Information about the northern lights

Some calls coming in to the Observatory at Dunsink about the aurora so I'll post a few links here and enquiries can be pointed to this thread.

As people have said before, the best option is get to a dark site if you want to really have the best views of the aurora and also capture the display on camera without any light pollution.

Around Dublin you might find some spots northwest or north of the City ... I've pulled in on the Walshestown road just off the first exit for Balbriggan on the M1 north and got good views of the aurora before at that spot. There's not much room for more than a couple of cars though. The Naul might be good too and also Bective Abbey near Trim which has a large car park. The Sugar Loaf car park or other areas nearby might not be too bad either even though you are looking over the City. If the display is really active you can get good views of it from there despite the capital's light pollution ... it kind of depends on whether there's a lot of haze/aerosols in the atmosphere scattering Dublin's light dome (I noticed a lot of scattering last night despite the sky being clear).

Aurorawatch UK have a magnetometer hooked up to the internet which is worth checking for enhanced aurora activity. See aurorawatch.lancs.ac.uk/ and also aurorawatch.lancs.ac.uk/introduction for an explanation of what is the aurora. The page aurorawatch.lancs.ac.uk/livedata explains how to interpret the magnetometer data. I noticed the example uses the aurora storm of April 6th, 2000 which a few of us actually first noticed from Kenilworth Square in Harold's Cross, just 2 miles or so from Dublin City Centre! It first appeared as two red beams like searchlights shooting up from the northern skyline. A high pale green arch was also visible at this time too. The display was even more spectacular once we got out to Kilakee where the sky was much darker.

Another excellent site is www.spaceweather.com which has lots of information about the latest celestial events. A diagram on the left-hand side of the page shows the current auroral oval as well as details about possible aurora activity.

A similar page with graphic displays of the aurora oval is www.swpc.noaa.gov/ovation/ ... see also their pages on what is the aurora and how to view it.

www.aurora-service.eu/ is another good site with lots of information on the northern lights and how to view it, as is www.gi.alaska.edu/AuroraForecast

Atmospheric optics expert Les Cowley has a few pages on the northern lights at www.atoptics.co.uk/highsky/auror1.htm ... it is well worth looking through the other phenomena highlighted such as halos, etc ... you'll be amazed at the wonders in our sky!

For the more serious observers you can find a bewildering amount of information at www.solarham.net/ and also see the latest space weather alerts/forecasts at www.swpc.noaa.gov/forecast.html

Clear skies!

John

For anyone in the Midlands, I have a seen the Aurora from the bogs outside Portarlington.
There is a lake about 2 miles north east of Port with a dark north Horizon.

Ill be heading that way myself at about 11.30 to midnight tonight.

For observers away from light pollution, no matter where you are, find an elevated site as much as possible, or a flat site with minimal horizonal obstructions.

Around Tullamore and within around a 15-20 minute drive, you have Finnamore Lakes and Boora on the Cloghan road, the bog between Ballinagar and Daingean, and along the esker at Durrow half way between Tullamore and Kilbeggan. I have seen aurora that was quite low in the sky from these locations in the past.

Photography Tip: Using either a 35mm film SLR or DSLR, choose an exposure of no more than 30 seconds, widefield, large aperture and no higher than ISO 800, no filters. From experience using both kinds of film and chip, after 30 seconds the stars will trail, and even longer shots will develop more ambient light pollution in the shot, which you don't want against the colour of the aurora. A higher ISO will bring more granulation. You can't really do multiple exposures of an aurora and stack them as the aurora itself moves and will therefore blur. If your aurora has spikes, you want those in your shot!

Seanie.

For small format DSLR's, which most of use have you want somewhere between 10 to 15mm of a lens, and @ f2.8 if you can. At that focal length you can get 20 to 30 seconds before trailing.
Anymore than that and as Seanie says you wont get the effect.

Shoot in Raw if at all possible, this gives much better scope for post processing and captures more detail.

White balance is also less important in RAW, but its best to get this right on the camera. The recommended setting is Daylight or 5200.

You need a good sturdy tripod and a remote or cable release for this kind of shooting. You cant capture this handheld.

ISO settings are very much depend on your camera. Most modern cameras (4 years old or less ) can handle noise up to 1600 ISO easy at night. For older Camera 800 is the max.
If you have in camera noise reduction this can be a great tool for the job, it will take a dark frame and subtract it from the image. Similar to what we all do in ccd and dslr astrophotography.
Again the new cameras will have this, the older, you would have to do this in Photoshop.

Another handy feature is Mirror Flip, which holds the mirror closed for a second allowing the camera to stop shaking before taking the shot. Again modern cameras, have a look in the settings.

My own settings will be, a 10mm lens at f4 (that's its limit) 20 seconds at ISO1600, with In camera Noise reduction on and mirror flip.
This effectively means that I will have to press the shutter release 3 times to take the picture

Best of luck everyone

Well, did anyone see the lights last night? Please feel free to report

Sean

Nothing but cloud and fog in south Dublin.