<p>The USNO Sixth Catalog of Orbits of Visual Binary Stars (<a href="http://www.usno.navy.mil/USNO/astrometry/optical-IR-prod/wds/orb6" rel="nofollow">ORB6</a>)
has the orbital elements you need.</p>

<ol>
<li>$\gamma$ And is WDS 02039+4220</li>
<li>$\alpha$ Gem is WDS 07346+3153</li>
<li>$\zeta$ UMa is WDS 13239+5456</li>
</ol>

<p>Double star expert Bruce MacEvoy <a href="http://www.handprint.com/ASTRO/bineye3.html" rel="nofollow">explains</a> orbital elements in maybe enough detail to help you work out some state vectors.
My search also turned up a <a href="http://link.springer.com/chapter/10.1007/978-1-4614-3945-5_7" rel="nofollow">book chapter</a> by Andreas Alzner.</p>

CC BY-SA 3.0
2016-04-22T01:27:33.273Z
This is great! Thank you for finding both the information and places where I can read to actually *understand and use* the information! I've tried the CTIO [Multiple Star Catallog](http://www.ctio.noao.edu/~atokovin/stars/) as well as the [simbad](http://simbad.u-strasbg.fr/simbad/) portal linked in the comments below the question, but couldn't understand how to use what's there.
uhoh
CC BY-SA 3.0
2016-04-21T23:38:16.783Z
2016-04-21T23:38:16.783Z
Mike G
<p>I'd like to show a demonstration of Runge Kutta integration of real systems using examples of interesting multiple stars, where "interesting" means you can see through a small telescope that they are at least double. I've selected three:</p>

<ol>
<li>Gamma Andromedae (Almach)</li>
<li>Alpha Geminorum (Castor)</li>
<li>Zeta Ursae Majoris (Mizar and Alcor)</li>
</ol>

<p>How can I find a state vector (set of relative positions and velocities) - or something similar - for these multiple star systems? An open access link (for everyone) would be great, but a journal reference is fine as well if that's what it takes.</p>

<p>Of course the periods are long and there will be uncertainty - I'd just like to use whatever is known and available, for this demonstration.</p>

CC BY-SA 3.0
2016-03-18T12:01:44.600Z
http://simbad.u-strasbg.fr/simbad/sim-id?Ident=Gamma+Andromedae&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id   http://simbad.u-strasbg.fr/simbad/sim-id?Ident=Alpha+Geminorum&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id http://simbad.u-strasbg.fr/simbad/sim-id?Ident=Zeta+Ursae+Majoris+&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id and follow-up the measurements and references.
ProfRob
CC BY-SA 3.0
2016-03-18T13:48:16.147Z
Thanks @RobJeffries, honestly if I could decode those pages, I'd be smart enough to have known where to find them in the first place! I'm looking for an answer that shows me how to find *relative positions and velocities*, as will other stackexchange users in the future who find this question.
uhoh
<orbit><binary-star><orbital-elements>
State vectors of "interesting" multiple stars
uhoh
# State vectors of "interesting" multiple stars

(Asked by: username_0 on 2016-03-18)

I'd like to show a demonstration of Runge Kutta integration of real systems using examples of interesting multiple stars, where "interesting" means you can see through a small telescope that they are at least double. I've selected three:

1. Gamma Andromedae (Almach)
2. Alpha Geminorum (Castor)
3. Zeta Ursae Majoris (Mizar and Alcor)

How can I find a state vector (set of relative positions and velocities) - or something similar - for these multiple star systems? An open access link (for everyone) would be great, but a journal reference is fine as well if that's what it takes.

Of course the periods are long and there will be uncertainty - I'd just like to use whatever is known and available, for this demonstration.

**Tags:** orbit, binary-star, orbital-elements

> **Comments:**
> **username_1**: http://simbad.u-strasbg.fr/simbad/sim-id?Ident=Gamma+Andromedae&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id   http://simbad.u-strasbg.fr/simbad/sim-id?Ident=Alpha+Geminorum&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id http://simbad.u-strasbg.fr/simbad/sim-id?Ident=Zeta+Ursae+Majoris+&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id and follow-up the measurements and references.  
> **username_0**: Thanks @RobJeffries, honestly if I could decode those pages, I'd be smart enough to have known where to find them in the first place! I'm looking for an answer that shows me how to find *relative positions and velocities*, as will other stackexchange users in the future who find this question.  

---

## 1 answers

### Answer by username_2 on 2016-04-21. Score: 1 | Accepted answer

The USNO Sixth Catalog of Orbits of Visual Binary Stars ([ORB6](http://www.usno.navy.mil/USNO/astrometry/optical-IR-prod/wds/orb6))
has the orbital elements you need.

1. $\gamma$ And is WDS 02039+4220
2. $\alpha$ Gem is WDS 07346+3153
3. $\zeta$ UMa is WDS 13239+5456

Double star expert Bruce MacEvoy [explains](http://www.handprint.com/ASTRO/bineye3.html) orbital elements in maybe enough detail to help you work out some state vectors.
My search also turned up a [book chapter](http://link.springer.com/chapter/10.1007/978-1-4614-3945-5_7) by Andreas Alzner.

> **Comments:**
> **username_0**: This is great! Thank you for finding both the information and places where I can read to actually *understand and use* the information! I've tried the CTIO [Multiple Star Catallog](http://www.ctio.noao.edu/~atokovin/stars/) as well as the [simbad](http://simbad.u-strasbg.fr/simbad/) portal linked in the comments below the question, but couldn't understand how to use what's there.  

---

