Astronomy:Alpha Capricornids

Alpha Capricornids
Celestial map of Capricornus
Discovery date	1871
Parent body	169P/NEAT (2002 EX12)
Radiant
Constellation	Capricornus
Right ascension	20h 44m 00s
Declination	−10° 00′ 00″
Properties
Occurs during	July 7 to August 15
Date of peak	July 31
Velocity	23 km/s
Zenithal hourly rate	5

Alpha Capricornids is a meteor shower that takes place as early as 7 July and continues until around 15 August. The meteor shower was discovered by Hungarian astronomer Miklos von Konkoly-Thege in 1871. This shower has infrequent but relatively bright meteors, with some fireballs. Parent body is comet 169P/NEAT.

Peter Jenniskens and Jeremie Vaubaillon identified the parent body as asteroid 2002 EX12, which in the return of 2005 was found weakly active near perihelion. This object is now called comet 169P/NEAT.

According to Jenniskens and Vaubaillon, the meteor shower was created about 3,500 to 5,000 years ago, when about half of the parent body disintegrated and fell into dust. The dust cloud evolved into Earth's orbit recently, causing a shower with peak rates of 2-5/h, sometimes having outbursts of bright flaring meteors with rates up to 5-9/h.

The bulk of the dust will not be in Earth's path until the 24th century. The Alpha Capricornids are expected to become a major annual storm in 2220–2420 A.D., one that will be "stronger than any current annual shower."

External links

• Interactive visualization of Alpha Capricornids meteor stream
• -4 magnitude Alpha Capricornid shooting past Delphinus on July 17, 2006. Sigma 20 mm f/1.8