Solar Bang

For astronomers, close binary star system BD+20 307 originally stood out because it is extremely dusty. A substantial amount of warm dust surrounding it causes the system to appear exceptionally bright at infrared wavelengths. Of course, dust associated with planet formation is often detected around young stars, stars only a few million years old. But the BD+20 307 system has now been found to be at least a few billion years old, an age comparable to the age of our own Solar System.

The large amount of warm dust is likely the debris from a relatively recent collision of planet-sized objects on the scale of, say, Earth and Venus, in the BD+20 307 system.

Reminiscent of the classic sci-fi novel When Worlds Collide, the dramatic illustration offers a depiction of the catastrophic event. Ironically, this indirect evidence of a destructive planetary collision could also be the first indication that planetary systems can form around close binary stars. BD+20 307 is about 300 light-years distant toward the headstrong constellation Aries.

On September 7th, the first quarter Moon and passing clouds contributed to a dramatic night sky over the Byurakan Astrophysical Observatory. This panoramic view begins at the left looking toward the eastern horizon and the rising stars of the constellation Perseus.

Sweeping your gaze to the right (south), you’ll find the large observatory dome, housing a 2.6 meter diameter telescope, backlit by lights from nearby Yerevan, capital city of Armenia. Fittingly poised above the observatory dome is the bright, giant star Enif in the high-flying constellation Pegasus. Farther to the right, the brightest celestial beacon just above the clouds is our Solar System’s ruling gas giant Jupiter.

At the far right, the Moon is nearly hidden by an approaching cloudbank, but the clouds themselves actually cast shadows in the bright moonlight, creating the effect of Moon rays across the evening sky.