Today:
Autumn has not discouraged the Summer Triangle, just given us a different view. Seen crossing overhead near midnight in the summer, it now appears overhead in the evening. Look for the faintest of the three stars, Deneb, close to the zenith this evening, while Altair shines in the southwest, and the bluish-white Vega gleams sharply, high in the west.
Thursday:
Directly overhead this evening at 8:10 PM is Deneb, the tail of the Swan, or the top of the Northern Cross. Although Deneb appears as the faintest star of the Summer Triangle, it is by far the most powerful. While Vega shines 40 times brighter than our Sun, and Altair about 10 times brighter, Deneb emits an estimated 200 thousand times more light!
Friday:
Over the next week, a comet rises into the western skies, called Tsuchinshan-ATLAS. As long as it survives it passage around the Sun at the end of September, its climbs higher each evening, very low and in the twilight near due west this evening, its tail almost straight up. Although it gets fainter each night, it appears higher, and later in a darker evening sky.