Updated August 15, 2019
The Moon was full this morning at 8:29 am and was in the dim constellation Capricornus. Tonight it will cross over into Aquarius. It will rise later and later in the evening as the days progress, coming up just after sunset tonight and about an hour later each night. The Sun is setting earlier and earlier each evening, enough to be noticeable after a few days to a week. We at mid-northern latitudes are experiencing daylight shrinking by two minutes per day (longer at higher latitude). Further north the nights are starting to get cooler (not so in the Houston, Texas area) as the northern hemisphere summer begins to wind down. Last week saw the mid-point of astronomical summer, the moment halfway between the June solstice and the September equinox. To be exact, this moment occurred at 6:52 am CDT (11:52 UT) on 7 August.
Bright Jupiter is the first to become visible low in the southern sky as night falls. Through steadily held binoculars the planet resolves into a tiny disk, accompanied by two, three, or four tiny “stars”. These “stars” are the Galilean moons of Jupiter, each similar in size or a bit larger than our own Moon. Small telescopes show these moons more clearly. Saturn becomes visible just as the brighter stars become visible. Saturn is low in the Southeast as it gets dark.
The Big Dipper is now fairly low in the Northwest, appearing diagonally situated as night falls, and going through a scooping motion as the evening progresses. The end stars of the bowl of the Dipper point upward to Polaris, the North Star, and also marker of the end of the handle of the Little Dipper. Unlike the Big Dipper, most of the stars of the Little Dipper are difficult to see unless viewed in a dark, moonless sky. At Polaris’s upper left are the end stars of the bowl of the Little Dipper. They are sometimes called the Guardians of the Pole, since they always circle around Polaris, day and night, all year long. Extend the curve or arc of the handle of the Big Dipper to the left to “arc to Arcturus”, which is relatively high in the west at night fall. Below and to the left, “speed on to Spica” to find the brightest star of Virgo, low in the southwest.
Vega sits high in the eastern sky, almost overhead, at nightfall, passing close to (or through, depending on your northern latitude) the zenith around 10 pm local time. Deneb follows about two hours later. After nightfall, the third member of the Summer Triangle, Altair, shines high in the southeast. Above and to the left of it, by the width of a finger held at arm’s length, is fainter Tarazed. Look at the two through binoculars to see their contrasting colors: Altair appears a cool shade of white while Tarazed appears orange in color. Look a little more than the width of a fist held at arm’s length to the left or lower left to find a diamond-shaped pattern (with a tail pointing downward), the constellation Delphinus the Dolphin. Roughly midway between Altair and Delphinus is a smaller constellation, Sagitta the arrow, which appears to point downward.
Late in the evening, the constellations of Northern Hemisphere Autumn are making their appearances, beginning with the “W” (or “M”) shaped Cassiopeia, which is getting higher in the northeast as the days pass. As Cassiopeia ascends, the Great Square of Pegasus sits on one corner in the eastern sky. The waning gibbous Moon rises below it late in the evening of August 16. From the left corner of the Square the constellation Andromeda emerges, marked by 3 stars including the star that joins the two constellations at the corner of the square. These are the first of the autumn constellations that are starting to appear in the eastern skies late these late summer evenings. These lead a procession of fall constellations that rise in turn as the night progresses, culminating in a predawn display of some of the more prominent winter constellations: Auriga, Taurus, and Orion.
Mercury is visible in early dawn low in the East-Northeast, brightening from magnitude -0.2 to -0.8. Binoculars and a clear horizon will help to find the planet below and to the right of the easier-to-spot twins, Pollux and Castor. The three formed an almost straight line on the morning of the 10th of August. Mars and Venus remain hidden from view until October.
The summer sky is host to a number of beautiful deep-sky objects. A sampling of these was imaged July 28 with the 16-inch and SBIG STT 1603-ME camera. Images and descriptions of these objects can be found at http://www.pvamu.edu/pvso/cosmic-corner/project-summary-2/. Another observing session happened the evening of August 13. A few objects were imaged and presented at the website above. We have an instrument package that consists of an SBIG STf 8300M camera, a filter wheel with filters, and an autoguiding telescope. The “pro package” as it is called should integrate into the setup relatively seamlessly and will enable the production of color imagery. As the project continues to develop, improved images will be posted, along with progress updates, at that location.
Also in the predawn skies are the planets Neptune and Uranus are visible but they need optical aid and finder charts to find. Uranus glows at magnitude 5.8 and is high in the southeast before the start of dawn. Neptune glows fainter at 7.8 and is high in the south southeast at dawn. In fact, it rises late in the evening. Click here for the story behind their discovery, how to observe each planet, and a link to the finder chart for each planet for this year.
Go to https://www.skyandtelescope.com/observing/sky-at-a-glance/this-weeks-sky-at-a-glance-august-9-17/ where you will find the current “Sky at a Glance” (currently for the week ending August 3). There are lots of links to interesting news stories and additional observing projects for those who are interested. Last January’s total lunar eclipse featured a meteor impact flash seen and imaged widely. This event took place just as totality was getting started. One of the many imagers, Nicolas Lefaudeux, posted his images to his website. These images feature realistic views of recent total lunar eclipses as well as the meteor impact flash and other types of images. A nice montage of the total lunar eclipse was assembled by Doug Holland, it can be viewed at this website.
The Prairie View Observatory complex is almost complete and we are currently working to bring the telescopes on line. The PVO complex has 3 domes, including the existing Solar Observatory, and two new domes. For updates on this progress check out https://www.pvamu.edu/pvso/cosmic-corner/project-summary-2/. Also, more information and images can be viewed at https://sites.google.com/view/saganti-astro/home. The two new domes contain our Meade 16-inch advanced telescope (east dome, an Astrohaven clamshell style dome) and a new 0.6 meter (24-inch) PlaneWave Corrected Dall-Kirkham telescope (west dome, an Ash dome). The design features these two domes situated east and west of a visitor’s center, which is immediately north of the existing Solar Observatory. First light for the new observatory is expected later this summer. Keep checking back for updates.
Juno, the spacecraft, continues to send back spectacular images. You can find them at https://earthsky.org/space/juno-spacecraft-image-nov-2018-eichstadt-doran and https://www.missionjuno.swri.edu/junocam/processing?ob_from=&ob_to=&phases%5B%5D=PERIJOVE+15&perpage=16. Juno has been approved to continue orbiting Jupiter until at least July 2021. For more information about this mission in general visit www.nasa.gov/juno. You can also visit http://www.cnn.com/2016/06/30/health/juno-jupiter/index.html which has some additional interesting facts about the mission.