What's Up in the Night Sky

June 2016 - Vol. 20, No. 6

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.

Spica (Virgo) glows in the SW while Regulus (Leo) vanishes over the W horizon before midnight. The "big dipper" (Ursa Major's asterism) now stands on its "handle" in the N. Antares (Scorpius) is low on the S horizon. The Eastern sky is dominated by the "summer triangle" asterism: Deneb (Cygnus), Vega (Lyra) and Altair (Aquila). An interesting star tour begins at the last star of the big dipper's handle, Alkaid. Following the curve of the handle, "arc to Arcturus". Now, following the same curve, "spike to Spica" and "continue to Corvus", its distinctive four star, kite-shaped, asterism.

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.
05	Mercury at greatest elongation W.
06	Venus at superior conjunction.
10	Regulus 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 05	Deep Space Objects
	1st. Qtr 12	Planets & Moon
	Full 20	Moon
	Last Qtr 27	Deep Space & Planets

Topic of the month: Hercules

Finder chart for Hercules The 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.