Cygnus Loop Supernova Blast Wave

This is an image of a small portion of the Cygnus Loop supernova remnant, which marks the edge of a bubble-like, expanding blast wave from a colossal stellar explosion, occurring about 15,000 years ago. The HST image shows the structure behind the shock waves, allowing astronomers for the first time to directly compare the actual structure of the shock with theoretical model calculations. A bluish ribbon of light stretching left to right across the picture might be a knot of gas ejected by the supernova; this interstellar "bullet" traveling over three million miles per hour (5 million kilometres) is just catching up with the shock front, which has slowed down by ploughing into interstellar material. The Cygnus Loop appears as a faint ring of glowing gases about three degrees across (six times the diameter of the full Moon), located in the northern constellation, Cygnus the Swan. The photo is a combination of separate images taken in three colors, oxygen atoms (blue) emit light at temperatures of 30,000 to 60,000 degrees Celsius (50,000 to 100,000 degrees Farenheit). Hydrogen atoms (green) arise throughout the region of shocked gas. Sulfur atoms (red) form when the gas cools to around 10,000 degrees Celsius (18,000 degrees Farenheit).                                                                          Image coutesy of NASA

Special Autumn Event: Stella-Della-Valley XXIII

Our Mission

The Bucks-Mont Astronomical Association (BMAA) is a group of amateur astronomers working together to improve astronomical knowledge and observational skills. We make ourselves and our instruments available to promote public interest in astronomy. BMAA members are a varied group of colleagues who share a curiosity about the sky. Some members are scientists or engineers, while others are artists or craftspeople, building contractors or college students. Ability levels span the range from novice to expert. BMAA members organize and participate in a variety of astronomy related programs:

• Monthly Meetings

Members and guest speakers present lectures or demonstrations on astronomical topics, followed by a group observing session. Meetings are held at the Peace Valley Nature Center north of Doylestown, PA.
• StarParties

Members gather at one of several dark-sky sites to help each other hone observing and astrophotography skills.
• StarWatches

StarWatches are conducted at several nature centers. The public is invited for an evening of stargazing and observing tips provided by BMAA members and their telescopes.
• Astronomy Day  An annual event, a day long series of workshops and demonstrations to promote interest in astronomy.
• Stella-Della-Valley

An annual astronomical weekend StarFest in which members and guests participate in workshops, dark-sky observing, bartering of equipment and many other activities.
• Special Programs  BMAA members take part in seminars and educational activities sponsored by the Franklin Institute, the Astronomical League and neighboring astronomy clubs.
• Educational outreach  BMAA is a community resource, offering astronomy programs to schools, youth groups and civic organizations.