astronomy club of asheville september 2016 sky events · · 2016-08-01astronomy club of asheville...

Astronomy Club of Asheville

September 2016 Sky Events

The Planets this Month - page 2

Planet Highlights - page 7

Moon Phases - page 10

September 22nd - the Autumnal Equinox - page 11

Find the Zodiacal Light - page 12

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With the exception of the first week of September, when it will be visible very low in the west at dusk, Jupiter will end its long bright stay in our evening sky that began this past spring.

Earth reaches conjunction with Jupiter on September 26th; the two planets are then on opposite sides of the Sun.

Venus, Saturn and Mars are the three bright planets that will dominate our early evening skies all month.

Venus will shine brightly low on the western horizon at dusk.

Mars and Saturn remain in good viewing position in the S-SW skies, but you should observe them early in the night before our planet’s rotation lowers them into the western skies.

Saturn precedes Mars along the ecliptic, as the two planets setin the west-southwest well before midnight for most of this month.


September 2016 Sky Events – the Planets



Conjunction of the Moon with Jupiter and Venus

On the evenings of September 2 & 3, the narrow sliver of the waxing crescent Moon will appear near the bright planets Jupiter and Venus.

A clear unobstructed view low to the W-SW and using binoculars should help you locate the planet Jupiter and the Moon on Sept. 2nd.

Image courtesy of Sky & Telescope



Conjunction of the Moon with Saturn and Mars

On the evenings of September 8 & 9, the first quarter Moon will appear above the bright planets Saturn and Mars.

On these 2 nights, Saturn and Mars are 940 million and 87 million miles, respectively, behind the Moon!

Image courtesy of Sky & Telescope

Mercury reaches inferior conjunction (passing between the Earth and the Sun) on September 12th. It then quickly reaches greatest elongation west (18º) of the Sun on September 28th.

This means the Mercury will be visible in the eastern dawn sky during the last week of September, and this will be its best morning appearance of the calendar year for us northern hemisphere denizens.

Neptune comes into opposition (directly opposite the Earth from the Sun) on Sept. 2nd. This puts the planet at its closest to Earth for the year and also means it will be up in the sky all night. It can be found this month in the constellation Aquarius.

Uranus rises later in the night. It can be found this month in the constellation Pisces.

You will need binoculars or a telescope to locate and observe the small distant planetary disks of Uranus and Neptune.





Mercury and the Moon in the Dawn Skies

In the dawn skies of Sept. 27-29, find the waning crescent Moon in conjunction with the planet Mercury in the east.

Both solar system objects appear in front of the constellation Leo.

Mercury is some 89 million miles behind the Moon on these dates!

Image courtesy of

Sky & Telescope


September 2016 Planet Highlights

Planet Avg. Distance from Earth

Constella-tion(s)

Avg. Diameter in arc seconds

Avg. Mag-nitude

Comments

Page 1 of 3

Mercury 0.83

AUs

Virgo & Leo 8.7 0.3 Reaches greatest

elongation west on

Sept. 28th

Venus 1.4

AUs

Virgo & Libra

11.5 -3.9 Shining brightly

low in the W-

SW at dusk

Mars 0.9

AUs

Scorpius, Ophiuchus & Sagittarius

9.6 -0.1 In the S-SW

skies after

sunset




Constella-tion(s)


Avg. Mag-

nitude

Comments

Page 2 of 3

Jupiter 6.4 AUs Virgo 30.7 -1.7 In conjunction

with the Sun on

Sept. 26th

Saturn 10.1

AUs

Ophiuchus 16.3 0.5 Find Saturn near

Mars in the S-

SW skies at dusk

Uranus 19 AUs Pisces 3.7 5.7 Best viewed

after 10 p.m. this

month




Constella-tion(s)


Avg. Mag-

nitude

Comments

Page 3 of 3

Neptune 29 AUs Aquarius 2.4 7.8 At opposition on

Sept. 2nd


The Moon – September 2016

Unless otherwise indicated, all times are EDT

** The “Harvest Moon” – The Harvest Moon

is the full moon that occurs closest to the September Equinox.

New Moon 1st 5:03 a.m.

First Quarter 9th 7:49 a.m.

Full Moon** 16th 3:05 p.m.

Last Quarter 23rd 5:56 a.m.

New Moon 30th 8:11 p.m.


September 2016 Highlight:The Autumnal Equinox

Autumn begins in the northern hemisphere at 10:21 a.m. EDT on Thursday, September 22nd.

This day marks a point in the Earth’s tilted orbit where all places on the planet experience equal amounts of night – “equi” (equal) “nox” (night) – about 12 hours. And hence equal amounts of daylight as well.

The fall equinox is one of 2 time periods during the year when the Sun actually rises in the east and sets in the west – the other is the spring equinox.

This September Equinox marks the beginning of spring in the southern hemisphere.


September 2016 Highlight

The Zodiacal Light

September begins the season for finding the elusive “zodiacal light” in the early morning sky.

But what is zodiacal light? Zodiacal light is the sunlight reflected from numerous

dust grains located along the plane of the solar system the ecliptic or “zodiac”.

These dust grains are left over from the formation of the solar system (a type of cosmic dust), and their supply is continuously fed by particles from comets and asteroid collisions.

The ecliptic is nearly vertical to the horizon this month providing good viewing opportunities.


September 2016 HighlightThe Zodiacal Light

Zodiacal light is seen as a “cone” of light that is widest at the horizon.

Look for it low in the east (with an unobstructed view) beginning about two hours before sunrise.

The 40-minute prime viewing window closes about 80 minutes before sunrise.

Pick a very dark location far from artificial lights and without moonlight.

The best dates, without moonlight this month, to see the zodiacal light will be from Sept. 1-15 and 27-30.

In this fall season, when the zodiacallight is visible in the eastern morning sky, it is often called the “false dawn”.

Zodiacal Light and the Milky Way


September 2016 HighlightThe Zodiacal Light

astronomy club of asheville september 2016 sky events · · 2016-08-01astronomy club of asheville...

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