Lyrids

The Lyrids (also April Lyrids ) are an emerging every spring meteor shower, known before our era, for several centuries. The name is derived from the constellation Lyra from (Latin lyra, from ancient Greek λύρα ), the ancient plucked instrument lyre.

As with all other swarms of shooting stars is the best time of observation of the Lyrids in the morning sky, but are individual meteors to see because of the already standing high above the horizon radians already after midnight.

Radiant and phenomenology

The radiant of the April 16 to 25 active Lyrids is located in the southwestern region of the constellation Lyra, approximately 10 ° to the right below the bright white main star Vega. On the day of the very sharp peak ( April 22), the Lyrids have seemingly come from a point to the right ascension of 18h 04m and declination of 34 °. The 5 ° by measuring Radiant shifts daily at 1.1 ° to the east - to the extent to which the orbit of the comet origin is curved.

The maximum number of relatively rapidly flying meteors ( Zenithal hourly rate ZHR ) is on April 22, about 18 per hour, but is hardly achieved in our latitudes.

History

The first recorded observation of the Lyrids dates back to 687 BC from the Chinese historical work Zuozhuan. Chinese observers reported that stars fell like rain from the sky.

Nowadays, the ZHR of the Lyrids is 18 meteors per hour, however, there are irregular activity increases. In the last activity increase in 1982 90 meteors per hour were observed. For a few minutes, rates between 180 and 300 meteors per hour were recorded. Another significant outbreak dates back to 1922, when 100 meteors were seen per hour.

The parent body of the comet C/1861 G1 ( Thatcher ), the required 415 years for one orbit around the sun.

Over the decades, the Radiant seems to shift slightly, probably as a result of disturbances of the comet orbit. Cuno Hoffmeister ( Sonnenberg ) certain radians around 1940 at the site 18:12 / 35 °.

Another origin of comets ( C/1983 H1 ), however, have weak Eta Lyrids that come two weeks later from a 10 ° east lying radians.