Observing Supernova SN2014j (The Cigar Lights Up)
Eleven to 12 million years ago a white dwarf star and its companion star weren’t playing well together in the Cigar Galaxy, aka Messier 82 (M82). The white dwarf had been systematically accreting hydrogen from its neighbor and not sharing it with anyone but itself. Selfishly amassing this new material eventually caused the white dwarf to grow close to a critical limit at which point the white dwarf began to collapse. Its carbon core heated to an enormous temperature, too high for my limited keyboard skills to type, and triggered a catastrophic thermonuclear carbon burning that literally blew the white dwarf to smithereens propelling shock waves at tens of thousands of miles per second slamming into interstellar material, shock heating, compressing and enriching it in heavy elements. Risks of X-rays, gamma rays and cosmic rays persisted for years to decades afterwards for any planets existing in the vicinity of 100 to a few hundred light years with mass extinctions of some life forms possibly resulting. Planets 1000 light years away were swarmed with gamma radiation as if 10,000 solar flares suddenly fired off; and any planets with Earthlike atmospheres 3000 light years away from the blast would have had detectable effects in their ozone layers.
I was witnessing all this only in my imagination as one of several scenarios that scientists theorize on the consequences of supernovae. What I saw through the various magnifications of my eyepieces the night of January 29, 2014 from 8:30PM to 11PM when I was observing SN2014j in M82 was totally different. I was at the ChesLen Preserve with Bill McKibben and Jack Goodwin of DAS, plus Igor of the Bucks-Mont Astronomical Society. It was apparent from first observation that M82 was not the M82 I had seen dozens of times previously. This time there was a star in M82 where one was not before….
When I drove out of my driveway at 6:40PM the temperature was 19°F. I was driving wearing warm gloves, wool knit cap, lots of warm clothes and the heat off. The dashboard vents were wide open and the windows slightly cranked down helping my 18” mirror come to ambient as I drove. That way, after the scope was set up, I could be observing without too much concern for thermals from the mirror interfering with my views. Thirty minutes later upon arrival at ChesLen, Orion’s Sword caught my eye and I gave a quick scan around the perimeter of the distant tree line and above the Lenfest Pavilion. The winter Milky Way was absent but I was encouraged to see clear skies and bright stars except for a line of clouds hovering over the southern horizon up to about 30°. The light dome in that area was more apparent than usual because the clouds were reflecting the light from Kennett Square. Those clouds lingered the entire time we were present making the view of Thor’s Helmet (NGC 2359), at 15,000 light years away, very dim even through my OIII filter. Without the OIII the nebula was nearly invisible even to a trained observing eye.
The Trapezium’s 5 stars (a to e) in M42, the Orion Nebula, about 1400 light years away, was easily resolvable but the 6th (f star) was in and out, so I knew it was going to be a difficult night for Jupiter. Jupiter did hold up well at 117x and fairly well at 133x with the NEB and SEB very distinct, combined with well-defined polar cloud bands for an overall pleasing view. Beyond 133x it became a gob. Stick to the galaxies and nebulae, I thought to myself. The Orion Nebula showed beautifully at 173x and even pushing to 226x served up quite detailed patterns of varying contrasts, swaths of nebulosity reaching out like outstretched wings across a black sky and a mild peppering of stars.
The Crab Nebula (M1), at 6000 light years distant, the remnant of a supernova whose explosion was witnessed by Chinese astronomers in 1054 (which at its time was naked eye visible for 22 months) was very wispy, more like a patch of pale grey. A nebula filter helped a little by darkening the background and brought out some structure but the central neutron star remained elusive. NGC 40, a planetary nebula about 3700 light years away, usually is an excellent showpiece with multiple shell borders in my 18” at much higher magnification than the 133x I was using. But tonight it showed only a faint outer shell. Even that detail was very difficult to make out under the night’s conditions.
Using my wide field 31mm eyepiece (73x), that gives just about a 1° true field of view, the galaxies in the Perseus Galaxy Cluster (Abell 426), 250 million light years away, showed several tiny irregular patches amidst many broadly spaced stars. Positioned at better than 80° altitude, near zenith and the darkest part of the sky, averted vision brought a bonus of very faint, pale, almost indiscernible galaxies as small as an arc minute or less as I scanned around the cluster’s 18’ area with my 11mm eyepiece at 200x. While sharing the views with Igor he queried, “Do you think someone out there is looking back at us, too?”
With the 31mm back in the focuser and the Double Cluster (6800 light years away) at a nice altitude I slewed the scope to NGC869/884 for one of my favorite pieces of eye candy. These 13 million year old clusters of stars always stun me no matter what scope I use, from my modest 80mm f/6.1 all the way up to my he-man 18” f/4.3. Slowly scan across the members of this group of stars and they appear to ride the heavens like a swarm of color coded fireflies. Blue, white, red…, like bespeckled jewels salting black velvet.
We made the trip because forecasts supported that night as the only foreseeably clear night for this dark window to observe M82 and its new supernova. My first view of it was around 8:30PM. The yellowish, maybe somewhat pinkish light of SN2014j had traveled 12 million light years. It passed through my cornea at the front of my eye refracting the light as my iris barely regulated, if at all, the size of my pupil and focused the image onto my retina. I chalked off the color to atmospherics. Later I learned that this slight coloration was due to interstellar dust along our line of sight and in M82. Igor’s photograph that accompanies this report is an excellent rendition of the nearly photographic view we had through my scope, the most notable differences being brighter and better saturated color with round stars in the photo vs pinpoint stars and fine grey highlights through the eyepiece.
The temperature was now 15°F but there was no wind, so the wintry air was very tolerable under my multiple layers of layers. Jack Goodwin kept putting on another coat, over a coat, over another coat until he finally said, "I think I'm wearing every coat I own." By 10PM M82 was higher in the sky and above much of the glow of the horizon light emanating from Coatesville to the north. Structure within M82’s central star formation region was more evident as was some edge detail. But the supernova itself was the star of the night.
As I drove out of ChesLen at midnight my dashboard read 12°F and I savored the vision of M82’s new look. Perhaps SN2014j’s massive explosion was witnessed eons ago by denizens of M82. Did they gape at its brilliance similar to how the Chinese witnessed the supernova of 1054 in our galaxy that gave birth to the Crab Nebula?
I will consider myself fortunate to see SN2014j again. Reportedly it has already peaked in brightness and the weather forecasts were increasingly dismal for planning another session soon. This transient event of a star that exploded 12 million years ago will not last. Gradually over the next few weeks or months it will fade from our telescopes. In M82 its remnants have already faded and have drifted into the general population of interstellar gas within the host galaxy, recycled as foundation material for new stars.
More supernovae will, no doubt, erupt at levels too faint except for the largest amateur telescopes while others will excite us as SN2014j has. Very recently other supernovae were reported in NGC 7331, M99 and NGC 3448 and within the next 50 years our Milky Way is predicted to have a supernova of its own. Maybe those enriched heavy elements that were likely flung out of SN2014j will have become the carbon and iron atoms in some alien life form and someone in M82 will notice the Milky Way’s next supernova, albeit 11 to 12 million years from now.
Fred De Lucia
Sources for some of the information in this article:
Supernovae and How to Observe Them by Martin Mobberley, Springer Press (2007)
Sky and Telescope January 31, 2014 eNewsletter
The Oxford Dictionary of Astronomy, Second Edition, edited by Ian Ridpath (2007)
How the Human Eye Works www.livescience .com
Photo credit: through courtesy of Igor Peshenko of the Bucks-Mont Astronomical Association