SkyEye

Welcome to SkyEye, your guide to this month's celestial events.

September 2013

The Calendar

All times and dates are given in Universal Time (UT).
Nightly darkness estimates are calculated for 45° N and 30° S.
Like total solar eclipses, lunar occultation events can be seen only from limited regions on Earth (and sometimes not at all if the occultation takes place during daylight hours). However, the Moon will appear close in the sky to its 'target' for some hours either side of the actual occultation, regardless of where you are.

Date		Event
1	Sun	The Aurigids (formerly known as the Alpha Aurigids) will have nearly ideal skies when they peak at around 02:00 UT.
2	Mon
3	Tue
4	Wed
5	Thu	New Moon
6	Fri
7	Sat
8	Sun	The Moon occults first-magnitude star Spica: visible from the Middle East and Russia from about 13:00 UT. Then, a little later in the day, the Moon occults Venus: partly visible from the southern part of South America from 21:50 UT.
9	Mon
10	Tue
11	Wed
12	Thu	First Quarter Moon
13	Fri
14	Sat
15	Sun	Moon at perigee
16	Mon
17	Tue
18	Wed
19	Thu	The Full Moon nearest to the September equinox is traditionally known as the 'Harvest Moon' in the Northern Hemisphere.
20	Fri
21	Sat
22	Sun	Equinox on Earth
23	Mon
24	Tue
25	Wed
26	Thu
27	Fri	The Last Quarter Moon reaches apogee on the same day.
28	Sat
29	Sun
30	Mon

Coming up next month...

Giant Jupiter is at west quadrature, possibly the most interesting time to point a telescope at it, and northern hemisphere observers can look for the Draconids flashing across the sky.

The Solar System

The word planet is derived from the Greek word for 'wanderer'. Unlike the background stars, planets seem to move around the sky, keeping mostly to a narrow track called the ecliptic, the path of the Sun across the stars. Dwarf planets and small solar-system bodies including comets, are not so constrained, often moving far above or below the ecliptic.

Sun: Leo » Virgo
The solar north pole is most inclined toward the Earth early this month. An equinox occurs on Earth on 22 September. The word equinox means 'equal night' so that on this day, the (centre of the) Sun spends an equal amount of time above and below the horizon everywhere on the planet.
Mercury: Leo » Virgo
For southern hemisphere observers, Mercury appears in the west at sunset and rapidly climbs higher every night for the best evening apparition of the year. For those in northern latitudes, however, this elusive planet remains mired in the twilight close to the western horizon.
Venus: Virgo » Libra
The evening star continues to climb high in the west after sunset for southern hemisphere viewers but remains stubbornly low for those looking for it from the northern hemisphere. From 22:00 UT onwards, the southern parts of South America will see Venus emerge from an occultation by the Moon on 8 September.
Mars: Cancer » Leo
Mars continues to pull away from the Sun, making it increasingly easier to find in the early morning hours.
Jupiter: Gemini
Now rising around midnight (and quite a bit earlier in the northern hemisphere than in the southern), Jupiter continues to brighten as it heads towards its next opposition in January 2014.
Saturn: Virgo » Libra
The ringed planet is becoming increasingly difficult to spot in the early evening for northern hemisphere observers but is still easy to find from southern latitudes as it descends into the evening twilight.
Uranus: Pisces
Uranus rises in mid-evening and is getting ever brighter as it approaches opposition early next month.
Neptune: Aquarius
A small telescope is necessary to view the most distant planet in the solar system. Opposition was last month so it is aloft most of the night, setting only just before dawn.

The Celestial Sphere

Constellations are patterns of stars in the sky. The International Astronomical Union (IAU) recognises 88 different constellations. The brightest stars as seen from the Earth are easy to spot but do you know their proper names? With a set of binoculars you can look for fainter objects such as nebulae and galaxies or some of the closest stars to the Sun.

Descriptions of the sky for observers in both the northern and southern hemispheres are available for the following times this month. Subtract one hour from your local time if summer (daylight savings) time is in effect.

Local Time	Northern Hemisphere	Southern Hemisphere
1730 hours (1830 hours summer time)	45° N	30° S
1930 hours (2030 hours summer time)	45° N	30° S
2130 hours (2230 hours summer time)	45° N	30° S
2330 hours (0030 hours summer time)	45° N	30° S
0130 hours (0230 hours summer time)	45° N	30° S
0330 hours (0430 hours summer time)	45° N	30° S
0530 hours (0630 hours summer time)	45° N	30° S

For More Information...

Consult our online glossary for non-technical explanations of many of the astronomical terms used in these pages.
Blue moons, eclipses, the dates of Easter and much more can be found at the Interactive Astronomy Pages.
For more information about the objects and events described in SkyEye, visit these astronomy-related sites.

Credits

Much of this information can be found in this month's issue of your favourite amateur astronomy magazine available in your local bookshop. Another excellent source is the current edition of the Astronomical Calendar by Guy Ottewell and published by the Universal Workshop.

The SkyEye banner features a Hubble Space Telescope image of the open star cluster NGC 265. But this object is not a member of our galaxy, rather it's part of the Small Magellanic Cloud! It is about 65 light years across and located 200,000 light years away in the constellation of Tucana. This 26-minute exposure from November 2004 is courtesy of ESA and NASA.