<p>Shameless self-plug: I made a catalog of the BSC5P that has 3D positions, colour, and other goodies ready for use:</p>
<ul>
<li><a href="https://github.com/frostoven/BSC5P-JSON-XYZ" rel="nofollow noreferrer">https://github.com/frostoven/BSC5P-JSON-XYZ</a></li>
</ul>
<p><strike>The catalog is released to public domain under <code>CC0</code>.</strike></p>
<p>The catalog is released under <code>CC BY 4.0</code> (relicensed because of <a href="https://www.latimes.com/business/hiltzik/la-fi-hiltzik-getty-copyright-20160729-snap-story.html" rel="nofollow noreferrer">this garbage</a>) .</p>
<br>
<hr />
<br>
<p>In case it's useful, I detail below how I created it.</p>
<p><em>Obtaining the raw data</em></p>
<p>I started with the BSC5P data from <a href="https://heasarc.gsfc.nasa.gov/" rel="nofollow noreferrer">HEASARC</a>,
but 95% of the stars in that catalog had no parallax information.</p>
<p>I then searched for an online catalog that could be queried for information. <a href="https://gea.esac.esa.int/archive/" rel="nofollow noreferrer">Gaia</a> seemed like a good source, but the query engine is very complicated. I finally found the <a href="https://simbad.u-strasbg.fr/simbad/" rel="nofollow noreferrer">SIMBAD Astronomical Database</a>, which has an API for obtaining star info by any name you have for that star. I wrote a script capable of querying SIMBAD. Then, using the all the star names obtained from HEASARC's BSC5P, I pulled all data SIMBAD had on each star in the BSC5P.</p>
<p><em>As a side note, if you wish to automate SIMBAD queries, please keep your queries to 4 or less per second to prevent flooding their system.</em></p>
<p><em>Processing the raw data</em><br></p>
<p>I wrote another script to process the downloaded SIMBAD data. I found that roughly 50 of the 9110 stars still had missing parallax. It's a huge improvement over 8600+ stars with missing parallax, so I kept it. For that remaining ~50, I eventually manually researched every individual one and added parallax in myself. This is done via <a href="https://github.com/frostoven/BSC5P-JSON-XYZ/blob/primary/amendmentFactory/amendAsNeeded.js" rel="nofollow noreferrer">yet another script</a> I wrote, which exists purely as an amendment mechanism that modifies SIMBAD data mid-parse-stage to output a single unified catalog.</p>
<p><em>3D positions</em><br></p>
<p>With all stars now having right ascension, declination, and distance, we can estimate coordinates. The only real issue here is uncertainty in distance: some stars have wildly uncertain values (Betelgeuse for example is somewhere between 153 and 196 parsecs away - that's a huge amount of variation). Being 3D however, we cannot place a single star in a range of somewhere and somewhere else - it needs to be in a single location. The compromise in this case is that we discard uncertainty and pretend the star is in the middle of that range (this is stated in the catalog's README as well).</p>
<p>The simplest way I could come up with to create the 3D positions are as follows:</p>
<ul>
<li>Create an object in a 3D space at position <code>0,0,0</code>. We'll call this the center of the ecliptic.</li>
<li>Align the 3D object with the world's 'forward' direction.</li>
<li>Set the rotation of the object to the star's right ascension, converted from time units to degrees.</li>
<li>Rotate the object along the star's declination.</li>
<li>Move that object along its new forward-facing direction. Distance moved is <code>1 / parallax</code>, or star distance in parsecs.</li>
<li>Record the object's new 3D position.</li>
</ul>
<p>The script that generates the 3D coordinates may be found <a href="https://github.com/frostoven/BSC5P-JSON-XYZ/blob/primary/utils/project3d.js" rel="nofollow noreferrer">here</a>. It uses <a href="https://threejs.org/" rel="nofollow noreferrer">three.js</a> for the 3D calculations.</p>

