Behlen Observatory public nights resume Sept. 21

            The University of Nebraska-Lincoln's Behlen Observatory near Mead will be open to the public from 7:30 to 10 p.m. on Sept. 21.

            Provided the sky is clear, visitors will be able to view a variety of objects with the observatory's 30-inch telescope and with smaller telescopes set up outside of the observatory. These include the moon, the planet Neptune, two kinds of star clusters, double or multiple stars, and the Ring Nebula in Lyra. At 8 p.m., a member of the observatory staff will give a talk about objects that are currently visible in the evening sky.

            One of the highlights of the autumn sky is the Ring Nebula in the constellation Lyra. Viewed in the 30-inch telescope it resembles a pale smoke ring. It is one of the best and most easily observed examples of a type of object known as planetary nebulae. This object is the remnant of an old, dying star which expelled its outer layers several thousand years ago. They now form a cloud about thee light years in diameter around the star. Due to its extremely high surface temperature -- about 225,000 degrees Fahrenheit -- the star emits intense ultraviolet radiation that heats the gas cloud to a temperature of around 17,000 degrees, causing it to glow. By comparison, the surface of the sun is about 10,340 degrees Fahrenheit.

            This is the first public night of the fall semester. The observatory will also be open to the public from 7:30 to 10 p.m. on Oct. 19 and Nov. 16.

            There is no admission charge for the public night. Further information can be found on the

observatory website at http://astro.unl.edu/observatory/ or by calling Professor Edward Schmidt at

402-472-2788. Directions to the observatory can be found at the website.

Writer: Edward Schmidt