General Interest

(This article originally appeared in the Q3 1995 STAR newsletter and was written by Greg Gittings. -I) Polarization of the Sky – A Daytime Test for Transparency A Short History by Greg Gittings Looking at the northern or southern polar section of the sky with an analyzer (a pair of Polaroid sunglasses will do) can tell you if the atmosphere is dry or humid in the upper levels. Dry air is highly polarized and it becomes almost blue-black in the…

(This article originally appeared in the Q4 1991 STAR newsletter.) Chemistry of an Interstellar Cloud by Mike Albers Chemical reactions between hydrogen, carbon and other atoms in interstellar clouds form molecules. Moving in random paths, atoms must collide with other atoms before a chemical reaction takes place. The more atoms in a volume of space, the more collisions and chemical reactions. Thus, cloud density affects the reaction rate, giving dense cores in a GMC an advantage over the rest of…

(This article originally appeared in the Q3 1991 STAR newsletter.) Forming Type OB Stars by Mike Albers< Small stars (less than 10 solar masses) form throughout a giant molecular cloud (GMC). The really big hot stars, type B2 and up, containing over 10 solar masses, form through a different route. These stars can't form in the small cores located throughout the cloud; fragmentation breaks these cores into too small of pieces. Instead, large stars form in large dense clumps at…

(This article originally appeared in a 1990’s STAR newsletter.) Clyde Tombaugh’s Pluto By Sean League At four o’clock on 18 February 1930 an unbelievable amount of patience and effort paid off. A new planet was discovered. The planet, Pluto, was at last discovered by Clyde Tombaugh. Clyde Tombaugh was born on 4 February 1906 on a farm near Streator, Illinois. He had four brothers and sisters, all of which were younger. Clyde and his family often visited his Uncle Lee…

(This article originally appeared in the fourth quarter 1990 STAR Newsletter. Also references to BC and AD changed to the modern versions BCE/CE) Origin of Julian Days by David Williams One of the most ancient uses of astronomy was timekeeping. In every civilization, the motions of the Moon and Earth were used to calculate the time and the date. In ancient Greece, each community kept a separate calendar, and all were based on the lunar cycle. The earliest Roman calendars…

(This article originally appeared in the Q4 1988 STAR news letter.) Timing Occultations By Mark Lang Observing an occultation is both exciting and scientifically valuable. I would like to get more RAC members active in observing occultations, so hopefully this article will show those who haven’t tried one how easy it can be. Weather permitting, observers can time several more occultations this year. The most common type of occultation is a total lunar occultation. The Moon, in it’s eastward motion…

(This article originally appeared in the Q3 1987 star news letter) The Great Attractor by David Moore In the early part of this century, V. M. Slipher and later Edwin P. Hubble measured displacements of spectral lines in the light from other galaxies. Such shifts reflect the Doppler effect: the change in the wavelength of radiation or sound that results from motion of the source with respect to the observer. Most of the galaxies showed a red shift, meaning that…

(This aritcle originally appeared in the Q2 1987 STAR news letter) WHERE IS THE EYEPIECE ON A RADIO TELESCOPE? Radio Astronomy is the study of extraterrestrial radio signals reaching Earth. It is similar to optical astronomy in that both involve the study of electromagnetic energy. While optical astronomy deals with very short wavelengths of fractions of an inch, radio astronomy deals with wavelengths that may be 10 feet! The major instrument in the science of radio astronomy is the radio…

(This article originally appeared in the Q2 1985 STAR Newsletter and was written by Bob Thornburg.  Incidentally, the Jordan Lake experience is why RAC does not post directions to our observing site.) Halley’s Comet Experience On Friday January 10, we had a public observing night for Halley’s Comet. The weather started out as a good clear night. This event was heavily publicized on radio and television, so we expected up to 1,000 people might attend. We were all shocked to…

This article originally appeared in the second quarter 1985 STAR Newsletter and described RAC’s Astronomy Days in 1985.  This was done at Crabtree Valley Mall, unlike today’s venue at the NC Museum of Natural Sciences.  This shows how far we have come in the last 20 years and how, even though some things are the same, a lot has changed.  However, it’s still interesting to occasionally look back. Enthusiasm turned Astronomy “day” into “days” which were celebrated April 27th &…

First Year in Amateur Astronomy (early spring 2007-2008) So, I’ve been at it for more than year now, and what I have seen and learned is astounding.  From a historical account I have always been interested in the cosmos since I was a single digit old, and took the boyhood dream of wanting to become an astronaut.  Now, I may be no astronaut but I do have a decent income.  It then hit me in the head, “Why don’t I…

There has been a lot of discussion in the news regarding green laser pointers.  The great concern recently has been that a terrorist might attempt to cause aircraft to crash by spotting one with a laser.  This seemed ridiculous to me for a number of reasons, but because laser pointers are so commonly used by the amateur astronomy community (including myself), I wanted to understand the facts better.  The following is what I found.