The TRIATLAS Project Second Edition
(April 2008 – March 2009)
by José Ramón Torres and Casey
Skelton
Three
deep sky atlases up to 9, 11 and 13 magnitude and two complementary editions
Contact emails: José R. Torres and Casey Skelton
Cloudy Night
Forums: discussion threads are here and here
The TRIATLAS Second Edition
● 3
full MAIN DEEP SKY ATLASES up to 9, 11 and 13 magnitude
● 2
standard-alone COMPLEMENTARY EDITIONS
As
I mentioned in these pages, I am a keen deep sky observer. Everybody knows that
the success in our star-hops relies closely on the quality of the atlases we
are using: the better the atlas, the fainter the objects we are able to see
(and the fun). Probably for that reason, I like sky atlases since long. In the
last years, I have bought (and used!) most of the published atlases, but I
cannot find the “perfect atlas”. Probably, there is no ideal single atlas. Some
years ago, I thought that the C section of the Herald-Bobroff atlas was perfect
(large scale, showing faint stars), but I have changed my mind. Sometimes it is
not precise enough, in others there are too many objects and the codes are
often skipped because I prefer using a book to select the DSO to see at the
telescope (I mean, a book gathering tables with data of deep sky objects, DSO),
instead of decoding complex symbols. And finally, not all sky areas were
enlarged. I concluded that I wanted much more stars and DSO plotted, and having
the whole sky plotted at the highest magnification, without meaning this a too
bulky multivolume book. I wanted constellation lines plotted, double stars like
in Herald-Bobroff atlas, conventional symbols, neighboring charts, optional
color printouts, etc).
Thus,
more than one year ago I began to plan my own atlas by modifying my program CNebulaX
to generate high quality vector printouts. The idea was building a set of three
atlases (A,B and C maps), interlinked and
showing the whole sky dome a three magnification levels. That first
edition was still imperfect, with important pitfalls to correct, particularly
label overlaps. Nevertheless, it was very effective at the field, and allowed
spotting practically any deep sky object I tried. I spent nearly a whole year
using it, to learn the good points and the issues to be addressed in a future
second edition. Well, the moment to replace the old atlas has arrived. Now, a
year later, I have prepared a second edition where most of the drawbacks have
been overcome. I would like to share it (free, or course!!!) with everybody as
PDF files.
If
any of the readers have space to store the files, I invite him/her to copy them
in his/her web. I only want two issues: the charts must remain unaltered, and
you must place a link to this page to allow other users to get knowledge about
the TriAtlas features, and to allow them to be updated with regard to news and
incidental corrections. The
atlas is absolutely free and it is my pleasure to share it with everybody.
As
in the first version, there are three sets of charts. The first one (A-Set) consists of
25 A4 charts showing stars up to 9 magnitude, with 70º maps in portrait format.
The second one (B-Set)
includes 107 charts up to 11 magnitude, with 30º charts. Finally, the third
section (C-Set)
includes 571 charts (12º each) up to 12.6 magnitude, more powerful than the
Millennium Atlas, listing for instance all known planetary nebulae and open
clusters, galaxies up to 15.5 magnitude, double stars up to 12.5 magnitude,
etc. The fonts are small
but more readable than in the first release.
I
think that the best is having a look to the enhancements. If you know the first
release, you will appreciate all these changes. I also suggest taking your
favorite atlases and comparing them with the TriAtlas. As a small summary, I
would point out the following features...
Improvements
of the second edition with regard to the first release and some other features
(1) Chart arrangement by decreasing R.A., similar to Uranometria 2000.0 2nd ed: the eastern side of the i chart is the west limit of the i+1 chart
(2) Charts are now in portrait format. This allows viewing a larger region of the
sky, placing two consecutive charts one by the other.
(3) Label overlap problem
practically eliminated. Even highly congested fields can be easily interpreted. The
system is quite good although I think I can still do some more improvements in
the future.
(4) Tips indicating the
location of the problematic objects, which allow labeling
even extremely cluttered regions (eg. Large Magellanic Cloud)
(5) Double stars labeled by
name
and indicated by horizontal tips, but best double stars are plotted like in the
former release although in bold outline
(6) Larger fonts, much more readable
and still good for the scale of the maps. White outlines help to reduce the interferences
of background stars
(7) Legend at the top and neighboring charts at the borders in black background
(8) New symbols
(9) Constellations codes overlaid within each
chart in each set
(10) Framing
charts indicated
to zoom out easily. In the B-charts, the A chart in which each B-chart is
framed is indicated above the chart number (bottom right)
(11) Common
star names (Betelgeuse, Rigel...) and common
names of deep sky objects (Minkowskii Footprint, Intergalactic Tramp...) are now
also printed. Around 200 objects are labelled.
