2020 Lyrids Meteor Shower

 

The annual Lyrids meteor shower is underway with peak activity on the evening of April 21st.  With no Moon to spoil the party conditions will be ideal for observing them this year assuming those pesky clouds stay away.  The best times to view the shower are as late as possible, close to midnight or in pre-dawn skies when the Lyra radiant is at its greatest elevation.  However, you don’t need to look at the radiant to see shooting stars as they’ll appear to come from all directions.

What Causes a Meteor Shower

Meteors are the fine dust and particulates left over from comets and large asteroids which stray into our solar system.  Some of these are on predictable orbits and as they whizz around the Sun they melt and shed some of their material into space.  The Earth then travels through these large dust trails as it orbits the Sun, producing predictable meteor showers.  The Lyrids are generated by Comet Thatcher, which has a 415 year orbit.

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Observing the Lyrids

You don’t need any special equipment to view a meteor shower, in fact binoculars or telescopes will just narrow your field of view. Grab a deck chair or camping mat and (if it’s cold) a warm blanket, prepare a hot drink and lay out under the darkest conditions you can find. It’s an excellent activity to do alone, with family and friends, or if you have children they’ll love an excuse to get outside for some after dark play.

Put away any lights or bright mobile phone screens and simply look up and wait. Remember it takes up to 30 minutes for your eyes to fully dark adapt and any exposure to bright lights will start the process all over again. If you need a light, red LEDs or touches are best for preserving you night vision.

For optimal viewing, head out late at night or in the darkness of the pre dawn sky., when the radiant is highest in the sky.

Don’t Expect Too Much

You need to be patient with meteor showers.  Sometimes you’ll see many and other times very few or none at all.  Think of it as a great excuse to get out under the stars and breath in some fresh air.  Even if you don’t see much you probably won’t regret heading out and looking up.  Very rarely meteor showers can erupt into storms, like the Leonids in 1833 when over 100,000 shooting stars criss crossed the night sky.

Photographing the Lyrids

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If your have a DSLR camera and tripod, or a suitable phone app like NightCap, you could try capturing some meteors with this rough guide.

  1. Firmly attach your camera or phone to the tripod.
  2. Disable autofocus and manually focus on some bright stars (make them as small and pin point as possible in your viewing screen)
  3. Set an ISO range somewhere between 1000-3000 depending on the capabilities of the sensor.  Mid 1000s is a good middle road.
  4. Turn off noise reduction or you’ll get big delays between each shot.
  5. Point your camera at a high and clear part of the sky.
  6. Shoot long exposures ranging from 10s to 30s, or simply use a remote shutter to take long manual exposures.  Note:  don’t go crazy with very long exposures or you’ll get amp glow from the sensor.
  7. Take lots and lots of shots and be patient!

If your camera has a time-lapse feature you can automate the shooting process and tell the camera to continually shoot 30 second exposures over a long interval.  Just watch out for dew forming on the lens if conditions are cold.  Some hand warmers stuffed into a sock wrapped around the lens will solve this particular issue.

Good luck and clear skies!

Ursa Major Video Guide

 

My video stargazing guide to the constellation Ursa Major, known to stargazers and astronomers in the northern hemisphere by its famous asterism of the Plough or Big Dipper.

Many thanks to Rising Galaxy of Cosmicleaf Records for gifting the background music to this piece. If you like drone ambient or cosmic chill out music please check out their web stores for more of the same.

Clear skies.

The Astronomy of Ancient Places (Livestream talk)

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In view of recent developments my contribution to this years Inverness Science Festival will be a free live streamed talk.  Please visit my Highland Astronomy facebook page for more details:

Astronomer Stephen Mackintosh will take you back in time to discover how our distant ancestors used the Sun, Moon and stars to track the progress of time and the seasons. Looking at ancient monuments connected to the night sky, we’ll go on a tour of Egypt, Central America, southern England and back home to Scotland where some of the finest concentrations of neolithic structures exist anywhere in Europe, not least the wonderful Clava Cairns. Plus advice on sky watching and naked eye observing you can put into practice yourself.

Note: this event is free and will be live streamed online as part of the Inverness Science Festival’s adjusted programme.

Stephen Mackintosh’s blog: modulouniverse.com
Image by Callanish Digital Design: callanishdigitaldesign.com

Covid-19 Infection Rates

I wanted to do my bit to highlight the need to socially distance at the moment. In addition to outreach astronomy I’ve worked as a mathematical modeller and simulation programmer for many years. Yesterday I decided to create a very simple demonstration to show how infectious Covid-19 is relative to something like the flu.

The red balls represent new cases of Covid-19 based on one individual passing the virus on and creating a human chain reaction. The blue balls represent the same situation for flu. The simulation shows you how many more people will become infected with Covid-19 relative to flu after the same number of transmission waves (9 in this case).

Typically an individual with flu will pass the virus onto 1.3 other people (called the R0 value). With Covid 19 this spreading rate is much higher – between 2.3 and 3. At its worst therefore an infected person will pass the virus onto 3 other people. That might not sound like much but due to exponential growth this level of transmission is like a bomb going off.

Stay safe everyone and please heed the guidelines. With proper social distancing the cascade on the right can be repressed.

Note: This simulation is not validated in any way by medical experts and is for illustrative purposes only.

Developed by S Mackintosh (Mackintosh Modelling & Data Simulations)
modulouniverse.com

 

‘Not too hot and not too cold’

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The Goldilocks zone around three different type of stars

The Goldilocks Zone.  The above image is a great illustration of the relative size of the habitable zone around different types of star, with stars like our Sun at the bottom.

Even very dim M class dwarf stars (pictured top) could harbour planets with liquid water – the planets would just need to be situated much closer in. These stars can have very active magnetic fields however, frequently throwing harmful radiation out towards any orbiting planets.  M class stars are also extremely stable, some destined to burn for over 100 billions years, much longer than our Sun which has around 4 billion years of fuel left.

In the middle we see the K class dwarf stars. These will also out live our Sun (by a factor of 4), have nice wide zones of habitation, and much less magnetic activity than the M class stars.  Potentially these K class stars are the ideal incubators for the slow evolution of life, and there’s plenty of them. Nearly 13% of stars in our galaxy are K class red dwarfs.  That’s approximately 26 billion in our galaxy alone! 

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An artist’s impression of a rocky world orbiting a red dwarf star, like the M and K class stars mentioned above.

Sirius the Glitter-ball

 

A video of Sirius (the brightest star in the night sky) twinkling on the horizon, captured by Steve Brown @sjb_astro. Many people think they’re seeing a low altitude aircraft or UFO when they witness this.

This phenomenon occurs (to a lesser extent) with any bright star low on the horizon due to the vast amount of atmosphere you’re seeing it through. As stars gain elevation, and less atmosphere is between us and them, they shine more steadily, and views are hugely improved.

The difference in the amount of atmosphere you look through with elevation is very striking (as demonstrated in the sketch below).  Particularly for faint deep sky objects like galaxies, high elevations makes a dramatic difference to the quality of visual or photographic images you’ll collect.

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How much atmosphere you look through with observing angle.  At the zenith (overhead) you look through over 2/3 less atmosphere than at the horizon.