Tuesday, April 21, 2009

April Showers

After a pretty quiet first quarter of the year, meteor shower activity starts in earnest in April. There are three meteor showers occurring even now: The Lyrids, the Pi Puppids and the Eta Aquarids. I will be concentrating on the first two meteor showers here and will leave the Eta Aquarids for a later post.

The Lyrids

The Lyrids meteor shower starts on 16th April and remains active until 25th April. The peak activity date for this shower is in the morning of Wednesday 22nd April.

The Lyrids is the oldest documented meteor shower known to astronomers. This is probably because it is one of the best meteor showers seen from the northern hemisphere, especially from the European, Middle Eastern and Chinese regions. However it is not quite as impressive to the observers located in Male' as such meteor showers as the Orionids or the Perseids. This is mainly because Lyrid meteors appear to stream from the bright star Vega in the constellation Lyra (which is located north of Male' and hence very much dimmed because of the immense light pollution coming from the street lights of Male' as well as those of Hulhule' and the resorts and marine vessels). Vega rises from the north-east around 10:15 pm these days and will be highest in the sky sometime around 4:30 am almost straight up north at about 60° latitude. Folks in other islands will probably be able to view the Lyrid meteor shower much better than us here in Male'.

Lyrid meteors tend to be very bright and sometimes leave behind smokey debris trails that linger for minutes.

Vega is an interesting star on its own. It is about 25.3 light years away and has a luminosity of 73 suns. Although we all now know Polaris as the North Star (the star that always points to the celestial north), it wasn't always so. About 14,000 years ago Vega was the North Star. It will once again become the North Star 12,000 years later. This is because Earth's spin axis wanders causing its orientation to change over time. Those who watched Carl Sagan's movie 'Contact' would also remember that Vega was the source of the aline transmisson to Earth in the movie.

The Pi Puppids

The Puppids meteor shower starts on 19th April and remains active until 28th April. It peaks on 23rd April.

Looking south-west after sunset on 23rd April

The Puppids radiant (the point in the sky from which meteors appear to originate) lies in the constellation Puppis, the Poop Deck. Once again its not an ideal meteor shower for observers in Male' because of its proximity to the horizon. However the slow and sometimes bright nature of its meteors may make them a good target for photography. Puppis lies above the horizon when the sun sets during this week and will remain above horizon until about 11:30 pm. The best time to view the showers would be about an hour after the sun sets.


 

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