π in the sky ·

If you like space, you will love this. The 2017 π Day art imagines the digits of π as a star catalogue with constellations of extinct animals and plants. The work is featured in the article Pi in the Sky at the Scientific American SA Visual blog.

A map of the universe ·

If you like space, you'll love my the 12,000 billion light-year map of clusters, superclusters and voids. Find the biggest nothings in Boötes and Eridanus.The largest map there is shows the location of voids and galaxy superclusters in our visible universe.

Sky Constellation Shapes and Resources

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— Viorica Hrincu

Having recently drawn a few skycharts (Superclusters & Voids, Sanctuary Project), I was frustrated by the lack of parsable resources for the Constellations. Not being able to find a plain-text parsable definition of the constellation figures proved impossible, I created my own.

Quotes on this page are from my conversation with the folks at Sky & Telescope and IAU.

The figures are based on the set drawn by Alan MacRobert for Sky and Telescope. These figures are used in Sky & Telescope's Pocket Sky Atlas by Roger Sinnott and appear in the Wikipedia entries for each constellation as well as on pages by the International Astronomical Union (IAU).

This file contains all the information you need to draw basic star maps (with name and designation labels) and constellation figures.

The file contains a long header that explains the contents. It has been formatted to be friendly to UNIX-style command-line tools — grep away!

This is the most complete (and self-contained) sky constellation dataset of its kind.

All stars in the Yale Bright Star Catalogue are reported (9,114 entries, see below). Each star has an entry like this

where the fields are

The Yale Bright Star Catalogue has 9,110 star entries. There are four additional entries in my file: HR 9602, HR 4796/4796A, HR 5727/5728 and HR 8799/8799A.

These entries are the consequence of SIMBAD records having more than one HR index value.

Each of the 88 constellations has its figure summarized in a line like this

The line reports the figure as a set of comma-delimited connections, each represented by a start and end point, which are identified by the corresponding star's HR index and its Bayer (or Flamsteed) designation. The thickness (which can be 1, 2 or 3) of the connection line is the middle digit.

For each constellation, each figure line is reported individually.

where the fields are

Piece-wise linear constellation boundaries are reported in conbound_pair lines. These boundaries are taken from https://vizier.cds.unistra.fr/viz-bin/VizieR-3?-source=VI/49/bound_18.

For example, the boundaries for Crux are

where each line reports a boundary line between two (ra,dec) points. The fields are

Each conbound_pair line is followed by a conbound_path line that reports the representation of the line segment along a great circle. This makes for nicer paths on maps using projections such as azimuthal equidistant.

 + added constellation boundaries

 + now all stars in Yale BSC are reported

 + records for line points that do not connect fully to a star
   (there's a gap between the end of the line and a star) are modified
   with ra/dec offsets

 + records for line points that are midpoints between two stars are
   annotated with the HR index of both stars

 + added shape for Microscopium, which is a wishbone analogous to
   Telescopium with the bonus that they point at each other

 + modified shape for Telescopium to be a wishbone by adding
   connection between alpha and midpoint between delta 1 and 2.

 + magnitude of alpha Com fixed to 4.32 from 5.08, which is the V
   magnitude reported in SIMBAD.
   
 + fixed midpointa 31-o3 (in Cygnus, which was a little off, as can be
   seen on this map

   old  3    20.25019  42.5288 31-o3Cyg 7735,7751
   new  3.8  20.24253  42.7722 31-o3Cyg 7735,7751

   The stars have Simbad V magnitude 3.8 (31 Omi, o1) and 
   3.98 (31 Cyg, omi2), so the brighter is used.

 + The second entry for delta Vela had a slightly different ra/de

    1.95  8.74506 144.7083 dlt 2Vel
    ...
    5.1   8.74469 144.7003 dlt 2Vel

   I could not find a reason for this -- tt may be that the second
   record refers to delta Vel B (delta Velorum is a triple star
   system: Aa Ab and B).  These stars are extremely close to each
   other so I've changed the second record to point to delta Vel A
   (same as first record).

The data source for the constellation shapes was provided to be by Roger Sinnott in an in-house format used by Sky & Telescope's sky charting software.

I worked from this file to create edits and correction and provide an updated version of this file here. Unless you're working with the S&T software, you're likely to find the file linked to above more useful.

The shapes of all the constellations and the stars that define the asterisms shown in the image below. I also include all the 110 Messier objects with common names in this map (hollow circles).

The map also shows the galactic equator and the ecliptic. The vernal equinox, summer solstice, autumn equinox and winter solstice occur along the ecliptic at right ascension 0/360 (Pices), 270 (Sagittarius), 180 (Vigo) and 90 (Gemini/Taurus).

Whole-sky star charts are traditionally drawn with 360 right ascention on the left in decreasing order towards 0 on the right.

▲ All 88 IAU constellations and their stars. Also included are all 110 Messier objects.

You can download this file as PNG, SVG or PDF.

If you're interested in more astronomical resources, check out my Universe Superclusters and Voids resource page.