It was 24 million years ago. The Arabian shelf had only just begun to touch the Asian mainland and swamps the world over were drying up into grasslands. Grasslands were giving way to forests. Temperatures globally were starting to rise and in a scant 18 million more years, the first bipedial hominids would start trundling around the place. Breaking stuff, no doubt.
Meanwhile, somewhere far away – 24 million light years away, more or less – something entirely ordinary was happening: a white dwarf, at the end of its life, suddenly burst forth into a brilliant explosion of carbon and oxygen traveling at 6% of the speed of light. The blast, 5 billion times as bright as our own sun, is known as an A1 supernova.
24 million years later, the light from that event is about to shine down on the Earth, albeit very faintly. Its like peering 24 million years into the past to watch one single event that only lasts for a blink of an eye in interstellar time. And it is played out right there in our night skies on Earth.
So if you’re in Rochester, where should you be looking to spy this event? I spoke with Steve Frentes, Director at the Strasenburgh Planetarium, about just this. The bottom line? Be sure you know where the Big Dipper is, bring a good telescope and get out of the city entirely. Even then, its going to be difficult to identify the new kid on the block.
Why this supernova is such a big deal
Supernovas such as the one that will soon be visible are not only not uncommon, they’re actually common enough to be classified. This supernova is part of a category of supernova called A1 supernovas. They’re special because they decay at such a consistent rate that they’re used to gauge distances between galaxies.
But it isn’t often that we get to watch a supernova from its very first stages. That we’re able to observe this one is a tribute to the robotic observations of places like the Mount Palomar Observatory’s Palomar Transient Factory that discovered this one. Transient Factory observatories scan the sky and map the locations of objects night after night, making note of deviations. Most variations are regular and conform to what we expect objects in space to do. When something anomalous is identified, it is reported and checked by a human operator. Thus our ability to detect such minor changes in our sky as a dim supernova at the very first stages of ignition is significantly enhanced.
And distant though this event is, the Pinwheel Galaxy is actually one of our very closest neighbors. This means that researchers can watch this supernova decay perhaps for over a month and in any event, much longer than would normally be the case for any other A1 supernova. Scientists will be able to watch nearly a complete cycle of a supernova. What new data and insight into the nature of supernovas might be gleaned from this one is what has the scientific and amateur astronomy communities buzzing with excitement.
So now that we know what the big deal is, how do we find it?
Sam the Supernova
Finding this supernova is not going to be easy for amateurs. There are a few strikes against us.
First of all, the location. The supernova called SN PTF11kly (not a very snappy name, lets call it “Sam”) is located in the Pinwheel Galaxy (M101) which despite being one of our closest neighbors is very hard to see. The galaxy is inside the Big Dipper constellation, between the last and second to last stars in the Dipper’s handle, forming a triangle. That means its in the company of some very bright stars, adding to the difficulty of spotting it. However, this website shows that you can sort of hop from Mizar, that second-to-last Dipper star, up to the Pinwheel.
The Dipper itself will be very close to the horizon when it becomes visible, so if you’re planning on checking out the supernova, you’ll want to get away from any ambient light that will obscure the view. Think Adirondacks, which are just lovely this time of year.
Our buddy Sam the Supernova is part of this very faint galaxy. Merely another dot contained within the very bright Big Dipper, and Sam himself will be quite dim as well. At its peak luminosity (brightness), it will be around magnitude 11, which being 100 times fainter than the eye can detect on its own, means you’re going to need a nice telescope.
I asked Steve Frentes what kind of magnification he would recommend and he pointed out, rather obviously it seemed later, that magnification while important is less important than the amount of light you can get into the shot. So, what matters is a big, big lens. The bigger the better. A really high-quality set of binoculars will certainly get you closer, but a larger reflecting or catadioptric telescope would be better.
So this supernova is definitely for the intrepid star gazer. But seeing this amazing show is not impossible for your amateur astronomer at all and for the rest of us, simply knowing its there is pretty awesome.
And if you can’t see Sam, check out the ISS
But you don’t have to wait for another amazing galactic smash-up to see cool stuff right there above you. Steve also told me about a great website for finding man-made satellites in the night sky, heavens-above.com. You can use this site to find out when satellites will be visible, the direction they can be seen at and the peak brightness of the satellite. You can even use it to spy the International Space Station. Which is handy since it now appears that the ISS will be unmanned for an unspecified amount of time. So, with everybody gone, this is your way of checking up on the Space Station and making sure that nobody’s wrecking the place. Make sure the garbage gets taken out, stuff like that.