Holger Isenberg Wrote:
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> Searching around for the definition of Hathor’s
> birthday only turned up the Sirius helical rising
> day for me. Can you point me to this 10 day before
> definition or other definitions?

Hagar, Stansbury. "What was the star of Bethlehem." Popular Astronomy 26 (1918): 229. found at [adsabs.harvard.edu]

I did find other dates, yes, including the rising of Sirius.

> Temples in ancient Europe are inded almost
> exclusively aligned to certain Sun rise/set
> locations, mostly solstices as the equinoxs are
> more difficult to determine without high precision
> gear. The solstices are relatively easy as there
> the sun rise/set location changes direction of its
> movement between each day.

Yes. And it was fairly easy for the Egyptians to align temples. At Abu Simbel, the temple of Ramesses II is aligned so that the sun shines on his face on the date of his birth and on the date of the beginning of the harvest season: [egyptindependent.com]

>
> The helicacal rising is also easy to determine if
> you have that constant clear sky weather as in
> Egypt. As before the star is just not visible in
> the morning and then suddenly appear for the first
> time.
>
> The sun alignment for sunrise at a day between the
> solstices is extremely difficult to determine
> without high precision gear.

It's very easy. You go outside, wait until sunrise (or sunset), place a staff onto the ground at the location you want, and begin stretching the cord along the shadow. You'll get a perfectly straight line, aligned to the sun at that date. See Temple of Ramesses, above.

The "stretching of the cord" is right there in the heavens, with Twaret measuring the heavens shown among the stars on Dendera ceiling.

There is nothing in the plan of the temple that indicates it was an observatory for watching for the rising of Sirius... and in fact, none of the openings are pointing towards the spot where Sirius would rise... as you can see from the floor plan here (note that North is the bottom of the diagram): [upload.wikimedia.org]

There are some temples with stellar alignments and the Egyptians adjusted these as the position of the stars changed (Lockyer, cited here on this NASA page) [sunearthday.nasa.gov]

-- Byrd
Moderator, Hall of Ma'at