What’s Up?

Updated June 27, 2019

We are now one week past the June Solstice, the first day of summer in the Northern Hemisphere. We have already passed the date of earliest sunrise which occurred on June 14 for locations near 40 degrees north latitude. Earliest sunrise precedes the Solstice by as much as two weeks for locations the latitude of Hawaii (around 20 degrees north), and happens closer to the actual solstice date the further north one goes. The maximum amount of actual sunlight occurs on June 21, then the latest sunset happens one to two weeks later, depending on latitude. For some we are at or near the time of latest sunset. More information on this, including a link to almanacs that you can use to find sunrise / sunset times for your location, can be obtained at this website.

Mercury and Mars continue to linger in the evening sky though they are difficult to see without binoculars and a clear west-northwestern horizon. They form roughly a straight line with Pollux and Castor, low in the bright twilight 30 minutes after sunset. Mars glows at magnitude +1.8 and Mercury is +0.8. Pollux and Castor are similarly bright, at +1.2 and +1.8, respectively. High above this is the Big Dipper, which hangs down by its handle as the twilight fades and the stars come out. Its curved handle arcs toward Arcturus which is high in the south at nightfall. The end stars of the bowl of the Big Dipper point to Polaris, the North Star. Extending up from there is the rest of the Little Dipper. The two end stars, Pherkad and Kochab, are easy to see, but the remaining four stars require a fairly dark sky to see them.

As the sky darkens, Leo the Lion becomes visible low in the west, starting with its brightest stars. Regulus is the lowest star of the constellation; extending up and to the right is the Sickle of Leo, shaped like a backwards question mark. The rest of the constellation extends almost 30-degrees, or three fist-widths (with the fist held at arm’s length) above and to the left. The star Denebola marks the tail end of this constellation. Leo continues to drop lower and lower with each passing evening until it fades into the sunset glow sometime late next month. The Coma Bernices star cluster is visible to the naked eye above Leo as seen from darker skies (this used to be considered part of Leo, the fuzz of his tail). To find it, start with Arcturus high in the southwest and also locate the end star of the Big Dipper’s handle. Find the place halfway between the two in the sky then look a little below there for the cluster. Binoculars help to find this upside-down “y” pattern of stars.

As dark falls, the two brightest stars that are visible in the evening sky at this time, Arcturus and Vega, are roughly equally high, with Arcturus towards the southwest, Vega toward the east. Arcturus forms the bottom of kite-shaped Bootes the Herdsman, which extends up from Arcturus. Below Arcturus is Spica, the brightest star of the constellation Virgo. Virgo is sprawled across the southern and south-southwestern part of the sky. Following it is the diamond-shaped pattern that is Libra, then the well-defined Scorpius. Brilliant Jupiter is east of the scorpion’s heart, a star named Antares. Following Jupiter and the scorpion is Saturn and the Centaur, commonly known as Sagittarius. Saturn rises late in evening twilight and follows Jupiter as both arc low across the southern sky on these late June nights. Saturn reaches opposition on July 9th when it rises at sunset, passes highest due south at local midnight (standard time), then sets near sunrise.

The traditional summer constellations cover the eastern half of the sky in early evening. Vega is high in the east as the sky gets dark; below and to the left is Deneb, then low in the East is Altair. As each evening passes these three, which form the Summer Triangle, loft higher and higher in the sky. The Moon is a waning crescent in the predawn sky, it is on its way to meet the Sun on July 2 as a total solar eclipse occurs for viewers across the South Pacific and parts of Chile and Argentina. More information about this eclipse can be obtained from the NASA eclipse website.  Other websites, such as www.spaceweather.com and the Exploratorium site will have more information and links to streaming video of the event.

Go to https://www.skyandtelescope.com/observing/sky-at-a-glance/this-weeks-sky-at-a-glance-June-21-29/ where you will find the current “Sky at a Glance” (currently for the week ending June 22). 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 will house our Meade 16-inch advanced telescope and a new 0.6 meter (24-inch) PlaneWave Corrected Dall-Kirkham telescope. 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 could happen as early as Spring 2019. 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.