Sources:
astrologyking.com/capulus-star/
www.constellationsofwords.com/capulus/
stellarium-web.org
en.wikipedia.org/wiki/Double_...
en.wikipedia.org/wiki/Messier...

I think the correct position of Capulus (the hilt) is Tau. 24°32′, but it is incorrectly called Messier 34 instead of Double Cluster by a lot of sources.

* Double Cluster has a magnitude of 3.7 and is visible with the naked eye, Messier 34 only 5.5 so hardly visible with the naked eye.

To me it looks like the confusion started because of different art styles of the Perseus constellation, one has a sword hand on top, the other just the head.
...

* Constellations of Words displays Capulus in the hilt, but calls it M34 (2nd image)
* Astrology King says "CAPULUS. A double cluster situated in the sword hand of Perseus" which is a clear indication that it's supposed to be the Double Cluster, but the image shows Messier 34.
...

The situation is a bit confusing:
* Most astrology pages refer to Capulus as Messier 34
* But it is also noted that Capulus is in the sword hilt at the top of Perseus
* Stellarium shows that the Double Cluster in the hilt on top (different artwork), and Messier 34 is above the shield (1st image)
...

Now the question is, what is the correct star cluster for the traditional name Capulus? Astrology King claims it should be Messier 34, but how is that verified?

(Aspectarian is certainly currently wrong in referring to Capulus as M34, while using the position of NGC869)

another star without a traditional name and the nomenclature name Messier 34:

,M34: Tau. 22°06′

Which means that in Swiss Ephemeris the star with the traditional name Capulus is the Double Cluster (en.wikipedia.org/wiki/Double_...), and not Messier 34 (de.wikipedia.org/wiki/Messier...).
...

Aspectarian (like most astrology software) is using Swiss Ephemeris by Astrodienst for all positions and calculations.

I just checked and there is indeed something funny. The star with the traditional name Capulus in Swiss Ephemeris is referring to:

Capulus,NGC869: Tau. 24°32′

But there is ...