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All you need to know: September equinox

2017’s September equinox arrives today. Happy autumn (or spring)!

Sun on the sky’s equator

Another great explanation of Friday’s equinox – plus beautiful graphics – from astronomer Guy Ottewell.

See it! Young moon and Jupiter

Wow! So many beautiful photos of something relatively hard to catch … the young moon returning to the evening sky this week next to the bright planet Jupiter.

How to see binocular comet C/2017 O1

Long-period comet C/2017 O1 – a visitor from the Oort Comet Cloud – is becoming visible in small telescopes and binoculars. This post includes charts that can help you find it.

Day and night exactly equal at equinoxes?

On the day of an equinox, the center of the sun would set about 12 hours after rising – given a level horizon, as at sea, and no atmospheric refraction.

Andromeda galaxy next door to Milky Way

The Andromeda galaxy is the closest spiral galaxy to our Milky Way and the most distant thing you can see with your eye alone. Find it in your night sky!

Another X-flare from the sun

We’re near solar minimum, but the sun has been active! Click here for a video of solar flares so far in September, 2017 and for news for the sun’s most recent X-flare.

How to see the Great Square of Pegasus

It’s easy! The Great Square of Pegasus consists of 4 stars of nearly equal brightness in a large square pattern. Once you find it, you can star-hop to other well-known sights in the sky.

Delta Cephei is a famous variable star

Delta Cephei doubles in brightness every 5.36 days and thereby helped establish the known distance scale of our galaxy and universe.

Giant sunspots, solar flares, aurora alert!

Sunwatchers are still tracking those 2 large sunspot groups making their way across the Earth-facing side of the sun. Then yesterday there was an X-flare! Watch for possible auroras.