** Update 10:30 p.m. CDT: After a day with lots of auroral activity in the eastern hemisphere, we’ve been in a lull the past few hours now that darkness has come to North America. No aurora to report yet, but it’s only just getting dark here. I’ll update again in a bit.
** Update 1:15 a.m. CDT: We’ve had a low arc and a couple faint rays show in the past hour. Still pretty quiet. Got this sneaking feeling it’s going to erupt 10 minutes after I fall asleep.
Based on the current forecast, the aurora should become visible right at nightfall across the northern sky. If your forecast is for clear weather, and you don’t already have an observing site picked out away from city light pollution with an open view to the north, take some time to find one today. I usually find observing spots by driving around the countryside looking for a quiet gravel road with a view to the north.
No equipment is needed to view the aurora, but many of us like to take a camera and tripod along. If that describes you, you’ll need a camera able to take time exposures up to at least 15 seconds. Because the aurora’s big, a wide angle lens is best. Set the lens to manual focus and your camera to manual (the “M” on the dial). Attach it to a tripod, then use the camera’s “live view” function to focus on a bright star. Don’t have live view? Try focusing on a cloud today and leave the focus there till you need it tonight — don’t touch!
Auroras vary a lot in brightness. For the faint ones, I open the lens all the way to f/2.8 to let in the maximum amount of light, then dial in ISO 1600 and take 30-second time exposures. With bright ones, keep the lens wide open and the ISO set to 1600 and shorten the exposure time to 10-15 seconds. If your pictures look too grainy at 1600, drop to ISO 800 and expose for 15-30 seconds.
Forecasts can change, so try not to be disappointed if the aurora shuts down early, but at least where I’m sitting on a Sunday morning, the picture for tonight looks rosy. Or should I say green?