SkyEye

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

January 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	Tue
2	Wed	Earth at perihelion
3	Thu	The waning gibbous Moon does not favour the Quadrantids (theoretical peak activity: 13:30 UT).
4	Fri
5	Sat	The Last Quarter Moon occults the first magnitude star Spica. This event is visible from western Australia from about 18:00 UT.
6	Sun
7	Mon
8	Tue
9	Wed
10	Thu	Moon at perigee
11	Fri	New Moon
12	Sat
13	Sun
14	Mon
15	Tue
16	Wed
17	Thu
18	Fri	Mercury at superior conjunction
18	Fri	First Quarter Moon
19	Sat
20	Sun
21	Mon
22	Tue	As seen from the central portions of South America, the Moon occults Jupiter from about 3:30 UT.
22	Tue	Moon at apogee
23	Wed
24	Thu
25	Fri
26	Sat
27	Sun	Full Moon
28	Mon
29	Tue
30	Wed	Saturn at west quadrature
31	Thu

Coming up next month...

Next month distant Neptune reaches solar conjunction.

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: Sagittarius » Capricornus
The Earth makes its annual closest approach to the Sun on 2 January. The date of perihelion can range from New Year's Day to 5 January.
Mercury: Sagittarius » Capricornus
Found in the east just before sunrise, this elusive planet is sinking back towards the horizon on its way to superior conjunction on 18 January. It reappears in the evening sky at the end of the month.
Venus: Sagittarius
The morning star appears low in the southeastern dawn sky. It is best viewed from the southern hemisphere.
Mars: Capricornus » Aquarius
The red planet sets soon after the Sun, making it difficult to see in the evening twilight.
Jupiter: Taurus
At opposition last month, the largest planet in the solar system is visible well into the early morning hours. It flirts with the Pleiades at the end of the month.
Saturn: Libra
The ringed planet rises just after midnight. At west quadrature on 30 January, this is an excellent time to enjoy the enhanced 3-D effects of the elongated shadows cast by the rings on the planet and vice versa.
Uranus: Pisces
This ice giant was at east quadrature near the end of last month and sets by late evening.
Neptune: Aquarius
A small telescope is necessary to view the most distant planet in the solar system. However, with solar conjunction approaching next month, it may be too close to the Sun to easily observe.

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 the spectacular planetary nebula NGC 2818 which lies in the southern constellation of Pyxis. A planetary nebula is a glowing shell of gas surrounding a dying star. When a star begins to run out of fuel and expands into a red giant, the outer layers of the star are expelled into space, enriching the surrounding area with the heavy elements manufactured by the parent star. The remaining hot stellar core ionises the ejecta, causing it to glow for a few tens of thousands of years. Eventually the star fades away and nebula is no longer visible. Our own Sun will meet such a fate but not for another 5 billion years or so. This image was taken by the Hubble Space Telescope in November 2008 and is courtesy NASA, ESA, and the Hubble Heritage Team (STScI/AURA). The red colour represents nitrogen, green represents hydrogen and blue represents oxygen.