Astroblog: The 2018 Australian Lyrid Meteor Shower, Morning 23 April

Wednesday, April 18, 2018

The 2018 Australian Lyrid Meteor Shower, Morning 23 April

The morning sky looking north as seen from Brisbane at 5:00 am AEST on April 23. The Lyrid radiant is marked with a starburst. It is quite close to the obvious bright star Vega low above the northern horizon.

Similar views will be seen elsewhere at an equivalent local time. The radiant will be higher in northern Australia, and lower in southern Australia (click to embiggen).

The Lyrids, the debris of comet C/1861 G1 (Thatcher) are a weak but reliable shower that occurs every year between April 16- April 25, with the peak this year on April 23 Australian time.

That's around 10 am 23 April in east coast Australia, the radiant doesn't rise until 1 am on the 23rd, so the best time to view the Lyrids in Australia is from 4 am on the 23rd.

The predicted ZHR this year is 18 meteors per hour. the number of meteors you could expect to see if the radiant (the apparent position where the meteors originate) was at the highest point of the sky, under dark sky conditions. Under ideal conditions, you will see a meteor on average about once every three minutes. This can be as interesting as watching paint dry. Also, while that meteor every three minutes is the average, meteors are like buses, you wait for ages and then a whole bunch turn up. In Australia, the rate is much less.

Under real conditions the Lyrids radiant will not rise to the zenith from most places, and most places won't have really dark skies. The lower the radiant is, the thicker atmosphere will obscure the fainter meteors, and some of the meteors will start to "burn" below the horizon, so over all you will see fewer.

This is particularly true in Australia, where the radiant is very low to the northern horizon. In Australia the radiant rises about 1 am local time, but it is not really high enough for there to be any real chance of seeing meteors until around 4 am, when the radiant is between three hand-spans to four hand-spans above the horizon (see diagram above). The Moon has long set, so Moonlight is not a factor this year.

From Australia, at 4 am, under dark sky conditions, we will see between 4 meteors per hour (southern states) to 6-8 meteors per hour (Northern Territory and QLD).

If you want to see what the rates will be like at your area, try the Meteor Flux Estimator. The illustration shows the output for dark sky sites in Brisbane.

Unfortunately, both Chrome and Firefox have changed their security settings to prevent plugins from running, and the flux estimator only runs under Internet Explorer now.

Choose 6 April Lyrids from the drop down meteor shower Menu, the date (make sure that you set the year to 2015, and your location, most people will have to put in their latitude and longitude (strangely, Adelaide, Brisbane, Darwin and Perth are listed in the drop down menu, but Sydney, Melbourne and Hobart are not) under "other" in the location box.

This will give you a chart of the numbers of meteors per hour you can expect at various times (see image to the left).

The Lyrids are pretty poor in Australia, but if you are patient you may see the occasional meteor shooting up from below the horizon.

Labels: Meteors

# posted by Ian Musgrave @ 5:50 pm

Comments:

Thanks for that info. A friend of mine saw some shooting stars last night which reminded me of this event, but there were very little Australian info on the Net in regards to when, where and which part of the sky to look at.

# posted by