August, for me, is the start of a new observing season. Astronomically dark skies return to Northumberland, the Milky Way is at its best and we have one the most reliable meteor showers of the year. And all under reasonably warm summer skies!
Brilliant Venus, which has been a fixture in the evening sky for several months, will become increasingly difficult to see this month. The planet is its approaching maximum angular distance from the Sun but is positioned almost on the horizon just after sunset. Observers in more southerly latitudes are continuing to have a superb view of the planet. In Northumberland, unless you can find it with a telescope during daylight hours, Venus will not be visible after sunset from the second week of August.
Jupiter is over the southwest horizon after sunset, shining at magnitude -2.0. Jupiter is among the stars of Libra and the first quarter moon is nearby on August 17th.
Saturn, in Sagittarius, is above the southern horizon as twilight fades from the sky. It’s shining at magnitude +0.3 and the rings are displayed at nearly their widest possible angle. Small telescopes should easily show Titan and Rhea, the two largest moons.
Mars can be found in the southeast shortly after sunset. The planet reached opposition at the end of July and is brilliant at magnitude -2.5. The colour is an unmistakable rusty orange. Mars is in the southern constellation of Capricornus and is never more than 10 degrees above the horizon in Northumberland. Observing Mars so low in the sky is a frustrating experience; the Martian disk is refracted into red and blue components and atmospheric seeing needs to be near perfect to see any surface details.
The Milky Way has been masked by all night twilight from late May until late July returns to the astronomically dark skies of August. The central regions of the Milky Way which lie in the general direction of Sagittarius are difficult to see from Northumberland and barely skirt above the horizon for more than a few hours at a time. There is a window of opportunity during August to observe some of the deepsky objects in this part of the sky.
One of my favourites is the Lagoon Nebula and Triffid Nebula.
These are very challenging objects to see from Northumberland; the low altitude dims them significantly! The planet Saturn serves as a guide in 2018; the nebulae are just a couple of degrees to the west in the sky. Binoculars will show them.
More stars and constellations of the August night sky – and the Perseid meteors – coming soon!