(12) Line sizes now indicate brighter objects (e.g., a brighter galaxy has a thicker outline
than a fainter one). Selecting the bright objects is now much easier!!!.
(13) Much more
galaxies are oriented according to their position angle
(14) Messier objects indicated in bold and larger font. Herschel's
400 objects
are also highlighted in bold font (great
for picking up the best objects).
(15) Polar charts include side R.A. labels
(16) Precession marks in the center of the
maps (1950, 1975, 2000, 2025 and 2050). I placed them thinking in the Burnham's
Celestial Handbook lists of double stars, and other old lists out there, still
very useful.
(17) More double and
variable stars marked in all sets (more relaxed selection criteria)
The charts have been designed to be printed in
a good quality laser printer (use at least 600 dpi and the best quality your
printer allows) in A4 format, which is a standard ISO measurement usual in
European countries, measuring 29 x
The TriAtlas includes plenty of deep sky
objects with enough reference stars to situate them in the sky with high
accuracy; no other current deep sky atlas includes so many DSOs. The
constellation lines and boundaries are now overlaid, which contribute to keep
the perspective. Auxiliary coordinates grid are abundant, but neither
distracting nor intrusive. Coordinates labels are placed at both sides and
bottom of the charts to facilitate binding with the maximal page filling. There
are multiple navigating aids that make usage in the field easy and comfortable,
either to zoom in or out, or to move to neighboring charts. It is also
extremely handy: A4 or similar size allows manipulating the atlas with one hand
whereas we are moving the telescope with the other. A and B sets constitute a
standard-alone atlas by themselves; C-charts allows locating very faint objects
with very good probability of success. Graphically, some of the the features
can be summarized as follows:
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C chart set
(A4 for European and other ISO users, and Letter 8x11" for
About
the C-set
, which includes the most powerful maps:
·
● It consists of 571 charts 12º x 8.5º in PDF files
·
● 1º =
·
● It shows stars up to 12.6 magnitude,
quite good for the map scale, preserving a constant value in the whole atlas
·
● It shows galaxies up to 15.5 magnitude from PGC (all of them are now labeled since cluttering is
not critical anymore). There are around 37,000 galaxies plotted.
·
● It includes the revised version of NGC and IC (from the NGC/IC project), removing discarded objects
·
● ...1200 planetary nebulae
·
● ...1800 open clusters, and all globular clusters
·
● ...SH-2, RCW and other catalogues for bright nebulae (no LBN because of cluttering and
repetitions): 900 objects
·
● ...LDN / Barnard (1850 dark nebulae)
·
● ...Double stars whose main star is brighter than 11th
magnitude (35,000 double stars)
·
● ...Variable stars whose maximum reaches the 12.5
magnitude (29,000 variable stars)
·
● ...There are some quasars (a
few hundreds up to 16.5 mag), the stronger radiosources and
a selection of galaxy clusters (all Hickson's and some Abell's)
·
● Double stars are
now labeled by name.
B chart set
(A4 for European and other ISO users, and Letter 8x11" for
The working horse in the TriAtlas is the B-set, with a linear scale very similar to the Sky Atlas 2000
deluxe but with much more accuracy, stars and deep sky objects. It makes the
location of object extremely easy, and at the same time the scale and
constellation lines helps a lot to relate the sky with the maps. This set is my
personal favorite as master sky atlas.
A chart set
(A4 for European and other ISO users, and Letter 8x11" for
Finally, the A-set has two purposes: to
act as an index for B and C sets, and to display the brightest and best deep
sky objects. This is similar to a 7-mag star atlas but reaching nine magnitude.
This makes it more useful and it allows locating many bright objects without
the cooperation of the other sets.
Complementary
editions (A4/A3 for European users, and Letter/tabloid format for
INTERMEDIATE
B-C SET:
218 charts in A4 / letter – If you want a powerful atlas but you cannot print
the 571 charts of C-set, this can be the solution. It is my personal favorite
edition.
PANORAMIC
B SET:
31 charts in A3 / tabloid – A large scale atlas very similar to Sky Atlas 2000,
but with much more stars (under development)
Download the TriAtlas second edition!!!
