Watch the star Porrima hide behind the Moon Friday evening

There will be a nice “prime time” lunar occultation of ZC1821, Porrima, in Virgo Friday evening June 30 (July 01 UT)

An occultation occurs whenever one celestial body disappears behind another. This is commonly a star disappearing behind the moon but also when a star disappears behind a body like an asteroid.

Finding the star should be easy, it is the magnitude 3.4 star easily spotted naked eye that will be positioned just east (left) of the Moon at 10 PM EDT Friday evening.

Use the finder maps below I created using Stellarium

Porrima Occultation A 1 Jul 17

Begin your observing session looking to the southwest. Enjoy the view of Spica, (a Vir), Jupiter, Porrima and the Moon east to west (left- right) across the southern sky.

The Moon and Porrima will be about 5 degrees (half a closed fist held at arm’s length) west (right) of Jupiter

The occultation will happen in daylight for those in the Pacific Time zone, twilight if you’re on Mountain time, near dusk in the Central zone and late twilight-dark in the Eastern U.S. and Canada

Porrima Occultation B 1 Jul 17

The star will disappear behind the Moon’s dark limb and reappear about an hour later on the sunlit eastern limb of Luna.

Predictions for those of us here in southern Indiana call for disappearance at 10:46:39 PM, reappearance at 11:51:16 PM.

Find IOTA predicted disappearance and reappearance times for hundreds of communities IOTA OCCULATION ZC1821.