Tuesday, 8 August 2023

Perseid Meteor Shower

 This page was last modified on Tue. Aug 15, 2023

The modification was

An Umbrella of Meteors or a Summary of Perseids

 Previous modification(s) :

Field Notes from Afar Alvar


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This blog is http://rhapsodieswiseoldbird.blogspot.com/2023/08/perseid-meteor-shower.html

Perseid Meteor Shower

 What is:

 Perseid adj, Perseus- a group of stars, rising in the north-east     at dusk in August - below the brighter "W" of Cassiopeia
    Go to Wikipedia for more description; e.g., Wiki Perseids 

 Meteor    or shooting star: a dust grain which is heated to incandescence by the Earth's atmosphere and glows until it has vaporized.
    It is interesting that the ancients associated this phenomenon with the Earth's atmosphere and not with something in space.
    https://en.wikipedia.org/wiki/Meteor_(disambiguation)

Shower  here as in a "meteor shower" and not rain -  occurs when the Earth passes through the trail of debris left by a comet or asteroid.


So the Perseid Meteor shower is caused by the particles left from the Comet Swift-Tuttle, entering the Earth's atmosphere at high speeds and glowing until evaporation ends.

Actually it is one of 3 occurring at nearly the same time (mid July to mid August): Kappa Cyg and the Delta Aqu are the other 2  - more below.

When is the Perseid Shower
In 2023 the Perseid meteor shower is active between 17 July and 24 August, with the number of meteors increasing every night until it reaches a peak in mid-August, after which it decreases. This year the peak falls on the night of the 12th/13th August. (Sat-Sun)


( Weather forecast: - currently favours Friday evening/Saturday morning.)

Be aware of heavy dew during the night.


New Moon is on Wed Aug 16

Where is the Perseid shower
If one can locate the band of stars overhead called the Milky Way then the sky is probably dark enough to observe. Follow the band to the left toward the North-East horizon. Find a "W" on its side, Casseopeia, just above the radiant, the point on the sky from which the shooting stars appear to start.

How to observe it
One does not look at the radiant! Rather one looks to a side with the least obstruction from trees, buildings, lighting, horizon, etc. Pick something "prominent" and observes in this vicinity during the night. As the Earth rotates, this area of sky will appear to move westward. Relax and enjoy the view.
https://www.astronomy.com/observing/how-to-observe-a-meteor-shower/

Of course, if you want a "pretty picture" of a shooting star through the Big Dipper, or the Cass "W" or M31, you will have to take photos of that particular patch of sky.
If you choose the Big Square of Pegasus you might catch trails from all 3 showers as well as random sporadics.

I wanted to catch a meteor near the Pleiades one year.

The first night after 2 dozen photos I had this one:


On the next night after over 100 shots - nothing! I wish everyone clear skies and good luck.


What causes it, the shower?
Comet Swift-Tuttle (109P/Swift-Tuttle), a comet that takes 133 years to orbit the Sun, is the parent body of the, at times, epic Perseid meteor shower. It was first recorded
in August of 36 CE by Chinese astronomers, but credit for its modern identification is given to Adolphe Quetelet in 1835. Its meteors are visible from July 13 to August 26.

Some History
The comet
https://en.wikipedia.org/wiki/Comet_Swift%E2%80%93Tuttle

Messier
https://en.wikipedia.org/wiki/Charles_Messier

St Lawrence's tears
https://www.natureupnorth.org/justmynature/jrmiller/tears-st-lawrence

K-Cygnid meteor shower .
https://en.wikipedia.org/wiki/Kappa_Cygnids
(Vicki and I discovered this on our own in 2013 and 2014. It may be related to a Near-Earth Asteroid.)

Delta Aquariid meteor shower
https://www.rmg.co.uk/stories/topics/delta-aquariid-meteor-shower-2023-when-where-see-it-uk
(another shower with an uncertain - for us! -  progenitor)

Saturn - this year/2023 it is not far from the radiant for the Delta Aquariids. In other years
the radiant is to be found by locating the west side of the "square of Pegasus" and following it down to
the only bright star, Formalaut. The radiant is about half that distance - where Saturn was located in August 2023.

https://earthsky.org/astronomy-essentials/saturn-at-opposition-closest-brightest-best/
https://earthsky.org/tonight/saturns-opposition-fun-things-to-see
https://www.astronomy.com/observing/see-saturns-rings-at-their-finest/ 2022 and closing

And maybe add an aurora alert?

 
References:
https://www.space.com/32868-perseid-meteor-shower-guide.
 This gives meteor counts in near real time to date/hour
https://www.imo.net/resources/faq/ Frequently Asked Questions on Visual Observations
Frequently Asked Questions on Photographic Observations  - is given near the end of the link-

WOB

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