There are several online atlases of varying depth and complexity, typically in PDF format, that one can print out in toto or as individual charts as needed. One of the most popular is the Tri-Atlas Project (TAP) that portrays the whole sky utilizing three separate atlases (A, B and C), each with progressively more charts, 25, 107 and 571. Each step in the progression increases the plotting limits in terms of both stellar and
Another popular printable atlas is the Deep-Sky Hunter Atlas (DSHA). In this case, the creator utilizes only one atlas of the sky with 101 primary charts to stellar magnitude 10.6 and
So, after all the verbosity, what is my point? Well, in keeping with the title of this article, I have come across a new (to me) online printable atlas set – The Night Sky Maps (NSM). I happened upon this three tiered atlas during a Google search that led me to an approximately year old thread on another site where the creator announced his atlas. There was some modest chatter about it, but otherwise it seems to have been mostly forgotten. Fortunately, the author, a Swedish amateur astronomer named Olle Eriksson provided a link to his site where the atlas is still alive and well. So off I went!
Basically, what Olle has developed is a three level atlas of the entire sky in the same broad sense of the TAP, but using a different platform and less aggressive approach. He developed his atlas using a freeware program many know and use, Cartes du Ciel. By using this as his platform, he had to work within its parameters and structure. However, being a software designer by trade, he had the experience and knowledge to utilize
I will let his own words speak to his motivations for creating the NSM with a couple of quotes. The first from his post announcing the atlas:
“To give some background I already have and use the Interstellarum atlas for when I’m at the eyepiece, and I have the Sky Atlas 2000.0 laying around, and also the Cambridge Atlas Of Herschel Objects. But sometimes I just want something smaller, but not so small that you can't see anything on it. Something that can be lying around on my desk, and be used for checking out a constellation for deepsky objects or for planning a night of observing. An atlas that shows you details, but where each chart covers quite of a bit of sky so that it doesn’t feel like you’re looking through a keyhole.”
and the second from his website:
“An amateur astronomer myself, I had been looking around for a general purpose overview sky atlas for a long time. Not necessarily an atlas to be used at the eyepiece (I already had that), but something that could be lying around on my desk, and be my go to atlas when looking up a constellation, or planning what part of the sky to visit next, or just to remember places already visited. To be that first map you look at when seeing what constellations are visible tonight and you have to decide where to go first.”
So to that end, he developed the NSM, a series of three complete atlases of the sky in sets of 10, 20 and 30 double-spread charts. In order to gain a sense of what the three tiers bring to the table (or desk), below is the general information he provides on his website for comparative purposes:
10 charts (double-page spreads) of the whole sky (both hemispheres).
Each chart 109° x 74° (for A4 w/o inside overlap)
Stars down to magnitude 8.
Deepsky objects to magnitude 8.5.
Labels to varying magnitude.
20 charts (double-page spreads) of the whole sky (both hemispheres).
Each chart 67° x 51°
Stars down to magnitude 9.
Deepsky objects to magnitude 12.5.
Labels to varying magnitude.
30 charts (double-page spreads) of the whole sky (both hemispheres).
Each chart 52.5° x 40°
Stars down to magnitude 9.3.
Deepsky objects to magnitude 13.
Labels to varying magnitude.
As I mentioned, his approach is less aggressive than either the TAP or DHAS online atlases. But his goal here, as he stated, was not necessarily to create an atlas for use in the field under a red light, rather more as a desk reference for planning purposes. The true utility for the observer however, would be up to them. While some may find them field worthy, others may lean toward Olle’s idea of a desk reference. I have taken some time to study them, and will share my perceptions of his atlas.
So as a comparison, I include scans of the chart showing the dipper’s bowl in Ursa Major from each level – the 10, 20 and 30 chart sets. The most pronounced change is from the 10 chart to the 20 chart, with a more modest difference between the 20 and 30 chart sets. Note the galaxies that are unlabeled. That was a particular problem for me.
Night Sky Maps - 10 chart (example)
In looking at all three levels, I found the NSM to be generally attractive and pleasant to the eye. He utilizes black stars on a white background and colored
Each side of the two page spread could be inserted into its own plastic sleeve and mounted in a traditional ring binder so that the whole chart is splayed out flat on the desk or table. Remember, for the 10 chart batch, there are 20 printed pages because of the double-spread format, and thus 40 and 60 for the larger versions. Each atlas set has two index pages, one for the northern hemisphere and one for the southern. They are each centered on the respective poles with an overlap for the equatorial region maps. On the second index chart there is a legend showing the symbols utilized to denote various types
I will note here that the right ascension and declination lines and their hour and degree labels are very in appearance, particularly when printed. Of course the author purposely did that as he doesn’t like heavily weighted coordinate lines and boundaries in a desk reference because he finds them distracting. He does however concede that for field use under a red light they do need to be more visible. Again, we fall back on his intended use for these atlases as a desk reference.
