SkyEye

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

June 2011

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	Wed	New Moon
1	Wed	Partial solar eclipse: visible from North Korea, Japan, northeastern China, northeastern Russia, northern Alaska, northern Canada, Greenland and Iceland.
2	Thu
3	Fri
4	Sat
5	Sun
6	Mon
7	Tue
8	Wed
9	Thu	First Quarter Moon
10	Fri
11	Sat
12	Sun	Moon at perigee
12	Sun	Mercury at superior conjunction
13	Mon
14	Tue
15	Wed	Total lunar eclipse: visible everywhere except for most of the Americas.
15	Wed	Full Moon
16	Thu
17	Fri
18	Sat
19	Sun
20	Mon
21	Tue	Solstice
22	Wed
23	Thu	Last Quarter Moon
24	Fri	Moon at apogee
25	Sat
26	Sun	Uranus at west quadrature
27	Mon
28	Tue	Pluto at opposition
29	Wed
30	Thu

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: Taurus » Gemini
A solstice occurs on Earth on 21 June. The word solstice means "sun stands still" so that on this day, the solar declination reaches an extreme. In this case, the Sun appears directly over the Tropic of Cancer in the northern hemisphere. From now until the solstice in December, days will be getting shorter in the northern hemisphere and longer in the southern hemisphere. Earlier in the month, the Sun participates in two eclipses, a partial solar eclipse on 1 June and a total lunar eclipse two weeks later.
Mercury: Taurus » Gemini
The closest planet to the Sun undergoes superior conjuntion on 12 June so it is visible low in the east before sunrise only for the first few days of the month. By the end of the month it reappears in the west after sunset, close to the horizon but rapidly climbing when seen from the southern hemisphere.
Venus: Aries » Taurus
The "morning star" is slowly descending towards the eastern horizon but is still easy to spot from southern latitudes.
Mars: Aries » Taurus
The red planet is still in the vicinity of Venus following last month's close encounter in the dawn sky.
Jupiter: Pisces » Aries
A morning sky object, Jupiter is slowly climbing away from the Sun.
Saturn: Virgo
Saturn is well-placed for viewing, high above the horizon as the Sun sets and staying aloft until well after midnight. Look for it near the third-magnitude double star gamma Virginis (or Porrima) early in the month.
Uranus: Pisces
Rising just after midnight, this gas giant reaches west quadrature on 26 June.
Neptune: Aquarius
A small telescope is necessary to view the most distant planet in the solar system. At west quadrature last month, look for Neptune rising in the east shortly before midnight.
Pluto: Sagittarius
Now classified as a "dwarf planet", tiny Pluto reaches opposition on 28 June and is up all night. At its brightest it's only fourteenth magnitude so a moderate-sized telescope (about 30 centimetres or 12 inches) and an excellent finder chart is necessary to locate this distant object.

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 beautiful planetary nebula NGC 2818. 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. 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.