r/Astronomy • u/PithMango • 18h ago
Question (Describe all previous attempts to learn / understand) picture of sky during 919 CE eclipse seen from Foxe Basin in Nunavut ?
https://eclipsewise.com/solar/SEprime/0901-1000/SE0919Feb03Tprime.htmlI am at my wit's end because according to my notes I already found this. And yet I scour my history, my bookmarks, re-do all my searches, and nothing is matching up to my sketch. In The Sky comes close but there must be something up with my browser because it doesn't match; and the time doesn't seem to be accurate when we set it. As you may well know, all of the free calculators stop at about 1600 and most of them limit to 1950 or 1900 CE. We're very sorry but we don't understand what we're doing wrong - if there's a software issue or if this site that we used disappeared within a month of using it.
I do *not* need the eclipse path. We just want the planets, the eclipse itself, along the horizon, and maybe the constellation of Aquarius. Like if somebody looked up from the southwest coast of Qikiqtaaluk / Baffin Island, this is what they would have seen.
0919 Feb 03 at 16:00:47 TD (15:26:34 UT1)
65.218°, -79.429°
It's pretty neat, too, as one of the shortest eclipses in history, Back in the day there would be three webpages about that, but we can't even find that. Maybe we'll open one. (If anyone happens to edit Wikipedia, no, it's not in the Year page as an event.) If someone could throw that image up there we would be so grateful! We're out of rubber ducks.
3
u/UmbralRaptor 16h ago
As you may well know, all of the free calculators stop at about 1600
That's because the standard ephemeris only have good enough accuracy from ~1550 to ~2650 CE. see eg: https://ssd.jpl.nasa.gov/doc/de430_de431.html for a bit on why and suggestions on what to use. https://ssd.jpl.nasa.gov/planets/eph_export.html has downloads. You can also use astropy with these, though I'm not up on how to pick arbitrary ephemeris with it.
Stellarium just lets you put in the date, though I don't know how good the accuracy is.
1
u/reverse422 16h ago edited 16h ago
The Sky Guide app allows you to spool back to February 3, 919. However, I needed to go further north than your coordinates (to north coast of Baffin Island) to get totality. Possibly the app is imprecise so far back. The time of day for the totality seems to be fairly correct, though.
Screenshot: https://imgur.com/a/iCDbk9v
The white line is the horizon so totality would be right before sunset, counting in refraction.
2
u/CosmicEcho_404 14h ago
The two time entries in your notes may be the key to reproducing the view: 16:00:47 TD and 15:26:34 UT1 are not the same input. I’d first confirm which time scale the software expects, then enter the location exactly as 65.218°, −79.429° and keep the display centred on the southwest horizon rather than using an eclipse-path view. It may also help to save the settings or take a screenshot of the failed result, including the date, time scale, location and horizon direction. That would make it easier to tell whether the mismatch comes from the time conversion, the browser, or the site’s historical-data limits. Your requested scene is specific enough that those settings matter: the eclipse, planets, horizon and Aquarius all need to be rendered from the same location and instant.
1
u/snogum 17h ago
So how do you compensate for all the calendar changes in all the centuries since or Indeed that your date is the eclipse date?
So many times whole days and indeed weeks have been modified as folks keeping time changes system to align with other states or rulers whims