The Gamma Normids (GNO) are a weak

meteor shower A meteor shower is a celestial event in which a number of meteors are observed to radiate, or originate, from one point in the night sky. These meteors are caused by streams of cosmic debris called meteoroids entering Earth's atmosphere at ext ...

, active from March 7 to 23, peaking on March 15. The radiant is located near the star

Gamma2 Normae Gamma2 Normae, Latinized from γ2 Nor, is the brightest star in the southern constellation of Norma. Its apparent magnitude is 4.02 – making it a faint star but visible to the naked eye. Based upon an annual parallax shift of 23.57&n ...

in the constellation

Norma Norma may refer to: * Norma (given name), a given name (including a list of people with the name) ** Norma Lizbeth Ramos, a Mexican bullying victim Astronomy *Norma (constellation) * 555 Norma, a minor asteroid * Cygnus Arm or Norma Arm, a spiral ...

History

The first observations were made by R A McIntosh from

Auckland Auckland ( ; ) is a large metropolitan city in the North Island of New Zealand. It has an urban population of about It is located in the greater Auckland Region, the area governed by Auckland Council, which includes outlying rural areas and ...

New Zealand New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...

in 1929, with confirmation coming from observations made by M. Geddes in 1932. The shower was virtually ignored until

radar Radar is a system that uses radio waves to determine the distance ('' ranging''), direction ( azimuth and elevation angles), and radial velocity of objects relative to the site. It is a radiodetermination method used to detect and track ...

equipment used by A A Weiss in

Adelaide Adelaide ( , ; ) is the list of Australian capital cities, capital and most populous city of South Australia, as well as the list of cities in Australia by population, fifth-most populous city in Australia. The name "Adelaide" may refer to ei ...

South Australia South Australia (commonly abbreviated as SA) is a States and territories of Australia, state in the southern central part of Australia. With a total land area of , it is the fourth-largest of Australia's states and territories by area, which in ...

detected activity 15–16 March 1953. An attempt to observe the shower with radar in 1956 was unsuccessful, however the shower was observed again with radar in 1969. Members of the Western Australia Meteor Section made extensive observations in the 1970s and 1980s. In 1983 the average magnitude of the 63 meteors was 2.68 and 9.5% had trains with the highest

Zenithal Hourly Rate In astronomy, the zenithal hourly rate (ZHR) of a meteor shower is the number of meteors a single observer would see in an hour of peak activity if the radiant was at the zenith, assuming the seeing conditions are perfect (when and where stars w ...

(ZHR) of 9.6±2.3 recorded on the night of March 13/14 . In 1986 273 meteors were observed, and the highest ZHR (3.49) was recorded on March 14/15. Nearly 20% of the meteors left trains. In 2005 the Liga IberoAmericana De Astronomía noted meteors from this stream every night during the observation period of March 8–17. The highest number of meteors seen was 5, on the night of March 10/11 with a ZHR of 14 ± 6.

References

{{reflist Meteor showers March