Amateur astronomers watch the night sky during the Perseids | Perseid meteor shower.

Amateur astronomy is usually associated with viewing the night sky when most celestial objects and events are visible, but sometimes amateur astronomers also operate during the day for events such as sunspots and solar eclipses.

Amateur astronomers often look at the sky using nothing more than their eyes, but common tools for amateur astronomy include portable telescopes and binoculars.

Amateur astronomers also use star charts that, depending on experience and intentions, may range from simple planispheres through to detailed charts of very specific areas of the night sky.

Amateur astronomers often like to keep records of their observations, which usually takes the form of an observing log.

Amateur astronomers engage in many imaging techniques including film and CCD astrophotography.

Amateur astronomers often contribute toward activities such as monitoring the changes in brightness of variable stars and supernovae, helping to track asteroids, and observing occultations to determine both the shape of asteroids and the shape of the terrain on the apparent edge of the Moon as seen from Earth.

Amateur astronomers have made significant contributions to the profession and hobbyists have made discoveries such as a celestial body or celestial event.

Amateur astronomers have contributed to many important astronomical discoveries, and astronomy is one of the few sciences where amateurs can still play an active role, especially in the discovery and observation of transient phenomena.

Amateur astronomers can do useful scientific study of variable stars by visually comparing the star with other stars within the same telescopic field of view of which the magnitudes are known and constant.

Amateur astronomers and amateur telescope makers also use homemade equipment and modified devices.

Category: Amateur astronomers

Category: Amateur astronomers

The International Fellowship of Rotarian Amateur Astronomers ( IFRAA ) is a fellowship group of amateur astronomers which spans the continents.

Category: Amateur astronomers

Amateur astronomers use such instruments as the Newtonian reflector, the Refractor and the increasingly popular Maksutov telescope.

Amateur astronomers tend to refer to telescope eyepieces by their focal length in millimetres.

Category: Amateur astronomers

Category: Amateur astronomers

Category: Amateur astronomers

Category: Amateur astronomers

Amateur astronomers have been successful at discovering Kreutz comets in the data available in real time via the Internet.

During this time the park manager allows amateur astronomers including the Minnesota Amateur Astronomers, MNAA, to use the park and facilities.

Category: Amateur astronomers

Packets radio use the AX. 25 ( Amateur X. 25 ) data link layer protocol, derived from the X. 25 protocol suite and adapted for amateur radio use.

After investigation and a petition to the FCC, Part 12 was amended, in March 1956, to allow Amateur Radio Operators to use any shift that was less than 900 hertz.

The FCC approved the use of ASCII by Amateur Radio stations on March 17, 1980 with speeds up to 300 baud from 3. 5 to 21. 25 MHz and 1200 baud between 28 and 225 MHz.

Amateur radio operators continue to use this mode of communication today.

Organizations known to use ALE for Emergency management, disaster relief, ordinary communication or extraordinary situation response include: Red Cross, FEMA, Disaster Medical Assistance Teams, NATO, Federal Bureau of Investigation, United Nations, AT & T, Civil Air Patrol, SHARES, State of California Emergency Management Agency ( CalEMA ), other US States ' Offices of Emergency Services or Emergency Management Agencies, and Amateur Radio Emergency Service ( ARES ).

Amateur radio operators may use it to call each other for voice or data communications.

International amateur radio ALE High Frequency channels are frequency coordinated with all Regions of the International Amateur Radio Union ( IARU entity of ITU ), for international, regional, national, and local use in the Amateur Radio Service.

All Amateur Radio ALE channels use " USB " Upper Sideband standard.

Hellschreiber is still in use today by Amateur Radio ( Ham ) operators around the world.

Transmitters must be licensed by governments, under a variety of license classes depending on use: ( broadcast, marine radio, Airband, Amateur etc.

The town also has its own tennis club Downpatrick Tennis Club Downpatrick has several other clubs that use the facilities of the Down Leisure Centre ( run by Down District Council ) such as the Lecale Amateur Swimming Club, the Downpatrick School of Lifesaving and the East Down Athletics Club.

Amateur radio enthusiasts primarily use this quality of the ionosphere to help propagate lower frequency HF signals around the world: the waves are trapped, bouncing around in the upper layers of the ionosphere until they are refracted down at another point on the Earth.

Amateur radio ( also, ham radio ) is a form of radio communication that is the private use of designated radio bands, for purposes of private recreation, non-commercial exchange of messages, experimentation, self-training, and emergency communication.

The Tournament of Roses Radio Amateurs ( TORRA ) provided audio communications and video co-ordination for the parade officials through the use of Amateur radio from 1968 until 2005.

The FCC was susequently charged by Congress to conduct a study into the uses and capabilities of Amateur Radio Service communications in emergencies and disaster relief, and into the existence of impediments thereto, including the effects of unreasonable or unnecessary private land use restrictions on residential antenna installations.

The use of duplex radio repeaters and interconnects to the telephone network are prohibited under FRS rules, unlike GMRS and the Amateur Radio Service.

Amateur radio stations in Mexico use XE1 for the central region, XE2 for the northern region, and XE3 for the southern region.

Amateur radio and some cellular or PCS wireless systems use direction finding or triangulation of transmitter signals radiated by the mobile.

Amateur winemakers often use glass carboys in the production of their wine ; these vessels ( sometimes called demijohns ) have a capacity of 4. 5 to 54 liters ( 1. 2 – 14. 3 US gallons ).

* Amateur radio operators often use the number 73 as an abbreviation for " best regards ", typically when ending a QSO ( a conversation with another ham ).