Chapel Hill Astronomical and Observational Society

Facing South and looking almost straight overhead, you’ll see two bright stars. The one to the right is Arcturus, and the one to the left is Vega. To the left of Vega, you’ll see another bright star, not quite as bright as Vega-that’s Deneb. And below Arcturus, another star similar in brightness to Deneb, is Altair. Using the map below, see if you can make a triangle out of Vega, Deneb, and Altair. That configuration is called the Summer Triangle.

A lot lower in the southern sky, see if you can make out Sagittarius-it looks like a teapot, but the stars here are nowhere near as bright as the three that make up the Summer Triangle.

Here is a list of things you should be able to see in Summer with just ordinary binoculars (7 x 35).

  • Corona Borealis – Between Arcturus and Vega
  •  M3 – Star cluster, near Arcturus
  •  M4 – Star cluster, near Antares
  •  M22 – Star cluster, just left of Sagittarius’ top
  •  M17 – Swan Nebula, in Sagittarius
  •  M8 – Lagoon Nebula, in Sagittarius
  •  M24 – Star cluster, in Sagittarius
  •  Summer Triangle – Vega, Altair, Deneb

You can use this diagram as a guide. It can be downloaded at The orientation for the map is set for South, with the middle of the circle representing straight overhead. Turn the map upside down when looking North.

The larger the blob on the map, the brighter the object will appear in the sky–note the magnitude legend at the bottom right of the map. Contrary to intuition, the higher the magnitude number, the dimmer the object appears.

ISS (International Space Station passes)

Will the ISS make a pass over Chapel Hill tonight?