Amateur astronomy

Amateur astronomy is a hobby centered on observing, studying, or imaging celestial objects. Participants use their eyes, binoculars, telescopes, and various other tools to explore the universe. While scientific research is not always their main goal, many amateurs contribute to citizen science. They monitor phenomena like variable stars, sunspots, and the occultations of stars by the Moon or asteroids. Some even discover transient events, such as comets, galactic novae, or supernovae in distant galaxies.

An amateur astronomer is defined by their relationship to the field. They do not use astronomy as their primary source of income. Most also lack professional degrees in astrophysics or advanced academic training. While some are simple hobbyists, others possess high levels of experience. These advanced amateurs often work alongside professional astronomers to assist with research. Since the early twentieth century, professional astronomy has become a distinct activity from amateur pursuits.

Observers use a wide range of instruments to study the sky. Many start with simple tools like the naked eye or binoculars. Binoculars are portable and offer a wider field of view than many telescopes. For more detail, amateurs use different types of optical telescopes. Reflector telescopes use mirrors to gather light, while refractors use glass lenses. Hybrid telescopes combine both mirrors and lenses for their operation. There are also Dobsonian telescopes, which are a specific type of reflector with a unique mount.

Technology has introduced more sophisticated ways to locate and track objects. GOTO telescopes are computer-driven systems that have become popular since the 1980s. A user enters the name of an object, and the telescope moves to it automatically. This is often faster than the manual method known as star hopping. Some systems use built-in GPS to make setup even quicker. Another tool is the digital setting circle, or DSC. These computers use databases to help users move a telescope to specific coordinates.

History shows that people have studied the sky for thousands of years. Early civilizations, such as the Babylonians, Chaldeans, and Egyptians, used celestial observations for survival. They created calendars and predicted eclipse dates to manage agriculture. In the mid-nineteenth century, the hobby began to grow more popular. Following World War II, equipment became more accessible to the general public. A notable pioneer was Grote Reber, who built the first purpose-built radio telescope in the late 1930s. He followed up on radio wavelength discoveries made by Karl Jansky.

Modern amateur astronomy also includes non-visual and remote methods. Amateur astrophotography uses digital, DSLR, CCD, or CMOS cameras to capture images. Some observers use radio telescopes, including home-made versions or research telescopes like the One-Mile Telescope. Others use remote-controlled telescopes via the internet. This allows an observer to control a telescope in dark locations like Chile, Australia, or New Mexico. Digital data is then transmitted back to the user for imaging and study.

Despite the excitement, observers face challenges like light pollution. This sky glow from cities washes out darkness and reduces visibility. To combat this, many amateurs travel to rural areas for darker skies. They also join astronomical societies for education and guidance. Some practice "sidewalk astronomy," which involves setting up telescopes for public viewing. This helps educate the public and raises awareness about the importance of dark skies.