NOTE: All links have been updated, contact us if there is any
problem
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A-SET GENERAL INDEX Section A includes a selection of the best deep sky objects and it is very handy
to plan quick deep sky sessions and as a general reference to swap to either
B- or C-maps. 25 charts showing 9 mag stars Size: 47º x 67º portrait layaout,
monochrome Pointers to B- and C-
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Links to download A-SET (A4 page size, ISO): |
Links to download A-SET (letter page, 8x11", |
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● A-SET 2nd edition: 25 charts to 9
mag |
● A-SET 2nd
edition: 25 charts to 9 mag |
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B-SET STANDARD ATLAS Section B includes many thousands of deep sky objects and is an atlas similar to
Uranometria 2000. It can be used in combination with set A and the two key
charts as a standard-alone atlas. 107 charts showing 11 mag stars Size: 21º x 30º portrait layaout, monochrome Pointers to C- maps
and back pointers to A maps |
Links to download B-SET (A4 page size, ISO): |
Links to download B-SET (letter page, 8x11", |
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● B-SET 2nd edition: charts 1-36 ● B-SET 2nd edition: charts 37-72 ● B-SET 2nd edition: charts 73-107 |
● B-SET 2nd
edition: charts 1-36 ● B-SET 2nd edition: charts 37-72 ● B-SET 2nd edition: charts 73-107 |
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C-SET DETAILED ATLAS Section C is the equivalent to Millennium Star Atlas, although with many more deep
sky objects. Use it to find the hardest objects or in very crowded fields. 571 charts showing 12.6 mag stars Size: 8º x 12º portrait layaout,
monochrome Back pointers to B-
and A-maps |
Links to download C-SET (A4 page size, ISO): |
Links to download C-SET (letter page, 8x11", |
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Unfortunately, I have no more space to store other editions. I
have had to remove the pointers to the complementary editions.
TriAtlas C for iPad and iPhone
Norbert Schimdt, a German programmer, developed an application initially for iPhone and later for iPad to make the C-set available in these devices. We granted him permission as far the application was free (as the atlas is and has to be). He has built an excellent application that makes the use of the atlas in the field a truly joy. It is relatively modest in size (400 Mb), navigable (passing charts with the neighboring charts border tags and also through an index chart), red color with controllable brightness (or white background), compact and quick to use. The link to the apple store can be found here. He developed it under the premise that it it would be free for everybody, and we stand here our wish it has to be free and altruist as the TriAtlas itself.
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A look to the (obsolete) first release
(June 2007)
This
is the way I printed the PDF charts, in a single-volume book with the most
comprehensive sky atlas available. I prepared mine including all sets (A, B and
C charts) before summer 2007 holidays, and I was using it in three different
telescopes during all the summer, with an extraordinary performance. It allowed
locating with accuracy many thousands deep sky objects, and it was an
invaluable help for catching objects at the threshold, stellar planetary
nebulae, etc. You just couldn't miss objects because you didn't know exactly
where to fix your attention at the eyepiece field, or because there were too
few stars to spot the place. In addition, the collection of objects was very
comprehensive. No other printed atlas plotted more objects (well ...except the
second edition!!!).
The TriAtlas included navigating aids to jump to the neighboring charts sets at higher magnifications. The chart number was at the lower right area (large outline font). Each chart included nine navigating points giving the chart number of the nearest neighboring charts within the same set, indicated in a bold font in the borders (the corners and in the middle sides). There were also smaller outline numbers in the A-charts indicating the location of the included B- and C- charts, and similar numbers in the B-charts to jump to the C-charts. It was very easy to move around a given area, even at high magnification, and swap between sets. Constellation lines were marked in all sets to make the identification in the sky even easier.
If one preferred a comfortable field atlas instead, he/she
only needed to print sections A and B (around 120 A4 pages). I prepared mine
like in the picture, protecting the pages of moisture with in a folder with
plastic sheets. The B-set had a scale similar to Sky Atlas 2000 deluxe edition,
but with much more stars and objects. Other people printed the atlas in A3 or
similar formats. The maps were vector-based and could be enlarged without
losses in resolution.
The
charts were large
PDF files (=save them to disk before opening). Food
output were obtained printing them with no shrinkage at 600 DPI (I generated my
own charts sending them directly to the printer for a best quality, and PDF
charts were not so perfect).
At
that state the atlas was still unrefined, with overlapped labels and objects,
but nevertheless a very nice work.