47 TUCANAE

NGC 104

Tucana, the Toucan Bird.  In the skies the Toucan is one of three exotic bids which are grouped around the South Pole. 

Smaller than Omega Centauri but still one of the largest globular clusters of the sky.

Located at an estimated distance of 15,000 light years from us, and visible from the southern hemisphere in the constellation of Tucana.

ALPHA CENTAURI

Alpha Centauri is famous in the Southern Hemisphere as the outermost “pointer” to the Southern Cross.

It is a system of three stars, one of which is the fourth brightest star in the night sky.

It is the closest star system to our Solar System – 41.5 trillion km

The three star system is 4.36 light years away, meaning light requires 4.36 years to travel from the stars to Earth, and so we see them as they existed 4.36 years ago.

ANTARES

Antares is a star in the Milky Way galaxy and the sixteenth brightest star in the night-time sky.  It guides us to one of the great constellations of the sky, Scorpio, the celestial scorpion, one of the few constellations that actually looks like what it represents.

It is a  super giant gleaming red at the scorpions heart, has a colour similar to Mars.

Diameter 700 times that of the sun, and 600light years from our Solar System.

SIRIUS

Sirius is the brightest star in the night sky, due to its closeness to the Sun, and called the “dog star”.

 It is a hot white star that will shine brightly for a long time to come.

Known also as a binary system, with a tiny white dwarf star.

Sirius is about two and a half times the size of the Sun, but nearly 26 times brighter.  At 8.7 light years away, its one of the closest stars to us as well.

JUPITER

Jupiter is the fifth planet from the Sun and the largest planet in the Solar System, and the brightest after Venus.

Named after the Roman King of the Gods.

Its mass is 318 times larger than Earth.

Distance from Earth 588 million km.

Gravity is 2.4 times stronger than Earth. Object that weighs 100 pounds on Earth would weigh  240 pounds on Jupiter

Jupiter takes about 12 earth years to do a complete loop around the Sun.

It spins on its axis faster than any other planet and its day is slightly less than 10 hours long.

Galileo in 1610 discovered Jupiter’s four large moons-

Io, Europa, Ganymede and Callisto. 

Jupiter has 16 satellites that measure 10 kilometers in diameter. It also has many small satellites – total altogether of 63.

Jupiter is 90% hydrogen and 10% helium with traces of methane, water, ammonia.  It is a giant gas ball with a solid core.

Temperature at the top of clouds is -230degrees F (-145c)

Near planets centre 43,000 degrees F (24,000c) - hotter than the surface of the sun.

The planet radiates about twice as much heat into space as it receives from sunlight.

Jupiter has a set of rings, but hard to see compared to Saturn, only 30km thick.

Spacecraft Galileo orbited Jupiter for eight years, and its atmospheric probe goes down only 150km below the cloud tops.

Jupiter and the other gas planets have high velocity winds which are confined in wide bands of latitude. The winds blow in opposite directions in adjacent bands. Chemical and temperature differences between these bands are responsible for the coloured bands that dominate the planets appearance.  Light coloured bands are called zones, dark ones belts. The Galileo probe indicate that the winds are faster than expected – more than 400mph and extend down thousands of kilometres into the interior.  Winds are driven by internal heat.

The Great Red Spot looks practically the same as it was 340 years ago.  It stands 8km above the surrounding atmosphere, roughly the height of Mt. Everest.  A high pressure area.

Size of Spot - 40,000km dia.

SATURN

Saturn is the sixth planet from the Sun and the second largest.

Roman mythology, Saturn is the god of Agriculture.

Nasa visits Pioneer 11 in 1979, Voyager 1 & 2, and Cassini orbiting for four years since 2004

Saturn is 75% hydrogen 25% helium with traces of water, methane,ammonia and rock. Similar to Jupiter.

It takes 29.46 years to go around the Sun.  It spins very fast and a day lasts for 10 hours 39 min.

Winds at the equator travel at 1,700km/hour.

The rings of Saturn are very thin, less than 1,000metrre thick.  Composed primarily of water ice, but may also include rocky particles with icy coatings.

Saturn looks like a bright golden star. It spends the year in Leo, the Lion, and for much of the year is close to Leos “heart” the bright star Regulus.  Saturn is at its best in late February, when its closest to Earth.  It disappears behind the Sun in July and August, then returns to view in the morning sky.