the authors of this fine atlas attempt to predict observability of objects based on
A Deeper Look:
So now after the above generalities, let’s take a look at what the HB brings to the observing table. First, the six sets of charts I mentioned run the gamut from very simple and basic (and frankly in some cases, not overly useful in my view) to deep and detailed. This atlas is quite robust physically, with pages measuring approximately 16.5”x12.0”, with a total of 214 charts across the six sets, and weighing in at about 4.8 lbs. The covers are heavy card stock and the pages made of some type of synthetic paper that is extremely resistant to moisture and tearing. Unlike laminated pages, this material is not significantly glaring under light and is certainly lighter in weight than lamination. The visual format is black stars/symbols on a white sky, which is quite readable under a red light. Additionally, the authors intuitively included a laminated legend card that explains the symbology they employed in the atlas. This is quite handy as it is free floating and can be set aside and quickly referenced at any point during a session. Finally, the entire package is sturdily held together by a 32-pair wire binding.
Here is a summation of each set of charts to give an idea of what they entail:
A-Series: A total of 12 charts, each depicting the entire sky pole to pole and across 24 hours of right ascension. Each displays two curved lines across their length depicting the galactic equator and ecliptic. The series predominantly shows the user the distribution across the sky of various objects (bright stars, constellations and
Finally, each of the A charts have a series of columns aligned under each hour of right ascension displaying a total of seven dates. At the left of these columns is another with seven times between 6 p.m. and 6 a.m. The observer can thus see a corresponding time/date for when a particular hour of right ascension is at culmination.
B-Series: Here we get into the first detailed view of the sky in a series of 16 charts based on the Yale Bright Star Catalogue and includes all stars down to visual magnitude 6.5, plus 461 stars from the catalogue between 6.6 and 6.9. These charts also plot the brighter non-stellar objects. In other words, this series is more akin to a bright star atlas in its nature to give one a basic broader view of the sky without undue clutter. In the margin of each chart is a stellar magnitude scale showing the size dots used to represent the whole magnitude levels plotted. Interestingly, the authors also include the number of each magnitude level that one finds on the respective chart. To aid the observer in planning, they have also included a list of seven dates/times when the particular area depicted culminates. Each chart is labeled with the designation of the adjoining charts along its outer edge, as well as having reference to which C-Series chart a specific field can be found in greater detail. There is ample cross-referencing between the sets in this manner.
The interesting thing here is that there are actually three sets of 16 charts in this series, the B, BS and BM versions. The B sub-set is normally oriented charts that observers are used to seeing in an atlas (north to the top and east to the left). One twist here comes with the BS series, which is oriented for southern observers and displays south to the top and east to the left. This is of course understandable given that the atlas was conceived and published (originally) in Australia. The final 16 chart sub-set in the B-Series is the BM. Here we have another interesting twist, with a group of 16 charts that display no
C-Series: As the large introductory section states, this is the main series of charts, or the meat and potatoes as I like to say. (smiley) It consists of 94 charts plotting all stars to visual magnitude 9.0 and non-stellar objects of total visual magnitude up to 14.0. Each polar region consists of two overlapping charts on opposing pages. The remainder of the sky is presented in gores that flow logically east to west in decreasing right ascension. The far northern and southern declinations are plotted in strips of approximately 2 hours of right ascension, while the mid-nothern/southern and equatorial regions are about 1.5 hours. Each of the main charts depict about 36° of declination. Additionally, each chart has ample overlap with its neighbors to give the observer a nice continual flow. The scaling is consistent chart to chart and presents a nice level of detail for the serious
Some areas, such as the Virgo Galaxy Cluster, are excessively crowded and the authors make no effort to “thin the herd” here to make it more visually presentable. After all, that is what the subsequent close-in charts are for, to increase the scaling to better separate the crowded fields. As with the B-Series, each chart also contains a stellar magnitude “dot” scale and culmination info for the particular chart in its margin.
D-Series: At this point we get to the “zoomed in” charts for 42 specific crowded areas. Unlike the C-Series, the “D” charts are not plotted at a uniform scale. Rather the authors varied the scaling based on the needs of the region being presented in order to give the observer the best level of detail that avoids over-crowding. As the introductory section indicates, these charts limit stellar magnitude to 10.0 in rich galactic regions and 11.5 in galaxy fields. However, they do point out that some charts utilize different limits based on the needs of the field presented, so it always pays to check the magnitude scale in chart margin to confirm the limits. As for non-stellar objects, the authors placed a limit of magnitude 15.0. They also conveniently indicate fields that are further detailed in the next group of charts, the E-Series.
The 42 charts of the D-Series focus on a wide range of rich fields. In particular there are two charts for the polar regions and three covering the Magellanic Clouds. Then there is a group of 22 charts devoted to the rich regions of the Milky Way plane, the Pleiades and the region surrounding Orion’s belt and sword. The remaining 15 charts are devoted to the Virgo and
One example I like to use for charts that focus on a particular region, is the Virgo Galaxy Cluster. In comparing the HB charts D33/D34 to the IDSA D2/D3 charts for the same region, there are noticeable differences. One, the HB close-in charts for this field plot to a stellar depth of magnitude 11.5 versus the IDSA close-in charts to stellar magnitude 10.0. The HB detailed charts also encompass a larger field overall which gives them a nice roomy feel and means more galaxies are brought into view around the periphery that are not found in the IDSA detailed charts. Also, overall the HB charts plot deeper galaxies in the field, though this also highlights one of my nits with the HB atlas. For galaxies it only labels M/
E-Series: This set of 14 charts further drills down into a more discerning set of areas within the sky. In particular, the introductory section states that the D-Series charts do not do proper justice to the Magellanic Clouds, the Virgo Cluster and the Eta Carina area.” To that end, this group of further breaks down the
F-Series: This final set of four charts is definitely of more interest to far southern observers as it focuses exclusively upon the central region of the
To illustrate the differences between chart levels, I provide scanned images of charts around the heart of the Virgo Galaxy Cluster. The area around M84 and M86 is depicted in the following progressively deeper charts, B09, C48, D33 and E10. As a reminder, the B and C series utilizes one chart each to depict this area, while the D series utilizes two charts (D33/34) and the E series four (E9/10/11/12), each more detailed than the previous.