The 10 chart atlas is indeed pretty basic. Multiple constellations are fully contained on each double-spread chart and the fields are very much uncluttered by stars and
As one moves into the 20 chart atlas its increased depth is readily apparent. The proliferation of stars and
I noted in the 10 chart set that there were some objects that were plotted but unlabeled, presumably to lessen the clutter. This also increases in the 20 chart atlas. I find this a bit annoying. What I envision happening is that when one encounters several galaxies within the Virgo Cluster that are unlabelled then the observer will be forced to look elsewhere, such as the IDSA. But even that excellent atlas does not label all galaxies on its chart 45 and 57 coverage of this field. However, the IDSA authors did include two close-up charts (D2 and D3) which delve deeper into this vast field and does label all the plotted galaxies. So that raises the question of why include objects that one does not label. I suspect this may be inherent to the settings within
Finally we get into the 30 chart set, the deepest of the whole project. As shown earlier this atlas plots stars to magnitude 9.3 and
My Thoughts:
I also noticed in my cross checks of the atlas that an incorrect designation pops up here and there. As we all know there are many items within the
Eventually those that undertake unraveling these discrepancies uncover the truth that the original discoverer had merely miscalculated the position but their description was accurate. In most cases formal credit goes to that person and the accepted identifier is typically the one that had been assigned to that discovery. The others are simply erroneous duplications. So this kind of situation is not really significant, but can cause mild confusion from time to time. It can often times be found in almost any atlas in a few cases.
I will relate one instance that did irk me, and it’s not a problem with the NSM, rather one with the IDSA. As I was looking at the 30 chart set, on the left hand page of map 19, and comparing it to my IDSA chart 45, I made a discovery! In the very southwestern corner of Bootes where it borders Virgo, the NSM plotted two galaxies,
Overall, I find the NSM a user friendly charting project that hopefully prove useful for many observers. It does indeed have its limitations of course, and Olle very clearly states his purposes for creating it and his intended use. It is attractive and well laid out, yielding an increasingly deeper view of the sky. If one were to print out all three, they could be placed into sleeves and mounted within a ring binder to use as a desk reference, or in the field if one chooses and accepts its shortcomings in that environment. The labels and objects generally tend to be on the small size, so reading them under a red light might be a little challenging for some. I always have to use reading glasses anyway, so that is not especially an issue in my case.
If there were one major criticism I would voice about the atlas it would simply be the practice of plotting objects that are not labeled. If that has to be done in order to keep clutter down, then why not simply utilize the IDSA (or similar atlas) as a desk reference for planning purposes? I have always preferred an atlas that plots and labels deeper than I can see because I do not like finding objects that I cannot identify in the moment. Granted that can still occur with my 17.5 inch at our dark site using the IDSA and Uranometria. However, that is more the exception than the norm. But however deep my atlas of choice does plot, I want every object within its pages annotated with an identifier. That makes a more complete and useful package.
In conclusion, I wanted to bring this set of progressive atlases to your attention so that if interested, you could download them, review them and see if they are something that you might wish to employ. Personally, I am quite pleased to have them on my machine along with the TAP and DHSA. Though they share a commonality, they are each quite different. For my own planning sessions, I will continue to utilize the IDSA and/or Uranometria in league with Sky Tools 3, plus a few other sources. While I do not see myself utilizing the NSM, I do applaud Olle’s initiative to fill a personal niche and in turn make it available for others. To that end, I include below the links to NSM site, the Tri-Atlas Project site (not mine) and the Deep Sky Hunter Atlas site. Take a look at all of them, and make good use of them, because they are there for your enjoyment, free of charge!
Night Sky Maps: http://www.olle-eriksson.com/night-sky-maps/index.html
Tri-Atlas Project: https://allans-stuff.com/triatlas/
Deep Sky Hunter Atlas: http://www.deepskywatch.com/deep-sky-hunter-atlas.html
But of course ultimately we all like what we like for our own personal reasons.