{"id":2935,"date":"2023-08-24T13:49:41","date_gmt":"2023-08-24T13:49:41","guid":{"rendered":"https:\/\/www.woas-fm.org\/?p=2935"},"modified":"2023-08-24T13:52:25","modified_gmt":"2023-08-24T13:52:25","slug":"astrocal-september-2023","status":"publish","type":"post","link":"https:\/\/www.woas-fm.org\/?p=2935","title":{"rendered":"AstroCal &#8211; September 2023"},"content":{"rendered":"<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0\u00a0Start your observations for September in the eastern sky in the hours before sunrise.\u00a0 <\/span><b>Venus<\/b><span style=\"font-weight: 400;\"> and <\/span><b>Jupiter<\/b><span style=\"font-weight: 400;\"> will be easy to find shining at -4.8 and -2.5, respectively.\u00a0 They will be the brightest objects in the sky not counting the <\/span><b>Full Moon<\/b><span style=\"font-weight: 400;\"> and the <\/span><b>Sun.\u00a0 <\/b><span style=\"font-weight: 400;\">Venus will be due east in the lower part of <\/span><b>Gemini &#8211; the Twins<\/b><span style=\"font-weight: 400;\"> while Jupiter will reside to the right of the <\/span><b>Pleiades star cluster<\/b><span style=\"font-weight: 400;\"> located in the shoulder of <\/span><b>Taurus &#8211; the Bull.\u00a0 <\/b><span style=\"font-weight: 400;\">During the course of the month, the crescent of Venus as seen from <\/span><b>Earth <\/b><span style=\"font-weight: 400;\">will increase from a slim 13 percent to 36 percent by the end of September which will increase its brightness even more.\u00a0\u00a0<\/span><\/p>\n<p><b>\u00a0\u00a0\u00a0\u00a0\u00a0Mercury<\/b><span style=\"font-weight: 400;\"> reaches inferior conjunction (where it will be directly between Earth and the Sun) on September 6.\u00a0 When it emerges about a week later, it will be near the horizon just below and to the left of Venus.\u00a0 Your observing challenge for the month is to find the earliest day you can spot the <\/span><b>Winged Messenger <\/b><span style=\"font-weight: 400;\">when it makes its appearance in the morning sky.\u00a0 Mercury will be easier to spot as it reaches its greatest elongation from the Sun (about 18 degrees on September 22).\u00a0 It will appear 51 percent illuminated with its greatest brightness reaching -0.3.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0\u00a0<\/span><b>Saturn<\/b><span style=\"font-weight: 400;\"> will be the easiest evening planet to find in the SE sky two hours after sunset.\u00a0 Located between <\/span><b>Aquarius, the Water Bearer <\/b><span style=\"font-weight: 400;\">and <\/span><b>Capricornus, the Sea Goat<\/b><span style=\"font-weight: 400;\">, Saturn will continue in retrograde motion until November 2023.\u00a0 During retrograde motion, the planet will appear to be moving east to west among the background stars.\u00a0 When Saturn reached opposition in late August<\/span><b>, <\/b><span style=\"font-weight: 400;\">it was 73 light-minutes from us (or 8.8 astronomical units) with a magnitude of 0.4.\u00a0 In September, the <\/span><b>Ringed Planet <\/b><span style=\"font-weight: 400;\">will appear as a bright oval-shaped disk when viewed with binoculars but one will need a small backyard telescope to see the rings which will be tilted at 10 degrees relative to the Earth.\u00a0 One can see why first attempts to view the planet with early telescopes (which would have been fuzzier images compared to modern telescopes) led some to say the planet looked to have \u2018ears\u2019.\u00a0 Mars will be difficult to see low in the western sky as it nears conjunction with the Sun.\u00a0 It will be lost in the Sun\u2019s glare in November and re-emerge in the morning sky early in 2024.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0\u00a0The August <\/span><b>Blue Moon<\/b><span style=\"font-weight: 400;\"> (the second <\/span><b>Full Moon<\/b><span style=\"font-weight: 400;\"> in a calendar month) took place on the 30th.\u00a0 This means the Lunar phases in the early part of September will be a waning cycle ending with an old <\/span><b>Crescent Moon <\/b><span style=\"font-weight: 400;\">that will pass Venus and Mercury in the morning sky Sept 11-13.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">The <\/span><b>New Moon <\/b><span style=\"font-weight: 400;\">takes place on Sept 14, so you can look for the <\/span><b>Young Crescent Moon <\/b><span style=\"font-weight: 400;\">low in the western sky an hour after sunset a couple of days later.\u00a0 The <\/span><b>First Quarter <\/b><span style=\"font-weight: 400;\">(9-22), and <\/span><b>Full Moon <\/b><span style=\"font-weight: 400;\">(9-29) will follow.\u00a0 The center of the <\/span><b>Milky Way galaxy<\/b><span style=\"font-weight: 400;\"> can be located on 9-22 as the First Quarter Moon crosses the <\/span><b>Tea Pot Asterism <\/b><span style=\"font-weight: 400;\">in <\/span><b>Sagittarius, the Archer.