Catching A Supernova

I saw the second supernova in my life last night. This would be SN 2011fe, which was discovered on August 24 by an automated sky survey at the Palomar Observatory. It is in the galaxy M101 (the Pinwheel Galaxy), which about 21 million light years distant, Two things are unusual about it. First, I believe it is the nearest supernova to occur since SN 1987A (a mere 168,000 light years away, back in 1987). Second, thanks to the automated observing network, it is the youngest type IA supernova ever observed, caught within 12 hours of the explosion. The supernova is destined to be one of the most studied such events for this generation of astronomers

I first heard about the supernova last Friday or Saturday, planned to look for it on Saturday, but was foiled by the presence of haze and smoke from a brush fire 20 miles distant. I have only seen one supernova in a telescope before, back in 1998 — I think was SN 1998bu in the galaxy M96, which got to about magnitude 11.8 in brightness. We were living halfway up the mountain behind Santa Barbara, a place with much darker skies than where we are now — I have great trouble seeing 12th magnitude stars in my 7” telescope here. So I looked on Sunday, and had no luck, cursing the bright skies here.

So I looked again last night, it being important to look before the moon gets too bright in the evening sky in the next several days. First looking through the eyepiece I thought it would go well. It did. When I had hopped to the correct star field there was a suspicious object. Was it the supernova? Or perhaps it was the 11.7 magnitude comparison star on my star chart? Comparing the geometry of the stars with those on the star chart it looked more like the former, but it wasn’t until I found a pair of stars at the upper part of the field pointing at the supernova on the chart did I confirm it. The supernova was now not at all difficult to see with direct, rather than averted, vision. A look at this light curve shows what has happened: between Sunday and Thursday the supernova brightened from about magnitude 12 to around magnitude 10.7. Wow. No wonder it was now pretty easy to see. I’ll be following it over the next several weeks, though the moon will make this difficult for a couple weeks

And now to look for a comet! I just heard about Comet Garradd today: it sounds like it is pretty easy to find.