What's Up in the Night Sky

October 2013 - Vol. 17, No. 9

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.

Although the Summer Triangle is still visible in the W, the Square of Pegasus is now prominent high in the S. Far below, lonely Fomalhaut [FOE-ma-lot] of Piscis Austrinus still glitters near the S horizon. Between Pegasus and the N pole star, Polaris (Ursa Minor), find the familiar "W" shaped asterism of Cassiopeia. If you are fortunate to be viewing from a dark site, you will also see the constellations, Perseus and Auriga, with its bright star, Capella, embedded in a starry band stretching across the night sky from E to W. You are looking at the Milky Way, one of the spiral arms of our galaxy. In the E the constellations, Gemini, with its bright twin stars, Castor and Pollux, and Orion, with its distinctive hour glass asterism, rise above the E horizon. Now the Big Dipper (Ursa Major) dips low in the N.

MERCURY favors the southern hemisphere during the month of September, returning from superior conjunction to the sunset sky.. VENUS visible in the evening sky, magnitude -4.0+, also favors the southern observers. JUPITER, rises after midnight, in the constellation of Gemini. MARS is visible in the morning sky this month, moves into Leo this month, near M44 in Cancer early in the month. SATURN is still visible, setting in the evening twilight. Uranus is nearing opposition on October 3, can be located in Pisces..

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. Unfortunately some of these events may occur during daylight hours in your area.

DATE	EVENT
01	Mars 7 deg N. of the Moon. The crescent Moon rises below Jupiter in the morning sky. Mars will be close by as it moves into Leo this month, the two planets and the crescent should be a lovely trio near Castor and Pollux, the twins of Gemini.
03	Uranus at Opposition. Check the sky for the Zodical Light in the early mornings for the next two weeks. The Zodiacal Light or "false dawn" is visible in the E about 2 hours before sunrise. This pyramidal glow is caused by meteoroids, dust particles spawned by passing comets, etc., that have settled into the ecliptic plane (path followed by the Sun, Moon and planets), reflecting the Sun’s light before it rises.
06	Mercury 3 deg S of the Moon.
07	Saturn 1.9 deg N of the Moon.
08	Venus 5 deg S. of Moon. This will be a good week to watch the SW sky show Draconid meteor shower, unpredictable rate per hour. The radiant of this shower is from the constellation Draco, or Dragon. The shower occurs when the Earth travels through dust left in the path of the periodic comet Giacobini-Zinner.
09	Mecury at Greatest Elongation E. Mercury 5 deg S. of Saturn.
10	Moon at perigee.
14	Mars 1 deg N of Regulus.
16	Venus 1.6 deg N of Antares. This will be a good naked eye observation after sunset. Make sure you have a good horizon to the SW. Venus and Antares will continue to put on a good show.
18	Penumbral eclipse of the Moon, best visible from Europe, Africa, parts of S. America and the easternmost N. America. Best seen within half an hour of the greatest eclipse, at 23:50 UT. Although the Moon will be over the horizon for most major population centers, this type of eclipse is hard to observe
20	Venus 4 deg N. of Saturn.
21	Orionid meteor shower, with predicted rate of 20-25 per hour. This shower is caused by debris left by the famous periodic comet, Halley.
26	Jupiter 5 deg N. of Moon, and the Moon at apogee. This will be a good time to watch Jupiter interacting with the bright stars of Gemini.
30	Mars 6 deg N of Moon.

Lunar Almanac for October 2013

Phases of the Moon	Phase and Date(s)	Best viewed before local midnight
	New 05	Deep Space Objects
	1st. Qtr 12	Planets & Moon
	Full 19	Moon
	Last Qtr 26	Deep Space & Planets

Cygnus and Aquila

Although summer in the northern hemisphere is waning, the Milky Way galaxy stretches from Sagittarius through Cygnus and beyond. The Cygnus arm of the Milky Way and it's Great Rift provides a startling contrast of bright and dark nebulosity, stars so numerous that they provide milky pathways through the sky. The Swan will be with us through the fall, until the constellation stands as a giant cross in the west on Christmas Day. The birds of summer are northernly creature. In addition the eagle is still flying, through he sets earlier than his more northerly companion. The constellation of Aquila was associated with one of the greatest of all predatorial birds, the Eagle. Some modern observers see an airplane rather than a bird. The location constellation on the celestial equater takes it high across the sky from East to West for observers at northern latitudes..

This sharp-sighted sky bird is dominated by the first magnitude star, Altair. This star is one of the closest bright stars in the sky, a mere 16 light years from our sun. This star is 1.5 times larger than our sun and rotates in a short 6 hours, causing the star itself to be flattened into an elliptical shape. It may be twice as large at the equator as it is a the poles. Altair is flanked by two stars, Alshain (beta) at mag 3.7 and Tarazed (gamma) at magnitude 2.7, making it easy to identify from even a suburban site.

Aquila is located in the summer Milky Way, near the dark rift that is called the Great Rift. Many of the stars in Aquila have long been shining in the galaxy and the constellation is the home of many planetary nebulae. The best of these are NGC 6751 and NGC 6781, they will be challenging but may be worth the reward. Panning through the constellation with binoculars will reveal the dark nebulae that abound in this constellation. For telescopes, the best of these is just west of Gamma Aquilae is B143, with two dark prongs that may been seen in an 8-inch telescope or greater. Nebulae like these are only detectable by the star studded fields they occupy.

Aquila the flying eagle

On June 8, 1918, the Lick Observatory astronomer, E.E. Barnard and the young amateur, Leslie Peltier who was a well-known comet hunter and variable star observer both spotted a nova in Aquila that peaked out at an estimated magnitude of -1.4, V603 Aquilae. An even brighter nova was reported in the constellation in the year 389 that was said to outshine the planet Venus. The constellation harbors many planetary nebula due to the age of the stars located there. The galactic star cluster NGC 6709 at mag 8 contains about 40 stars. Aquila is not close to the center of the galaxy, however, that we can not see other galaxies that are located in the constellation. Notably, the galaxy NGC 6814, at mag 12.2 might be found in a larger amateur instrument.

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