As one can see, there is a lot of meat in this atlas, being physically large and highly detailed. But if one uses an observing table like I do, a large atlas may not be an issue, and the extra roominess of the charts is quite welcome. One of the unique features is of course the way in which the authors have utilized their expansive and varied symbology to encode object data directly into the charts rather than employ a separate field guide. As I mentioned above, they also include a detached two-sided laminated legend card that serves as a reference to their symbology, allowing the user to quickly look up any symbol they find in the atlas to ascertain its full meaning. I can’t say with certainty, but I do wonder this separate legend card served as inspiration for the same thing that one finds in the field edition of the IDSA.
Okay, so what is the bottom line on this thing – what do I like and not like so well? First I will say, as I always do, I’ve never met an atlas I don’t like to some extent. But of course some I find infinitely more useful than others. Sky atlases are unique in their presentation of the sky, and while they share some things in common, then tend to have more differences than similarities. Sometimes the differences can be very subtle, and at time very obvious.
The HB was/is very unique amongst its contemporaries of the time. First, it is both an observing guide and a deep-sky atlas, and yet much more than that. As I have touched on above, it is multiple atlases in one. It covers the sky at various levels within a single volume. The concept is both intriguing and groundbreaking. Ostensibly one would not need to have multiple atlases in the field, such as the Pocket Sky Atlas (PSA) for a wider less detailed view to provide easier orientation, then perhaps Uranometria for deeper detail. With the HB one nearly needs to cross-reference from the lower level B series of charts to the more detailed C, D and E charts for most observers, and possibly the F series for deep southern observers. While many atlases have been printed that include a few detailed charts of specific areas, none have taken the initiative to produce three whole sky atlases (of increasing depth) within one volume such as the HB does with the A, B and C charts.
Despite the positives, all is not rosy with it either. First, is its physical size (16.5”x12.0”) and weight (4.8 lbs). For those that don’t utilize a table or some other support, such as a music stand, it can be a formidable object to handle. I typically utilize both, so in my case this aspect is a non-issue, but certainly one to be aware of. As mentioned above, I am also not a fan of the atlas not labeling galaxies beyond the M/
On the upside, it is physically well made for the field, being printed on special water and tear resistant paper. Its cover is very heavy card stock with a robust wire binder. And again I must mention the unique symbology employed by the authors in an attempt to provide the observer with some sense of an object’s “observability”. While their use of a multitude of object symbol variations can be initially confusing as compared to what we are normally used to in most atlases (both printed and electronic), they do include a free-floating laminted two-sided key card depicting this system that can be easily utilized with any chart in the book.
In reality, as complicated as the symbology may seem to be, it does have one main advantage as compared to the IDSA, which is my current primary field atlas. That would be that the HB prints all labels in equal type size and weight. The IDSA as anyone who uses one knows, utilizes a varied type size and weight schema to impart a sense of “observability” to the reader. While this keeps the number of symbols limited to the standard ones we are all familiar with, it can make some objects/labels plotted in the atlas difficult to read under a red light in the field.
Another fact that may or may not mean something to some is that the entire atlas is printed as black on white – the standard for atlases for decades. While I find this quite easy to read, I must admit I have a personal affinity for color coded atlases, such as the style utilized in the PSA, Sky Atlas 2000.0 and IDSA. I find them easy to read and more attractive to the eye. That said, in the field I see no advantage in visibility for the colored atlases over the black on white versions. After all, Uranometria is of the latter type and an excellent atlas that is heavily utilized by serious observers (including myself).
So, in the end, with all things considered, my choice for a primary field atlas remains the IDSA. For myself, as nice, unique and interesting as I find the HB, I don’t see that it gives me any significant advantage (if indeed any at all) over the IDSA and/or Uranometria (All-Sky Edition), which form my primary one-two punch for field use. I guess for my own use, I find it a bit large for the field, though not anywhere nearly as much as the Great Atlas of the Sky. I will also be quite honest and say that I rarely, if ever, pay attention to the observability rating in either the IDSA or HB. For my money, unless one observes in fairly dark skies, there are too many variables that, in my view, render such predictors problematic.
While the HB has been out of print for some time now, it is still available in the used market. I am quite pleased to have this atlas in my collection, as it is just another bit of uranography that sates my atlaholic addiction. Whether it is for you and whether you wish to seek it out on the various astronomy classified sites, well I leave that up to you. But I think if you are of like mind, and seek out various sky atlases because like myself, you have a respect and love of the art and craft of uranography, I find it hard to believe that you would be disappointed with what you would find between the covers of the Herald-Bobroff AstroAtlas.