CC BY-SA 4.0
2021-12-24T23:34:03.293Z
Just for reference https://github.com/astronexus/HYG-Database is a slightly larger list that includes fainter stars
Barry Carter
CC BY-SA 4.0
2021-10-10T06:23:37.400Z
This looks handy. Can you detail here how you derived the x,y,z positions and the provenance of all the data used for that.
ProfRob
CC BY-SA 4.0
2021-10-10T07:30:26.543Z
@ProfRob With a lot of effort :P. For the `x,y,z` coordinates I create an object in a 3D space at position `0,0,0`, facing in the 3D world's base 'forward' direction. I then set the rotation of the object to the star's right ascension, and rotate it along the declination. I then move that object along its new forward direction N amount of parsecs, and record the object's new `x,y,z` coords. The data was mostly taken from SIMBAD because it allows automated API queries (which I wrote a script for), but that gave incomplete data (esp. parallax). The remaining data was painstakingly researched.
aggregate1166877
CC BY-SA 4.0
2021-10-11T05:01:05.310Z
@ProfRob I've updated my answer to contain more detail.
aggregate1166877
CC BY-SA 4.0
2021-10-11T06:33:51.960Z
+1 Nice work. For your catalogue to be useful for anything but graphics you must retain: (1) the parallax and it's uncertainty because uncertainties matter in many applications and, if the uncertainty is large, the distance isn't just 1/parallax; (2) the source of the parallax because "Simbad" isn't a source and what Simbad chooses to list as the parallax of a star can change.
ProfRob
CC BY-SA 4.0
2021-10-11T18:28:43.303Z
@ProfRob Interesting, did not know uncertainty could still be useful. I'll include uncertainty in the next batch of major updates and do some research on the rest.
aggregate1166877
CC BY-SA 4.0
2021-10-09T23:57:46.730Z
2022-01-04T02:52:01.133Z
2022-01-04T02:52:01.133Z
aggregate1166877
<p>One of the most popular ones known as <a href="http://heasarc.gsfc.nasa.gov/W3Browse/all/hipparcos.html" rel="nofollow">HIPPARCOS</a> lists parallax which is indicative of distance.</p>

CC BY-SA 3.0
2014-04-01T02:05:04.563Z
2014-04-01T02:05:04.563Z
Cheeku
<p>I have come across a number of star catalogs that list stars by right ascension and declination, along with other data such as magnitude.</p>

<p>Is there a star catalog that lists the 3-D position of stars (e.g. includes distance from the sun, or otherwise specifies a 3-D position)?</p>

CC BY-SA 3.0
2014-03-31T07:33:41.157Z
Which catalgoues have you come across? 
One of the most popular ones known as HIPPARCOS(link ahead) lists parallax which is indicative of distance.
http://heasarc.gsfc.nasa.gov/W3Browse/all/hipparcos.html
Cheeku
CC BY-SA 3.0
2014-03-31T15:26:05.363Z
Thank you, I missed that set.  Do I understand correctly that parallax in the HIPPARCOS set can be measured for stars out to about 1600 light years?
Eric J.
CC BY-SA 3.0
2014-03-31T17:35:31.790Z
I am sorry but I have only used it for amateur observations and didn't pay attention to that detail. Plus, I can't find that out in the documentation. Maybe it is in the papers. Yet sorry.
Cheeku
CC BY-SA 3.0
2014-03-31T18:32:26.040Z
@EricJ. Has Cheeku's comment resolved your question? If so, it should be made into an answer (by him, so you don't have to worry about that). If not, what detail are you still lacking? Consider working this into the body of your question.
called2voyage
CC BY-SA 3.0
2014-03-31T20:43:51.880Z
@called2voyage: His comment is certainly worthy of an upvote, and may well end up being the accepted answer.  Not sure if there is a source that lists distance estimates for stars whose distance can only be inferred by methods other than parallax.
Eric J.
CC BY-SA 3.0
2014-03-31T20:44:30.260Z
@Cheeku: If you convert your comment into an answer, I will certainly upvote it and may accept it if no other answers are proposed that also cover more distant stars.
Eric J.
CC BY-SA 3.0
2014-04-01T01:38:10.880Z
Have you tried the usual Vizier/simbad/Aladin http://cds.u-strasbg.fr/ ?
Py-ser
CC BY-SA 3.0
2014-04-01T02:05:47.570Z
Okay, done. At a glance, it seemed such a shame to write a single sentence as an answer.
Cheeku
<star><distances>
3D Positions of Nearby Stars
Eric J.
# 3D Positions of Nearby Stars

(Asked by: username_0 on 2014-03-31)

I have come across a number of star catalogs that list stars by right ascension and declination, along with other data such as magnitude.

Is there a star catalog that lists the 3-D position of stars (e.g. includes distance from the sun, or otherwise specifies a 3-D position)?

**Tags:** star, distances

> **Comments:**
> **username_1**: Which catalgoues have you come across?  One of the most popular ones known as HIPPARCOS(link ahead) lists parallax which is indicative of distance. http://heasarc.gsfc.nasa.gov/W3Browse/all/hipparcos.html  
> **username_0**: Thank you, I missed that set.  Do I understand correctly that parallax in the HIPPARCOS set can be measured for stars out to about 1600 light years?  
> **username_1**: I am sorry but I have only used it for amateur observations and didn't pay attention to that detail. Plus, I can't find that out in the documentation. Maybe it is in the papers. Yet sorry.  
> **username_2**: @EricJ. Has username_1's comment resolved your question? If so, it should be made into an answer (by him, so you don't have to worry about that). If not, what detail are you still lacking? Consider working this into the body of your question.  
> **username_0**: @username_2: His comment is certainly worthy of an upvote, and may well end up being the accepted answer.  Not sure if there is a source that lists distance estimates for stars whose distance can only be inferred by methods other than parallax.  
> **username_0**: @username_1: If you convert your comment into an answer, I will certainly upvote it and may accept it if no other answers are proposed that also cover more distant stars.  
> **username_3**: Have you tried the usual Vizier/simbad/Aladin http://cds.u-strasbg.fr/ ?  
> **username_1**: Okay, done. At a glance, it seemed such a shame to write a single sentence as an answer.  

