Sunday, March 26, 2017

Celestial map update

I have updated the d3-celestial sky map with quite a few new options. See here:

As they are:

Star designations and proper names are now handled separately, so both can be displayed at once for those stars that have proper names, preferably at different locations relative to the stellar disk, which is settable in the configuration

It is now possible to display grid values at each line (so far only in the configuration), with the options to display them around the outline, in the center, or with an array of degree-values indicating the location where the line of values is crossing the respective other direction. So latitude-lines for longitude and vice-versa. And it works in quite a lot of cases. too.

Finally, the constellations are now ranked by prominence, with the possibility to assign a different font to each of the ranks, e.g. to display the names with different sizes. The ranks are assigned by the following criteria:
1. Rank: Large constellations with lots of bright stars. E.g. Orion, Ursa Major
2. Rank: Large constellations *or* with one or more really bright star(s). E.g. Monoceros, Crux 3. Rank: The rest, Circinus, Sagitta, the like.

And the reason for this? Well, to improve my giant wall map with all the features I'd like it to have. You can download the original by clicking on the image below, but be aware it is quite large, 3.7MB. As you can see, it also includes the log-scale universe I made last month.

Finally, I have made more parameters available interactively via the integrated form, the size formulae for stars and DSOs, as well as the Milky Way color and opacity. Next up are more style settings.

See some more d3-celestial examples here, play with it here or check out the documentation and/or fork/download the source from the GitHub repository.

Monday, March 6, 2017

Logscale Universe

I have done a map of the Solar System with a logarithmic scale before, this one extended toward the nearest stars, so it seems logical - to me at least - to extend it right towards the end. And here is the result: The log-scale universe.

Scroll right until the End Of The Universe, or click on it and enjoy in full. Or should that be the Beginning Of The Universe, since that is the limit of how far we can see it. If you prefer a black background, take this.

My main inspiration was this map by Gott, Juric et al. from 2005, but I wanted more detail, so I had to search for a lot of data to complete it. I also didn't like the geocentric origin, so my map starts out heliocentric :P. Below is a list of all the
Sources:
Solar System: NASA JPL Solar System Dynamics, except
Small bodies: mpccorb.dat from Minor planet center
Stars: Extended Hipparcos Compilation (XHIP), Anderson et al., 2012
DSOs:
Milky Way Global Clusters: MWGC, Harris, 2010
Local Group galaxies: see the Milky Way halo and Local Group pages for the sources.
Messier catalog SEDS.org and selected Caldwell objects
More Galaxies: Catalog of Local Volume galaxies, Karachentsev et al., 2013
Cosmicflows-2 catalog, Tully et. al., 2013
2M++ galaxy redshift catalogue, Lavaux et al. 2011
SDSS DR-13, 2015
and Galaxy Clusters & Superclusters: Superclusters of Abell and X-ray clusters, Einasto, 2001
and finally Ned Wright's cosmology calculator was a great help in figuring out comoving distances from redshift using current cosmological parameters (according to the Planck results):
H0: 67.74, Ωλ: 0.6911, Ωm: 0.3089
I hope I got that right.

Tuesday, February 28, 2017

Solar System Missions Update 03/2017

Here's my map of all active and future Solar System Missions as of March 1st 2017.

Another new mission on the list, the second Indian Mars Orbiter Mission (MOM-2), due to launch in 2018. And Juno will last until 2021, assuming they get their mission extensions approved.

Tuesday, January 31, 2017

Solar System Missions Update 02/2017

Here's my map of all active and future Solar System Missions as of February 1st 2017.

New destinations aplenty this month. There's metal asteroid 16 Psyche, target of the (drum roll) Psyche mission, and 52246 DonaldJohanson for the Lucy mission (no twitter yet) The outer Solar System got quite a bit more populated with all the Jupiter Trojans also targeted by Lucy. See the map for all their names.

