Category Archives: supernova

Stalking the Wild Supernova

Rule 1: Be Prepared

Rule 2: Use Lots of Observatories

Satellite images of galaxy NGC 2770The big news about Alicia Soderberg and Edo Berger’s observations of a supernova just beginning its explosion is one of those great stories that illustrates the saying “Chance favors the prepared mind.” A few months ago when both authors were writing an article about their find for GeminiFocus (a magazine on which I’m associate editor), I marveled at how lucky these two were. But, they were doing more than just being in the right place at the right time. They also had the capability to reach out and grab use of several observatories to get the best multi-wavelength view of the supernova (which blew up in the galaxy NGC 2770 (which lies some 88 million light-years away from us). Of course, SWIFT saw the first x-ray emissions from the supernova, and the astronomers noticed that right away. In short order, the pair alerted the astronomy community, and soon the orbiting Chandra X-ray Observatory, the Very Large Array radio telescope in New Mexico, the Gemini North and Keck 1 telescopes in Hawai’i, two telescopes at Palomar Observatory in California, and a telescope at Apache Point in New Mexico were all looking at this outburst.

The combination of observations from all this observatory “firepower” pins down the moments when the first x-rays began streaming from the star. Eventually this information will help astronomers understand the moment-by-moment events that occur when a massive star finally explodes as a supernova. It’s a look at stellar death throes that wouldn’t have been possible even a few years ago. Chance — and a lot of really good telescopes — really do favor the prepared astronomers who got this chance to look into the jaws of star death.

A Star Set in Stone

The supernova depiction at Chaco Canyon Copyright 2002, Mark and Carolyn Collins Petersen
The supernova depiction at Chaco Canyon © 2002, Mark and Carolyn Collins Petersen

A year ago we vacationed in Chaco Canyon in New Mexico for a couple of days. One of our goals was to hike out to the site of a pictograph drawn on a rock overhang that is said to depict the appearance of a supernova that occurred in 1054 A.D. The artist was part of the Anasazi group of people who populated this canyon during that time, and much archaeoastronomical debate centers on just what it meant for the artist to paint the scene.

It must have been an eerie sight when the explosion flared into view over the eastern horizon early on July 4, 1054 A.D. Perhaps it had some ritual meaning to the Anasazi. Or maybe it was just their way of recording a strange thing in the sky. We’ll never know, but that doesn’t stop learned astronomers and ethnographic types from tussling over what the rock record means. One thing’s for sure, the presence of a bright “guest” star must have been a surprise to ancient stargazers who knew the skies quite well. Certainly the Chinese and Japanese thought it so remarkable that they recorded it in their writings, and there’s even evidence that people living on Guam noticed this outburst and drew pictures of it on cave walls. But, apparently, few in Europe saw fit to record this apparition, although it would have been quite bright in their skies.

A Crab Nebula finder chart
A Crab Nebula finder chart (right-click to download a fullsize version)

Can we see the supernova today? Well, yes, sort of. It has faded quite a bit from the glory days of 1054 A.D. when it rivaled the full moon for brightness. To see it with any detail you need a medium-to-large backyard-type telescope and maybe even a filter or two. It’s definitely not a binocular object but if you want to just see where the Crab lies, look toward the horns of Taurus the Bull after they rise up out of the horizon clutter on these November nights. The southern horn of the Bull extends out to a star called Zeta Tauri. The Crab lies just above that star.

VLT view of the Crab Nebula
VLT view of the Crab Nebula

Of course, observatory scopes are really good at digging into the heart of the Crab and showing us the spectacular details of this explosion. Here are two of my favorites: the first is from the European Southern Observatory and the second is a combined Hubble Space Telescope and Chandra X-Ray Observatory image:

HST and Chandra view the heart of the Crab Nebula
HST and Chandra view the heart of the Crab Nebula

I often wonder what the ancient Chinese, Japanese, and Anasazi peoples would think if they only knew just what it was they were recording on their parchments and sandstone? For them, this sight was a mysterious one — another symbol of something in the sky that they didn’t understand. But they surely appreciated the beauty of the apparition — just as today we look at it and try to comprehend the stellar forces at play in the death of a supermassive star.