Welcome to the Cosmic Calendar!
This is a space for astronomy that looks into the night sky as a living language of rhythms and presences. "How big, how far, how fast, how much"… is just the beginning. We give astronomical facts meaning so we can better understand life above and between us.
Week of January 25-31: ARCTURUS
The Winter Sky: Bootes & Arcturus
I like to look at the sky early in the morning in winter. 5:00 am is a perfect time. It's a very different sky then let's say 10:00 p.m., having moved through almost a third of the whole celestial sphere. You're looking at a totally different set of constellations... and I love how quiet it is, with an occasional screech owl sounding in the background.
Today is January 25th, 2026 in St Petersburg, Florida and Arcturus peaked over the east-northeast horizon around 3:00 am-several hours before dawn. (You can also see it just after sunset for an hour before it dips under the west-northwest horizon). Arcturus is just emerging from its "invisible period" when it stays above the horizon in full sunlight through the holiday season (stars hide in daylight). Once springtime comes, it will be a brilliant night star once again reigning high above.
Arcturus: Guardian of the Bear
It's 5:30 am now at about 28 degrees northern latitude, and Arcturus is already climbing up. 'Arcturus' in Greek (Αρκτούρος) means 'guardian of the bear' or "bear watcher," derived from arktos (bear) and ouros (watcher/guardian). It refers to its position in the sky since it follows the Great Bear (or Big Dipper) around the celestial pole. According to ancient traditions, it was also called 'Atlas' because it is near the Pole Star and seems to support the sky with one outstretched arm if you consider its place within the whole constellation of Boötes.
Egyptians called Arcturus a 'mooring post'. In Arabic, 'Arcturus' is called 'Haris-el-sima' (Keeper of Heaven). It is the 4th brightest star in the sky and the brightest star in the northern celestial hemisphere.
— Sabrina Dalla Valle, Senior Cosmic Analyst