July 20 th to August 16 th General Information July/August: Spanning the constellations from Perseus to Norma, the summer Milky Way rises higher and higher.

What’s UpHighlighting the Near

and Deep Sky July 20, 2015 toAugust 16, 2015

July 20th to August 16th

General Information

• July/August: • Spanning the constellations from Perseus to Norma, the

summer Milky Way rises higher and higher toward zenith as the hours and days pass during this period.

• With Venus and Jupiter having nearly set as darkness gathers, Saturn and its remarkable rings take center stage.

• Though there are some grand galaxies to be seen, this period is prime time for viewing star clusters and nebulae.

• Sunset Range: 8:37 p.m. (July 20th) to 8:09 p.m. (August 17th)

• End of Astronomical Twilight (Full Darkness* – Sun 18° below horizon): 10:24 p.m. (July 20th) to 9:45 p.m. (August 17th)

* Usually dark enough for observing about a half hour before this.

Moon Phases – July/August

• July 24th – First Quarter Moon

• July 31st – Full Moon

• August 6th – Last Quarter Moon (Observing at Cahas on 7th and 8th)

• August 14th – New Moon (Observing at Cahas on 14th and 15th)

Roughly speaking:

• First Quarter Moon is highest at sunset and sets at midnight• Full Moon rises at sunset and is in the sky all night• Last Quarter Moon rises at midnight and is highest at dawn• New Moon sets with the sun and is absent from the sky all night

Celestial EventsJuly 20th to August 16th

• July 21st: Moon at apogee; distance 63.47 Earth radii.

• July 23rd: Venus stationary in right ascension and begins retrograde (westward) motion.

• June 26th: The Equation of Time reaches a “shallow minimum” of –6.54 minutes (clocks complete 24 hours this much faster than the Sun completes a Meridian to Meridian cycle).

• August 2nd: Moon at perigee; distance 56.78 Earth radii (10.5% closer than July 21st apogee).

• August 12th: Escorted by the Rosetta craft and carrying the Philae lander, Comet 67P Churyumov-Gerasimenko reaches perihelion, 1.243 AU from the Sun and 1.77 AU from Earth. It’ll be in Gemini, 22° high in the SE an hour before sunrise, at 11th to 14th magnitude. (Good luck!)

• August 12th-13th: Perseid Meteor Shower. It’s nearly New Moon, making this a favorable year as far as dark sky conditions.

Orbits and planet sizes not to scale

Mean Distance from Sun (AUs)

Mercury: 0.39 Jupiter: 5.20 Venus: 0.72 Saturn: 9.52 Earth: 1.00 Uranus: 19.20 Mars: 1.52 Neptune: 30.74 Pluto: 39.73

Planets’ Positions

June 15th (last meeting date)

July 20th

June 15th, 9:45 PMLast month’s meeting date.

Meridian

July 20th, 9:45 PM

MeridianMeridian

July 20th, 9:45 p.m.

Pluto

The Blinking Planetary

NGC 6826 / C15

M22 M13

Alcor

Mizar

“La Superba”(Y CVn)

Pluto

The “Teaspoon”

The “Teapot”

Finding Pluto Takes Some Doing!

Chart: Sky & Telescope

At 14th magnitude, Pluto will test the light gathering limits of an 8” reflector, a 5” refractor or a 6” SCT.

Being sure you’ve seen Pluto requires observing what moved for at least 2 nights.

Pluto is spending all of 2015 in the “Teaspoon” of Sagittarius.Sagittarius

Questions???