Bob Moler's Ephemeris Blog

This is Ephemeris for Tuesday, August 26th. Today the Sun will be up for 13 hours and 31 minutes, setting at 8:29, and it will rise tomorrow at 6:59. The Moon, 3 days past new, will set at 9:44 this evening.

There is a star in the constellation of Corona Borealis, the Northern Crown, which astronomers are expecting to become a nova which means become rapidly very bright. The initial predictions favored last year, 2024, but it has yet to explode. The star’s designation is T Coronae Borealis, or T CrB for short. It’s a variable star designation. And an explosion occurs on one member of this binary star system about every 80 years. The last time was in 1946. Jean Schneider* of the Paris Observatory thinks they found a pattern within the 80-year time frame. The 227.6-day period of the white dwarf star orbiting its much larger primary. This seems to match the last three explosions. So the next likely date will be November 10th this year. We’ll see.

The astronomical event times given in this blog are for the Traverse City/Interlochen area of Michigan (Lat 44.7° N, Long 85.7° W; EDT, UT – 4 hours) unless stated otherwise. Times will be different for other locations.

* I found a link to this on the spaceweather.com website in a section called T CrB Nova Watch.

Addendum