{"id":788255,"date":"2024-09-03T11:23:52","date_gmt":"2024-09-03T16:23:52","guid":{"rendered":"http:\/\/spaceweekly.com\/?p=788255"},"modified":"2024-09-03T11:23:52","modified_gmt":"2024-09-03T16:23:52","slug":"catch-a-fall-feast-of-lunar-occultations-in-september","status":"publish","type":"post","link":"https:\/\/spaceweekly.com\/?p=788255","title":{"rendered":"Catch a Fall Feast of Lunar Occultations in September"},"content":{"rendered":"


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September offers a number of fascinating lunar occultation events worldwide.<\/em><\/p>\n

Chances are, there\u2019s one near you this month. The Moon is certainly busy in September, as its passage covers up (occults) multiple celestial objects worldwide. If skies are clear, you may just get a chance to see one of these events listed below, as the Moon blocks out a star, planet or star cluster.<\/p>\n

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You may well have seen images from last month\u2019s lunar occultation of Saturn from observers across the United Kingdom and western Europe. The Moon occults Saturn 10 times in 2024\u2014once for every lunation pass. The slowest moving of the naked eye planets, Saturn makes a good repeated target for the Moon. The rings are headed towards edge-on in 2025, making for an appealing view as it peeks out from behind the lunar limb.<\/p>\n

Why Occultations<\/h2>\n

Occultations occur in cycles, as the Moon journeys on its monthly trek five degrees above and below the ecliptic plane. In the current epoch, the Moon can occult four +1st<\/sup> magnitude stars: Aldebaran, Regulus, and (as is ongoing in 2024) Antares and Spica. The Moon moves its own diameter (30\u2019 or half a degree) once every hour, and the dark limb leads the way when it\u2019s waxing, and trails when it\u2019s waning. Dark limb ingresses can be especially dramatic.<\/p>\n

The Moon is also riding high in the sky in 2024, as we head towards a bi-decadal Major Lunar Standstill next year in 2025.<\/p>\n

An Occultation, Transit\u2026 or Eclipse?<\/h2>\n

Like eclipses, successive occultations in a cycle move westward by about 120 degrees of longitude. Lots of observational astronomy is no more than watching one thing pass in front of another, and seeing what happens: occultations, transits and eclipses are similar ways to express the what is essentially the same thing. Double star companions, profiles of asteroids, and diameters of tiny stellar sources have revealed themselves during occultations.<\/p>\n

Occultations in September<\/h2>\n

All exciting stuff, to be sure. Here\u2019s our rundown on what\u2019s in store for lunar occultations in September worldwide:<\/p>\n

First up, the 5% illuminated waxing crescent Moon occults Venus on September 5th<\/sup>, centered on 10:16 Universal Time (UT). Perhaps, only a few penguins and a few windswept remote research stations in Antarctica will witness to this daytime event. The rest of us will be treated to a very close pairing of the two at dusk.<\/p>\n

Looking westward at dusk on September 5th. Credit: Stellarium. <\/figcaption><\/figure>\n

Next, the 10% illuminated, waxing crescent occults the +1st<\/sup> magnitude star Spica (Alpha Virginis) for central Africa on the evening of September 6th<\/sup> centered on 17:04 UT. Fun fact: located 250 light-years distant, Spica is a close candidate (along with Betelgeuse) for a nearby galactic supernova.<\/p>\n

\"Spica\"
The visibility footprint for the Spica occultation on September 6th. Credit: Occult 4.1.<\/figcaption><\/figure>\n

Four days later on September 10th<\/sup>, the 43% illuminated, waxing crescent Moon occults the +1st<\/sup> magnitude star Antares (Alpha Scorpii) for western Australia centered on 13:09 UT. We caught a similar event back in 2009.<\/p>\n