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Hi
Grazie. Molto impressionante.
Regards.
Hi
It is interesting to me that although Arcturus is more than four times farther away from us than Sirius, it has moved about 18.5° in the sky in that time of about 30,000 years. Whereas Sirius only moves “only” about 11°. To me, this means that in the distant past, Arcturus must have been so far away from us that it could not be seen by the eye, and the same is true in the future when it is so far away from us that it is no longer visible. So I think that Arcturus is just passing by us and not part of our neighboring stars.
Regards
Hi
The extragalactic origin of the Arcturus group was the subject of a paper published in 2004
https://iopscience.iop.org/article/10.1086/381751 (open access) and an other one in 2019
https://www.aanda.org/articles/aa/abs/2019/11/aa35234-19/aa35234-19.html (open access).
Hopefully GAIA will let us know more.
Regards.
Hi, Bercu.
Thanks for the links and I’ll check it out right away.
Regards
Thanks BERCU, just added to the External Link Page.
Also added this interesting article:
New constraints on ΔT prior the second century AD – (Guillermo Gonzales 2018)
ABSTRACT
Ancient lunar appulse and occultation observations are analysed to derive new constraints on the difference between Terrestrial Time and Universal Time (ΔT). The new estimates are combined with literature values to produce an updated equation for calculating ΔT prior to the second century AD.
Con la versione 1.0.78 sembra tutto ok. Il moto proprio di Sirio e Arturo, già noto in epoche più recenti di quelle qui descritte, sarà di aiuto per ulteriori ricerche di archeoastronomia. Grazie
Saluti