One last look at the Summer Triangle
As summer turns to autumn, the northern part of the Milky Way is at its zenith in the evening.
Summer's two brightest stars can still be seen after sunset. One is low in the northwest, the other shines a little higher in the west. However, you should check on them before 10 p.m., otherwise the first one will already have disappeared under the horizon. However, if you step outside a little earlier, orange Arcturus (Alpha Bootes), Bear Warden's main star, still twinkles to the northwest.
You will find the second "beacon" a little higher and a little further to the west. It is Vega (Alpha Lyrae) in the lyre. It is as bright as Arcturus but appears blue and white. On our map you will find them halfway between the western horizon and the zenith.
Also high above the horizon are Deneb (Alpha Cygni) and Atair (Alpha Aquilae). They are located east and south of Vega. Together, the three bright stars form one of the most distinctive landmarks of the hot season: the Summer Triangle. It is not an official constellation, but makes orientation in the sky much easier. Deneb stands at the end of the swan. It also forms the tip of the "Northern Cross". This is what is called the brightest area within the constellation, which actually has the shape of a cross. At the other end (or at the head of the swan) stands Albireo (Beta Cygni). If you look at it through a small telescope you can already see its two components, gold and blue. It is one of the most beautiful double stars in the sky.
In a very dark sky you will see a particularly bright area of the Milky Way, the Cygnus star cloud, along the gooseneck. It's one of the most star-rich regions you can explore with binoculars. The swan has other attractions such as the North America Nebula and the Veil or Cirrus Nebula, which you can discover with a telescope, a star map and a little experience. However, for the faint nebulae you definitely need a very dark location.
The third vertex of the Summer Triangle, Atair, marks the eagle's head. It is flanked on either side by fainter stars. Below the eagle lies the shield ("scutum"). Although fairly unremarkable, it contains a very bright area of the Milky Way: the Shield Cloud. Apparently in its center we see the star-rich open cluster M 11, which is much closer to us than the cloud.
Planets in September
Jupiter is the only planet you can easily see with the naked eye in the evening. It shines brightly southwest to west-southwest during and after dusk. The gas planet will pass north of Alpha Librae this month, standing just half a degree alongside it on the 11th and 12th. Mercury and Mars meet on September 15, but both are too close to the Sun to be visible at twilight. Saturn is in the east-southeast at dawn. Also look for Regulus a little to the left below him. Saturn is currently 0.5 magnitude, slightly dimmer than it has been in recent years. Using a telescope, you can easily see the main cause of this: the inclination of its rings has decreased. Venus sinks lower and lower into the dawn. It is low on the eastern horizon.
The Rising Moon will experience an unremarkable partial eclipse on September 7, culminating at around 8:52 p.m. More striking is his encounter with the Pleiades, which he made on December 12. September overcast. A week later, at dawn on September 19, it stands as a crescent between Saturn and Regulus. Two days later, the even narrower crescent appears close to Venus. Back in the evening sky, the waxing crescent Moon is near the horizon below Jupiter on the 25th and below and to the left on September 26.
Unfortunately, the solar eclipse on September 22 cannot be seen from Germany. The umbra moves mainly over the sea, South America and southern Africa. The sun reaches the equinox on September 23 at 6:03 am, heralding the beginning of autumn in the northern hemisphere and spring in the southern hemisphere. © astronomy today