Friday, January 13, 2017

Elongation chart: learnination applied

When I recently printed an ecliptic-longitude version of the elongation chart to accompany a celestial wall map, I found it not quite ideal for the task. So I made some changes to the chart for better visibility in printed form on a wall, and now I'm propagating these changes to the elongation charts: Larger fonts, lines, symbols and the colors of the planet lines darker and easier to distinguish. So Venus is now green and Mercury pink, but that's a small price to pay for better visibility, I hope.

As a bonus, the 10-year ecliptic longitude chart is also linked at the elongation page.

Sunday, January 8, 2017

Holiday project: Celestial wall map

Things to do with the D3-Celestial star map: Wall poster.

Detail 1: Orion

Detail 2: Sagittarius

Source image for the map:

Bonus features, glue the to the poster or copy&paste them onto the image if you prefer planning ahead (ahem):

Planet positions charted by ecliptic longitude over a 5 year period (based on my elongation chart Same chart, 10 year period

Major asterisms (interactive version)

Grid/planes/brightest stars (<3.5mag)

Lessons learned: For 100x50cm, 4000 pixels width is sufficient. Configuration settings different from default:

var config = { 
  width: 4000,    
  projection: "aitoff",  //Map projection used
  transform: "equatorial",   //Coordinate transformation equatorial
  center: [180,0,0],
  stars: {
    show: true,    //Show stars
    limit: 8,      //up to maximum stellar magnitude
    colors: true,  //Show stars spectral colors, if not use "color"
    namestyle: { fill: "#ddddbb", font: "12px Georgia, Times, 'Times Roman', serif", 
                 align: "left", baseline: "top" },
    proper: false, //Show proper names (if none shows designation)
    desig: false,   //Show designation 
    namelimit: 5,   //Maximum magnitude with name
    size: 10,
    data: "stars.8.json" // Data source for stellar data  
  },
  dsos: {
    show: true,    //Show Deep Space Objects
    limit: 16,      //up to maximum magnitude
    names: true,   //Show DSO names
    namestyle: { fill: "#cccccc", font: "12px Trebuchet, Helvetica, Arial, sans-serif", 
                 align: "left", baseline: "bottom" },
    desig: true,   //Show short DSO names
    namelimit: 16,   //Maximum magnitude with name
    size: null,    
    data: "dsos.bright.json"
  },
  constellations: {
    show: true,    //Show constellations 
    names: true,   //Show constellation names 
    namestyle: { fill: "#cccccc", font: "18px Trebuchet, Helvetica, Arial, sans-serif", 
                 align: "left", baseline: "top" },
    desig: true,   //Show short constellation names (3 letter designations)
    lines: true,   //Show constellation lines 
    linestyle: { stroke: "#cccccc", width: 1.5, opacity: 0.6 },
    bounds: true,  //Show constellation boundaries 
    boundstyle: { stroke: "#ccff00", width: 1.5, opacity: 0.8, dash: [4, 8] }
  },
  mw: {
    show: true,    //Show Milky Way outlines
    style: { fill:"#ffffff", opacity:"0.12" }
  },
  lines: {
    graticule: { show: true, stroke:"#cccccc", width:1, opacity:.6 },   
    equatorial: { show: true, stroke:"#aaaaaa", width:1.5, opacity:.7 }, 
    ecliptic: { show: true, stroke:"#66cc66", width:1.5, opacity:.7 },  
    galactic: { show: true, stroke:"#cc6666", width:1.5, opacity:.7 },  
    supergalactic: { show: true, stroke:"#cc66cc", width:1.5, opacity:.7 } 
  }
};

[Update] Here is the image of the complete map with all the above options
Next up: grid coordinate references on the map

See some more examples here, play with it here or check out the documentation and/or fork/download the source from the GitHub repository.

Saturday, December 31, 2016

Solar System Missions Update 01/2017

Here's my map of all active and future Solar System Missions as of January 1st 2017.

Almost the same one Emily Lakdawalla uses for her preview of robots beyond Earth orbit 2017 on the Planetary Society blog. Can you spot the difference 🤔