Stellarium Target Distances

[Grifflin]

Hi All

Has anyone noticed that in some cases, the distance to targets selected in Stellarium don't seem to agree with other sources?  ....or the other way round!  ....and I'm talking differences outside of the "error bar".

For example, the Heart Nebula (IC 1805) is quoted as aprox 2,500 ly in Stellarium but in Wikipedia it is aprox 7,500 ly.   Also, if you look at the Christmas Tree Cluster (NGC 2264), Stellarium has that at about 1,200 ly but Wikipedia at 2,350 ly.

Is it just me?

 

Neil

[vlaiv]

That is quite possible.

Stellarium simply uses catalogs of celestial bodies and if that catalog lists particular item at certain distance - that is what you'll get.

For some bodies it is not easy to determine actual distance, and there might be corrections for previous surveys. For example - if you try to measure distance to certain Ha region with associated cluster - you'll use distance to stars in that cluster. Maybe parallax measurements for those stars has been off in previous survey and newest survey gives different values.

Interestingly Fish Head nebula (part of Heart nebula) is listed to be

5545 Ly

I'd go by wiki in this case, but you can also go to Simbad and look at more recent surveys like Gaia2 - for some of the stars in cluster to determine their parallax and hence distance.

[ONIKKINEN]

Stellarium measurements can be missing completely or outdated as new data comes in. Gaia is working hard on rewriting many distance measurement so these things can change quite a bit.

When i try looking up distances to galaxies in my shots i often have to resort to NED: NASA extragalactic database for any information of the target. For instance NGC 2614, a galaxy in Camelopardalis has no distance info on Stellarium or Simbad, but has one in NED: http://ned.ipac.caltech.edu/byname?objname=NGC+2614&hconst=67.8&omegam=0.308&omegav=0.692&wmap=4&corr_z=1

[Grifflin]

Thanks Both....yep, looks like there is a fair variation of distance data out there.  I looked up IC 1805 on Simbad and there are four measurements: three in the range 1.7 kpc to 2 kpc and a fourth at about 6.1 kpc.  So about 5,500 to 6.500 ly if you ignore the fourth one.

I think the learning here for me is double check distance measurements in Stellarium before quoting them  

Neil

Edited December 4, 2021 by Grifflin