<p>You're stuck. The very best parallaxes from Gaia lead to distance uncertainties of about 1 pc in the nearest clusters with nebulosity (Rho Oph would perhaps be the closest?).</p>
<p>About the best you can do is figure out whether stars are at the front or back. You do that by estimating a Bayesian distance from the parallax in an iterative way using the distribution of distances for all stars in the cluster as the prior probability distribution.</p>

CC BY-SA 4.0
2024-12-09T08:49:56.523Z
2024-12-09T08:49:56.523Z
ProfRob
<p>I am doing a project where I am trying to recreate a star cluster in 3D space using some cool retro™ neon Nixie tube indicators.</p>
<p>My first choice was LBN 1015, a nice group of stars with a small reflection nebula. But while the stars are within less than a parsec of each other from our perspective, their distances from us are uncertain by about 20 parsecs either way.</p>
<p>That’s annoying. Even the trapezium cluster has error in the radial direction far exceeding its size otherwise. As far as I can tell, simbad doesn’t have any feature to search for star clusters based on the average error in distance relative to the distance between its members, so I don’t know what to do here. Are there any examples that do have a well defined 3D shape?</p>

CC BY-SA 4.0
2024-12-08T10:55:57.303Z
This is probably a simple reflection of the difficulties in measuring the distance to stars (compared with the ease of measuring their direction with exquisite accuracy) I don't think that even the best measurements of distance (parallax) would be accurate enough even for nearby clusters (Pleiades).
James K
CC BY-SA 4.0
2024-12-08T12:02:27.563Z
A general question on 3D data from Gaia: https://astronomy.stackexchange.com/a/54281/16685 And the difficulty of getting accurate distance info for large bright objects, specifically Betelgeuse https://astronomy.stackexchange.com/q/36365/16685
PM 2Ring
CC BY-SA 4.0
2024-12-08T12:23:51.740Z
It's not that those stars will jitter by $\pm$20pc in any direction. In reality, those stars are often part of "moving groups" (googlable keyword), which are identified by precise velocity measurement. Then, if a clump of stars all have $\pm$20pc error, but are in a moving group, that means their real distances can be constrained more.
If you have a look in https://ui.adsabs.harvard.edu/abs/2017A%26A...608A..73K/abstract
(their Fig. 7), they identify a number of groups and clusters in the solar neighbourhood in velocity space. You could use those as starting point.
AtmosphericPrisonEscape
CC BY-SA 4.0
2024-12-09T02:58:02.603Z
@JamesK the Pleiades would actually work marginally well, because of how elongated it is in the radial axis. but indeed even it it does have a relatively large error in distance when compared to horizontal size. It seems I will probably have to settle with 2d, a shame.
Topcode
<distances><star-cluster>
Are there any star clusters associated with nebulae that have well defined 3D positioning of the stars in them?
Topcode
# Are there any star clusters associated with nebulae that have well defined 3D positioning of the stars in them?

(Asked by: username_0 on 2024-12-08)

I am doing a project where I am trying to recreate a star cluster in 3D space using some cool retro™ neon Nixie tube indicators.

My first choice was LBN 1015, a nice group of stars with a small reflection nebula. But while the stars are within less than a parsec of each other from our perspective, their distances from us are uncertain by about 20 parsecs either way.

That’s annoying. Even the trapezium cluster has error in the radial direction far exceeding its size otherwise. As far as I can tell, simbad doesn’t have any feature to search for star clusters based on the average error in distance relative to the distance between its members, so I don’t know what to do here. Are there any examples that do have a well defined 3D shape?

**Tags:** distances, star-cluster
> **Comments:**
> **username_1**: This is probably a simple reflection of the difficulties in measuring the distance to stars (compared with the ease of measuring their direction with exquisite accuracy) I don't think that even the best measurements of distance (parallax) would be accurate enough even for nearby clusters (Pleiades).  
> **username_2**: A general question on 3D data from Gaia: https://astronomy.stackexchange.com/a/54281/16685 And the difficulty of getting accurate distance info for large bright objects, specifically Betelgeuse https://astronomy.stackexchange.com/q/36365/16685  
> **username_3**: It's not that those stars will jitter by $\pm$20pc in any direction. In reality, those stars are often part of "moving groups" (googlable keyword), which are identified by precise velocity measurement. Then, if a clump of stars all have $\pm$20pc error, but are in a moving group, that means their real distances can be constrained more. If you have a look in https://ui.adsabs.harvard.edu/abs/2017A%26A...608A..73K/abstract (their Fig. 7), they identify a number of groups and clusters in the solar neighbourhood in velocity space. You could use those as starting point.  
> **username_0**: @JamesK the Pleiades would actually work marginally well, because of how elongated it is in the radial axis. but indeed even it it does have a relatively large error in distance when compared to horizontal size. It seems I will probably have to settle with 2d, a shame.  

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## 1 answers

### Answer by username_4 on 2024-12-09. Score: 0

You're stuck. The very best parallaxes from Gaia lead to distance uncertainties of about 1 pc in the nearest clusters with nebulosity (Rho Oph would perhaps be the closest?).

About the best you can do is figure out whether stars are at the front or back. You do that by estimating a Bayesian distance from the parallax in an iterative way using the distribution of distances for all stars in the cluster as the prior probability distribution.


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