This is the Dudley Observatory Skywatch Line for Wednesday, September 23rd and Thursday, September 24th written by Louis Suarato.
Autumn arrives in the Northern Hemisphere at 4:21 a.m. EDT Wednesday. This astronomical event, known as the Autumnal Equinox, occurs when the Earth’s celestial equator passes through the center of the Sun from north to south. It is during this time that the terminator is perpendicular to the equator and both hemispheres are equally illuminated. In our latitude, there will be 12 hours, 7 minutes and 51 seconds of daylight Wednesday. The Sun will rise due east and set due west on the day of the equinox.
After sunset, look for Saturn approximately 17 degrees above the southwestern horizon. The 77% illuminated, waxing gibbous Moon will be about 28 degrees above the south-southeastern horizon. Fomalhaut, also known as the Autumn Star, rises in the constellation Piscis Austrinus, at 8 p.m. above the southeastern horizon. Fomalhaut appears at its highest in September and remains above the southern horizon during the months of Autumn. It is the brightest star over that region in an area devoid of bright stars. Fomalhaut is 25.13 light-years away and shines at magnitude 1.15. Fomalhaut is the second brightest star as viewed from Earth, after Pollux, known to have a planetary system. Fomalhaut is a relatively young star estimated to be about 440 million years old. It is also a binary star with its companion star, Fomalhaut B, .91 light-years away from the main star.
Venus rises around 3:30 Thursday morning, followed by Mars a half hour later, and Jupiter at about 5:00. Leo’s brightest star, Regulus, and Mars will separated by less than a degree early Thursday and Friday mornings. Both Regulus and Mars will be 11 degrees to the lower left of Venus. Jupiter will be approximately 10 degrees to the lower left of Mars and Regulus.
Join the Dudley Observatory for the September 27th full lunar eclipse! On this night, the moon will pass through Earth’s shadow, making it appear blood red in the sky. The eclipse will occur from ~8:00pm to 1:30am the night of September 27th, with totality (full eclipse) occurring from ~10-11:30pm. miSci will be open (rain or shine) from 8-11:30pm with moon activities indoors and eclipse observing outdoors. Members of the Albany Area Amateur Astronomers group and Dudley Observatory Outreach Astronomer Valerie Rapson will be on hand with telescopes to help everyone enjoy the view. This is the last full lunar eclipse until 2018. You won’t want to miss it!
Moon activities and eclipse observing are free with museum admission. See misci.org/info for museum information.