Star gazing with Astronomical Society president Toby Tobias

During the month of June, the planet Saturn and star Spica appear midway down the north sky.

They are similar in brightness and colour. Saturn is the lower of the two and a nice sight in a small telescope. To their left is the planet Mars; it has an orange hue. Sirius is the brightest star at dusk, and appears in the west. Crux, the Southern Cross is south of the zenith. Beside it are 'The Pointers' Beta and Alpha Centauri. Alpha Centauri is the closest naked-eye star, 4.3 light years away. Scorpius, upside down, is midway up the eastern sky. Below it is Sagittarius; its brighter stars making 'the teapot'.

On Wednesday June 6 New Zealanders will be able to observe the planet Venus in transit across the face of the Sun. This transit of Venus will be visible from all of New Zealand, and will not occur again for 105 years. The planet will begin to make a tiny dent in the bottom edge of the sun just after 10.15am NZST. It is fully onto the sun's edge by 10.34am. Venus's disk will be 1/30th of the sun's diameter. It is midway toward the centre of sun's disk at 1.30pm After that it moves toward the edge. It begins to leave the sun's disk at 4.25pm and is fully off the sun by 4.44pm.

A word of caution; safe methods must be used to view the sun. Viewing the sun directly can result in instant blindness. The safest way is to project the image of the sun onto a suitable screen. Alternatively a specially designed solar filter may be placed in front of the telescope. It is not safe to use a filter at the eyepiece as the focussed heat from the sun could shatter it. If unsure of safe methods, consult your local astronomical society about suitable ways of observing the sun.

Tauranga Astronomical Society will open the observatory at Fergusson Park to the public on June 6 from 10am to 4pm, for the duration of the transit event. Adults will be charged $2 at the door, kids' admittance is free.

The TAS Observatory is located at the clubrooms in Fergusson Park, Matua. Public meetings are every second and fourth Tuesday of the month at 7.30pm.

For more information, phone 07 543 5358.

Data courtesy of Stardome, Auckland and the Royal Astronomical Society of New Zealand.