Looks like the link I had to that French Sirius calculator has died. Dang it! So I’ve looked around and have something to offer as a substitute. It’s not as easy to interpret, but here’s what we’ve got:
Once you go to the site, input the latitude of your location or the location for which you want to know the heliacal rising. Then enter a date…probably sometime in July or August. Note that the farther north your latitude, the later Sirius rises.
Then look at the timeline below the animation. Look for the blue “star above horizon” line. As you change the date with the red slider (upper right), you’ll see that line move. You’ll also see the darkness-to-light transition on the timeline. You will probably be able to see the star more easily about an hour before dawn. So set the red line in the timeline at about an hour before dawn (dawn is where the grey turns to yellow in the timeline).
Keep messing with the date until you see the “star above horizon” blue line at about an hour before dawn. If you have a perfectly clear morning—and all the Goddesses and Gods are willing—that’s when you might be able to see Sirius rise in your area. Or it could be a couple of days later when you’ll actually be able to observe it with your naked, non-mathematical eyeballs.
Celebrating Isis’ birthday on any of the dates around the rise of Sirius in your area will please the Goddess just fine. Luckily for me, August 17-18 is the mathematical rising in my area, but I probably wouldn’t be able to see it until the 20 or so. But since the mathematical date is near a weekend…I will probably celebrate Her birthday on the 18th or 19th—and that will be well within bounds.
See what you figure out for your area…and have a happy Isis’ birthday!
Isiopolis 
Knowing I will sound like a complete ignoramus here, but where did you learn the connection between Sirius rise and her birthday? Is it written somewhere?
No, you don’t sound like an ignoramus and yes, there is written evidence. The ancient Egyptians timed their New Year by the rising of Sirius…and we have calendars from Egypt, in particular one called the Cairo Calendar, that has the birthdays of some key Deities on the first through the fifth after the New Year. Osiris on the 1st day, Horus the Elder on the 2nd, Set on the 3rd, Isis on the 4th, and Nephthys on the 5th. When you could have seen Sirius rise depended on where you were in Egypt. The farther south, the sooner you’d see it. So Isis’ temple at Philae would have observed it sooner; at Isiopolis, a bit later. In addition, the star Sirius (Sopdet in Egyptian) itself has long been associated with the ba or soul of Isis, so you could celebrate the rise of Her soul on the actual date of the rise of Sirius and Her birthday on the fourth day after that.
Pretend I capitalized Her in the previous post.
Thank you so much for this! I’ve been looking for a way to find this out online and had come up empty. I can’t wait to celebrate Her birthday!
For me, Sirius rose on the 1st of July, for the north coast of Egypt it’s around the 9th of August….hey that’s exactly one year after I got my driver’s licence! 😛 …anyways, happy birthday Isis! ❤ ❤ ❤
I know this is a bit later on but thought id add my tuppence worth anyway 🙂 I live in Scotland and at 8pm first week of February Sirius is south traveling west. It changes colour to white , red, blue. Im assuming it is Sirius by what i have read about it. Can someone tell me if it is Sirius ? Its the only star that is so bright and beautiful. By June i cant see it anymore and it always comes into view in /February. I would welcome any information on this Thanks.
Hi, Alma! You can find Sirius by the Orion constellation. It’s pretty easy to find. This post might help: https://isiopolis.com/2014/07/27/isis-sirius-rising/ I also love having a star finder app on my smartphone. You just point it at the sky and it tells you what you’re seeing.
awesome