---

## 2 answers

### Answer by username_1 on 2014-04-01. Score: 4 | Accepted answer

One of the most popular ones known as [HIPPARCOS](http://heasarc.gsfc.nasa.gov/W3Browse/all/hipparcos.html) lists parallax which is indicative of distance.


---

### Answer by username_4 on 2021-10-09. Score: 9

Shameless self-plug: I made a catalog of the BSC5P that has 3D positions, colour, and other goodies ready for use:

* <https://github.com/frostoven/BSC5P-JSON-XYZ>

The catalog is released to public domain under `CC0`.

The catalog is released under `CC BY 4.0` (relicensed because of [this garbage](https://www.latimes.com/business/hiltzik/la-fi-hiltzik-getty-copyright-20160729-snap-story.html)) .

  

---

  

In case it's useful, I detail below how I created it.

*Obtaining the raw data*

I started with the BSC5P data from [HEASARC](https://heasarc.gsfc.nasa.gov/),
but 95% of the stars in that catalog had no parallax information.

I then searched for an online catalog that could be queried for information. [Gaia](https://gea.esac.esa.int/archive/) seemed like a good source, but the query engine is very complicated. I finally found the [SIMBAD Astronomical Database](https://simbad.u-strasbg.fr/simbad/), which has an API for obtaining star info by any name you have for that star. I wrote a script capable of querying SIMBAD. Then, using the all the star names obtained from HEASARC's BSC5P, I pulled all data SIMBAD had on each star in the BSC5P.

*As a side note, if you wish to automate SIMBAD queries, please keep your queries to 4 or less per second to prevent flooding their system.*

*Processing the raw data*

I wrote another script to process the downloaded SIMBAD data. I found that roughly 50 of the 9110 stars still had missing parallax. It's a huge improvement over 8600+ stars with missing parallax, so I kept it. For that remaining ~50, I eventually manually researched every individual one and added parallax in myself. This is done via [yet another script](https://github.com/frostoven/BSC5P-JSON-XYZ/blob/primary/amendmentFactory/amendAsNeeded.js) I wrote, which exists purely as an amendment mechanism that modifies SIMBAD data mid-parse-stage to output a single unified catalog.

*3D positions*

With all stars now having right ascension, declination, and distance, we can estimate coordinates. The only real issue here is uncertainty in distance: some stars have wildly uncertain values (Betelgeuse for example is somewhere between 153 and 196 parsecs away - that's a huge amount of variation). Being 3D however, we cannot place a single star in a range of somewhere and somewhere else - it needs to be in a single location. The compromise in this case is that we discard uncertainty and pretend the star is in the middle of that range (this is stated in the catalog's README as well).

The simplest way I could come up with to create the 3D positions are as follows:

* Create an object in a 3D space at position `0,0,0`. We'll call this the center of the ecliptic.
* Align the 3D object with the world's 'forward' direction.
* Set the rotation of the object to the star's right ascension, converted from time units to degrees.
* Rotate the object along the star's declination.
* Move that object along its new forward-facing direction. Distance moved is `1 / parallax`, or star distance in parsecs.
* Record the object's new 3D position.

The script that generates the 3D coordinates may be found [here](https://github.com/frostoven/BSC5P-JSON-XYZ/blob/primary/utils/project3d.js). It uses [three.js](https://threejs.org/) for the 3D calculations.

> **Comments:**
> **username_6**: This looks handy. Can you detail here how you derived the x,y,z positions and the provenance of all the data used for that.  
> **username_4**: @username_6 With a lot of effort :P. For the `x,y,z` coordinates I create an object in a 3D space at position `0,0,0`, facing in the 3D world's base 'forward' direction. I then set the rotation of the object to the star's right ascension, and rotate it along the declination. I then move that object along its new forward direction N amount of parsecs, and record the object's new `x,y,z` coords. The data was mostly taken from SIMBAD because it allows automated API queries (which I wrote a script for), but that gave incomplete data (esp. parallax). The remaining data was painstakingly researched.  
> **username_4**: @username_6 I've updated my answer to contain more detail.  
> **username_6**: +1 Nice work. For your catalogue to be useful for anything but graphics you must retain: (1) the parallax and it's uncertainty because uncertainties matter in many applications and, if the uncertainty is large, the distance isn't just 1/parallax; (2) the source of the parallax because "Simbad" isn't a source and what Simbad chooses to list as the parallax of a star can change.  
> **username_4**: @username_6 Interesting, did not know uncertainty could still be useful. I'll include uncertainty in the next batch of major updates and do some research on the rest.  
> **username_5**: Just for reference https://github.com/astronexus/HYG-Database is a slightly larger list that includes fainter stars  

---

