What's Up in the Night Sky?

June 2016 - Vol. 20, No. 6

Astra's Star Gate

This Month's Night Sky - NOTE: The next paragraph describes the sky as it appears at 10 pm EST (11 pm EDT) near mid- month. The sky also looks this way at 11 pm EST (midnight EDT) during the beginning of the month and at 9 pm EST (10 pm EDT) by month's end.

As May brings the lengthening days, the hours of nightly observation decrease as well, it is always with a bit of sadness that we say good-bye to the Winter and Spring constellations, Gemini, Leo, and Virgo. The early evening presence of Arcturus, the second brightest star in the northern sky, reminds us that the bright star clouds of the Milky Way will soon be brightening up those dark evenings when the Moon is small enough to allow us to truly enjoy those galactic treasures. As the evening turns to morning, the bright stars of the summer triangle follow until just before sunrise, the Milky Way is at the zenith, high overhead. Long twilight hours come to the northern hemisphere.

MERCURY is well placed in the evening sky this month with a close conjunction with the moon on the 3rd. Look for the new moon in the arms of the old! VENUS is too close to the Sun to be observed this month, reachers superior conjunction early in the month.. MARS just past opposition on May 22, will be visible all night in competition for the "reddest star" with Alpha Scorpii, Antares. JUPITER still in Leo, will be in conjunction with the moon on June 11. SATURN, located in Ophiuchus, will reach opposition on June 3. URANUS is in Pisces, favors observers in the southern hemisphere. The outer planet NEPTUNE still in the constellation of Aquarius rises after midnight.

Review how to determine Angular Measurement.

Calendar of Events

NOTE: For those observers not in the ET zone, convert the calendar times to your zone's time by subtracting one hour for CT, two for MT and three for PT. Don't forget to adjust for Daylight Savings Time when necessary by subtracting one hour from your planisphere's time. Dawn and dusk times must also be corrected. See your local newspaper, TV news, or cable TV's Weather Channel for sunrise and sunset times or check with the U.S. Naval observatory. Unfortunately some of these events may occur during daylight hours in your area.

DATE EVENT
03

Saturn at opposition, 7 hours UT

Moon at perigee.

Mercury .7 deg N. of Moon, occultation from Antarctica, southern Africa and Madagascar
05 Mercury at greatest elongation W.
06 Venus at superior conjunction.
10

Regulas 2 deg N. of the Moon.

11 Jupiter 2 deg N. of Moon, a nice conjunction in the evening sky.
15 Moon at apogee.
20 Solstice, summer begins in North America.
26 Neptune 1.2 deg S. of the Moon.
22 Mars stationary.
23 Vesta in conjunction with Sun.
30 Mars closest approach to Earth, for this opposition, the planet will be a mere 46.8 million miles at 22h UT.

Lunar Almanac for June 2016

Phases of the Moon Phase and Date(s) Best viewed before local midnight
new moon New
05
Deep Space Objects
first quarter moon 1st. Qtr
12
Planets & Moon
full moon Full
20
Moon
last quarter moon Last Qtr
27
Deep Space & Planets

Topic of the month: Hercules

Finder chart for HerculesThe constellation of Hercules commemorates the beloved hero of the myths. Hercules was a mortal who performed 12 labors, reminding Astra that there are 12 constellations on the ecliptic that are recognized as belonging to the Zodiac, or celestial zoo. On the Hercules finder chart, we can see that this celestial hunter is located between Lyra and Corona Borealis, two favorite summer constellations. The constellation is recognized by four stars that form the "Keystone", a trapezoid of stars that form the body of the figure. These stars ride high overhead in the Summer sky. This figure is thought to be kneeling. In myth, Hercules was the daughter of Zeus and a mortal woman, making him an enemy of the goddess Hera, who hated him.

The brightest star of Hercules is Ras Algethi, a red giant star that fluctuates in brightness from 3.1 mag to 3.9 or between 3rd and 4th magnitude. It is one of the largest red giant stars known, a full 600x larger than our own sun. This star is also a double star, its companion is a blue-green star that shines at 5.4 mag.

The Hercules and the 12 labors were commemorated on coins from many cultures as far back as 450 BC. Alexander the Great minted coins of Hercules, from whom he claimed he descended. Ancient Greek and Roman coins also depicted our kneeling hero and his labors. The coins with that were cited in the Bible as the thirty pieces of silver bestowed upon Judas Iscariot for the betrayal of Christ presumably were minted with images of our hero. Even the Spanish cast Hercules on their Pieces of Eight. In modern times, the 12 labors and Hercules have been minted on 2-pound coins.

Deep sky observers enjoy views of the Great Globular Star Cluster M-13, the finest such cluster in the northern hemisphere. It's magnitude is recorded as 5.7 and it has been observed on moonless nights by keen sighted observer. The Great Cluster has been measured at 23'. Another fine globular M-92 is also present in the constellation, but is overshadowed by its larger, brighter cousin. M-92 is 6.5 mag and 8' in diameter.

--See You Under the Stars!
Astra for Astra's Almanac

The star chart above was generated by Stellarium, a free open source planetarium program. The above image was created by Dawn Jenkins, using Stellarium and a graphic editing program to format the image for this web page. Editing was done for educational purposes only. Stellarium offers much more to amateur astronomers and is being used in planetariums and to guide telescopes in the field. Simple charts like the one above can be used on the internet for non-profit, illustration purposes. Proper credit is due of course! Thank you to the makers of this fine program from Astra's Star Gate.

This installment of "What's Up?" is ©2016 by Dawn Jenkins for Astra's Stargate. View Ron Leeseburg's Farewell Issue for information on where to find information such as is presented in this almanac.