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[Chicago Astronomer - Astro Joe]

Bright Star to slip behind the Moon

13 July 2024

In a rare event, the bright star Spica will slide behind the Waxing 1/4 Moon on Saturday evening the 13th of July 2024...and if clear, would be a great event to observe in optical equipment.

Normally, the Moon passes in front of stars all the time, but usually they are very faint, but Spica is one of the brightest stars in the night sky at a magnitude of about 1.4 and at 250 +/- light years away. The Moon, at only 250,000 miles away will cover Spica or "Occult" the star from right to left.

 

The Moon will be well situated high to the Southwest and Chicago sky lovers will be in a nice position to enjoy this event.

Start your observation session at about 10:00 PM and train your telescopes or binoculars at the Moon/Spica pair. Spica will disappear on the dark of the half-lit Moon at about 10:10 pm and emerge along the lit side at 11:22 pm.  As Spica slides behind the Moon, you may notice the star flicker as it passes behind lunar mountains and surface irregularities.

Any size telescope or binoculars will allow you to share in the Occultation event.

Astro Joe 

[Centaur]

Jul 4, 2024 14:57:49 GMT -6 Chicago Astronomer - Astro Joe said:

Bright Star to slip behind the Moon

13 July 2024

In a rare event, the bright star Spica will slide behind the Waxing 1/4 Moon on Saturday evening the 13th of July 2024...and if clear, would be a great event to observe in optical equipment.

Normally, the Moon passes in front of stars all the time, but usually they are very faint, but Spica is one of the brightest stars in the night sky at a magnitude of about 1.4 and at 250 +/- light years away. The Moon, at only 250,000 miles away will cover Spica or "Occult" the star from right to left.

The Moon will be well situated high to the Southwest and Chicago sky lovers will be in a nice position to enjoy this event.

Start your observation session at about 10:00 PM and train your telescopes or binoculars at the Moon/Spica pair. Spica will disappear on the dark of the half-lit Moon at about 10:10 pm and emerge along the lit side at 11:22 pm.  As Spica slides behind the Moon, you may notice the star flicker as it passes behind lunar mountains and surface irregularities.

Any size telescope or binoculars will allow you to share in the Occultation event.

Astro Joe 

Joe, I was holding off on a similar announcement until closer to the event. But you beat me to it, so kudos to you. 

It will appear slightly wider than a waxing Half Moon, since it will have just entered the second quarter of its lunation. 
The Moon is always in one of the four quarters of a lunation, and what's listed as FQ on calendars is the cusp marking the completion of the first quarter and the commencement of the second quarter. As noted by Jean Meeus, a more proper term is eastern quadrature, i.e. 90 degrees east of the Sun geocentrically. An average of 17 minutes before that time the Moon displays geocentric dichotomy, i.e. a 50% illuminated Half Moon. Beware, some authors get these confused.

Spica is currently undergoing a series of 20 monthly occultations from 2024 JUN 16 to 2025 NOV 17. In addition to the one this month, Chicagolanders will be able to view a daytime occultation of Spica on 2024 SEP 06 and one predawn 2024 NOV 27. This autumn my website will display three charts for that latter one.

My three graphics related to this month's Spica occultation can be found at www.CurtRenz.com/occultations.html where they have been available for some time. 

[Centaur]

Spica Occultation Series:

[Chicago Astronomer - Astro Joe]

Very hazy in Chicago.

Moon is visible, but nothing else.

A no-go for me.

[Centaur]

Jul 13, 2024 21:10:46 GMT -6 Chicago Astronomer - Astro Joe said:

Very hazy in Chicago.

Moon is visible, but nothing else.

A no-go for me.

Too bad, Joe. But nice that you tried to get others enthused. Rain here in Florida. Perhaps some others had better luck and will report to this thread.
You'll have another shot with Spica and the Moon on November 27th. Before that, you can watch the Moon occult the Pleiades on November 16th.