<\/b><span style=\"font-weight: 400;\">\u00a0 There is too much distance and interstellar material between us and our galactic center to actually see it, but if you want to travel there in a flight of imagination, that is the direction you will need to go.\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0Sept 23 will also mark the <\/span><b>Autumnal Equinox <\/b><span style=\"font-weight: 400;\">when the Sun\u2019s vertical ray crosses the Equator at 2:50 a.m. EDT.\u00a0 The Equinox marks the official start of Fall in the Northern Hemisphere.\u00a0 All locations on the planet will experience 12 hours of daylight and 12 hours of darkness at this time.\u00a0 This places us three months past the longest daylight period and three months closer to the shortest daylight (and thus, the longest night) of the year.\u00a0\u00a0\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0This month\u2019s historical item honors lawyer and amateur astronomer Johann Bayer (1572-1625) who lived in Augsburg, Germany.\u00a0 In September 1603, he first published <\/span><i><span style=\"font-weight: 400;\">Uranometria<\/span><\/i><span style=\"font-weight: 400;\">, a book featuring 51 copper-plate engravings covering both the northern and southern celestial hemispheres.\u00a0 These star maps were drawn using a trapezoidal projection where the longitude and latitude are projected as straight lines, with lines of constant declination remaining parallel, but lines of constant right ascension converging at the poles.\u00a0 On the back of each map was a corresponding catalog of stars.\u00a0 This work became the standard reference for astronomers throughout the 17th and 18th century. (Historical information provided by Jason Ybarra for the <\/span><i><span style=\"font-weight: 400;\">American Astronomical Society Historical Astronomy Division<\/span><\/i><span style=\"font-weight: 400;\">).\u00a0\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0\u00a0<\/span><span style=\"font-weight: 400;\">Compiled by Ken Raisanen of WOAS-FM &#8211; information provided by <\/span><i><span style=\"font-weight: 400;\">Abrams Planetarium Sky Calendar<\/span><\/i><span style=\"font-weight: 400;\">, Michigan State University.\u00a0 More information and subscription information can be found on their website at <\/span><a href=\"http:\/\/abramsplanetarium.org\/\"><span style=\"font-weight: 400;\">http:\/\/abramsplanetarium.org\/<\/span><\/a><span style=\"font-weight: 400;\">skycalendar\/ or on Twitter at <\/span><a href=\"http:\/\/twitter.com\/AbramsSkyNotes\"><span style=\"font-weight: 400;\">http:\/\/twitter.com\/AbramsSkyNotes<\/span><\/a><span style=\"font-weight: 400;\">.\u00a0 Yearly subscriptions cost $12 and can be started anytime.<\/span><\/p>\n<p>&nbsp;<\/p>\n<p>Top Piece Video:\u00a0 Earth, Wind and Fire &#8211;\u00a0<em>Shining Star\u00a0<\/em>live on\u00a0<em>The Midnight Special<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"<p class=\"excerpt\">&nbsp; \u00a0\u00a0\u00a0\u00a0\u00a0Start your observations for September in the eastern sky in the hours before sunrise.\u00a0 Venus and Jupiter will be easy to find shining at -4.8 and -2.5, respectively.\u00a0 They will be the brightest objects in the sky not counting the Full Moon and the Sun.\u00a0 Venus will be due east in the lower part [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[11,8,9],"tags":[],"class_list":["post-2935","post","type-post","status-publish","format-standard","hentry","category-education","category-from-the-vaults","category-woas"],"_links":{"self":[{"href":"https:\/\/www.woas-fm.org\/index.php?rest_route=\/wp\/v2\/posts\/2935","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.woas-fm.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.woas-fm.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.woas-fm.org\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.woas-fm.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2935"}],"version-history":[{"count":3,"href":"https:\/\/www.woas-fm.org\/index.php?rest_route=\/wp\/v2\/posts\/2935\/revisions"}],"predecessor-version":[{"id":2938,"href":"https:\/\/www.woas-fm.org\/index.php?rest_route=\/wp\/v2\/posts\/2935\/revisions\/2938"}],"wp:attachment":[{"href":"https:\/\/www.woas-fm.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2935"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.woas-fm.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2935"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.woas-fm.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2935"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}