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Bringing the Universe to Your Classroom!

Wednesday, April 22, 2015

Methods for Observing the Lyrid Meteor Shower

This month’s Lyrid meteor shower isn't one of the year's strongest displays, and with Moon being in a thin, waxing crescent, it won't offer much competition. As with January’s Quadrantids, the Lyrids put on a fairly brief performance, and this year the predicted peak on April 22nd at 23:00 UT.

Lyrid meteor photographed back in the 2012 shower
Lyrid meteor photographed back in the 2012 shower

The Lyrid meteors appear to radiate from a location near the Hercules-Lyra border, which is high in the sky from about 11 p.m. until dawn. The Lyrid meteor shower has been observed for more than 2,000 years; Chinese records say "stars fell like rain" during the shower of 687 BC. But in recent times, the Lyrids have generally been weak, though at intervals of about 12 years the shower occasionally delivers up to 10 times more meteors than normal. The Lyrids did show a brief surge to a Zenith Hourly Rate of 90 back in 1982, but a spike like that has not been reported in any of the Lyrid's since.

Here are a few methods on how to record the Lyrid meteors...

Visual Meteor Observing - An easy way to observe meteors visually is known as the "'counting method". An observer notes the meteors seen on a tape recorder or just a piece of paper. He or she gives the estimated magnitude of the meteor and whether or not it belonged to the observed shower (e.g. Lyrid or non-Lyrid). This method is most applicable for major showers like the Quadrantids, Perseids, and Geminids. You have to decide which observing method, plotting or counting, can be used most favorably. Personally, my preferred method of recording meteors is photocopying a page from a star atlas that includes the shower's radiant and when a meteor is spotted, I would then draw an arrow on the photocopied page of the star atlas pointing in the direction I saw the meteor moving in across the sky. The length of the arrow represented how far it traveled.


Recording meteors on a star atlas
Recording meteors on a star atlas

Photographing Meteors - The first thing you have to have if you want to capture a meteor in a photograph is a camera capable of doing so. I realize there are still folks who use film cameras but the cost and effort of using film to shoot meteors is too great to include as a method, therefore, I will recommend just on digital. However, when I did use film years ago, I used a Pentax K1000 camera and use during meteor showers for long exposures.

There are a lot of digital cameras out there capable of capturing excellent images of meteors. It is possible to catch a meteor on nearly any camera that allows for manual or semi-manual control and exposures of at least 15 seconds. Once you have your camera there are several other things you really need to have.

1. Sturdy tripod - No images shot during dark/dusk or in any low light condition will work without it. 

2. Cable release - You don't want to be hovering over your camera all night with your finger pressed on the shutter and if you did your photographs wouldn't be as good as they could have been b/c you will cause a slight movement every time you touch the camera. Some cable release cords have settings that allow exposure length (bulb) to be specified which is a big help. 

3. AC adapter or several batteries - Most digital SLR cameras have AC adapters available but if not several batteries should do the trick.

4. Memory cards - More than likely you will be taking lots of pictures in attempting to catch a meteor so make sure you have enough memory. An 8 GB card should be good for all night. A 4 GB card should work if your exposures are longer (1-2 mins). Another option is connecting your camera to a computer and controlling it via the computer and having the images saved directly to your computer. The down-side here is that a slight delay between shots (1-3 seconds) could cause the observer to miss something.
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Saturday, April 11, 2015

The March 2015 Solar Eclipse

When I heard that March 20, 2015, the total solar eclipse would be visible as a partial solar eclipse from Krakow, Poland, I had a dilemma: how can I observe this event when I possessed no adequate filter to protect my camera so I could photograph it? In the past, I used to own a specialized solar filter made from mylar, and so I thought: what do I have now that has such a similar property? 

The author's image of March 20, 2015  Solar Eclipse visible from Krakow, Poland.
The author's image of March 20, 2015
Solar Eclipse visible from Krakow, Poland.

The answer was remarkably simple: a blank DVD. Luckily I possessed a blank DVD with no artwork on the top that might diffuse the sun's image, and with my (cell phone) camera I went out and captured the eclipse in a matter of minutes. Please click on the image to enlarge to see the eclipse in more detail.

WARNING: Even though my plan was to photograph the eclipse through the DVD using my cell phone camera, you should NEVER use a CD/DVD/Bluray disk as a filter to look directly at the sun with your eyes: invisible radiation may get through the improvised filter and damage them! So please be careful trying this method to photograph a solar eclipse!

Some interesting facts about this solar eclipse:

It so happened that this solar eclipse occurred that same date as the 2015 March equinox (the moon turned new only 14 hours after reaching lunar perigee) moon’s closest point to Earth in its orbit. Thus this moon was a "Supermoon" – at the new phase – not visible in our sky, but having a larger-than-average effect on Earth’s oceans. Plus this new "Supermoon" swung right in front of the equinox sun on March 20, so that the moon’s shadow fell on parts of Earth.

Who was able to view the March 20 eclipse?:

In other words, only those along that path (at high northern latitudes, near Greenland and Iceland) were able to observe the total eclipse. The path of totality started at sunrise to the south of Greenland, circled to the east of Greenland and Iceland during midday, and ended to the north of Greenland at sunset. The best spot to watch this total solar eclipse from land was the Faroe Islands and the Svalbard archipelago, which reside right on the semi-circle path of totality.
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