The June night sky

By CLIVE JACKSON features@algarveresident.com

Clive Jackson is the Director of the Astronomical Observatory of Tavira (Sitio do Malhão, Tavira) and the Camera Obscura (next to the Castle in Tavira), specialising in education and public outreach.

This month we have the longest days and the shortest nights of the year in the Northern Hemisphere.

This year the summer Solstice falls on the 21st at 6.45am local time and on that day the sun rises and sets at its most northerly point on the horizon. Although this day is commonly known as midsummer’s day, it is officially the start of summer and lasts until the autumn Equinox in September.

Just after dark in June, over on the western horizon, we have the last chance to see the ringed planet Saturn. This planet is in the constellation of Leo and, by the end of June, Saturn sets before midnight.

Rising in the east at around 3am we have the brilliant planet Venus. This planet is in the constellation of Aries and is the brightest object in the nighttime sky apart from the Moon.

On June 6, Venus is at its greatest distance from the Sun and through a small telescope would appear as an exactly half illuminated disk.

Just before midnight the planet Jupiter can be seen rising over on the southeast horizon. This planet is in the constellation of Capricorn and will be at its biggest and brightest in the month of August.

Low on the southern horizon, during the hours of darkness in June, we can see a red giant star called Antares. This star is in the constellation of Scorpius and is one of the largest stars in the sky with a volume of around one million times that of our sun. But through a telescope it will still only be seen as a sparkling point of light as it is hundreds of light years distant.

Red Giant stars are at the end of their lives and can explode as a supernova when they finally run out of nuclear fuel. We have not witnessed a supernova explosion in our galaxy for around 500 years and Antares is a prime candidate for one, and if it went supernova it would shine as bright as the full Moon in our sky for many weeks and be visible in daylight. This could happen anytime in the next million years, so you will have to be patient!

The full Moon is on June 7 and will be one of the lowest full Moons of the year. The reason is that in the summer the Sun is high in the sky and the full Moon has to be low as it is 180 degrees opposite to the Sun.

The Moon is Full on June 7 and Last Quarter on June 15 and New on June 22, and First Quarter on June 29.

Clive Jackson can be contacted by phone on (00351) 281 321 754, by fax on (00351) 281 324 688, or by email to features@algarveresident.com. To visit his website, click on the link to the right of this page.