supernova – Page 2 – A Darker View

Driveway Astrophotography and Comet Garradd

Finally, a night where… A) The sky is clear. B) The wind is not howling through the palm trees. C) I am not exhausted by working the summit. D) I do not have to get up early the next morning.

A + B + C + D = Astrophotography from the driveway!

Comet C/2009 P1 Garradd on 29 March 2012 showing both tails, sum of 50 x 1 min exposures CoolSNAP ES and 180mm f/2.8 lens

Thus, under a very pretty sky, I rolled the photo rig out of the garage and spent some time getting everything back together. I was not in a hurry, time to let a bright crescent Moon set a little and my primary target rise a little. The target at the top of the list? Comet C/2009 P1 Garradd.

The comet is nicely placed in Ursa Major, transiting late in the evening, available for several hours of exposures. And expose I did, with the auto-guider locked on the a dim star beside the comet, the shutter open for well over two hours. I was shooting my Canon 20Da and the AT6RC, a combination that framed the comet nicely.

It will take a while to get the resulting images processed. In the meantime I did a quick process on a set of images taken with the wide field/finder CCD camera. The results of which can be seen at the right. I also shot a few quick images of the M95 area with the CCD to capture SN2012aw.

Keck and a Nobel Prize

We are celebrating a bit at Keck today. It is somewhat unusual for an astronomer to be awarded the Nobel Prize in Physics. Today it was announced that three astronomers will share the award for their work in cosmology. Saul Perlmutter, Brian Schmidt, and Adam Riess led a pair of teams that were investigating the expansion of the universe through observing type Ia supernovae. Saul Perlmutter led the Supernova Cosmology Project, while Brian Schmidt and Adam Riess led a separate group, the High-Z Supernova Search, performing nearly identical work.

Both teams discovered something disturbing in the data. The expansion of our universe appeared not to be slowing as astronomers expected, but actually accelerating. The result, had both teams scrambling to understand the data, checking and triple checking everything in an attempt to see where they had gone wrong in their analysis. When each team finally published they were glad to see that they were not alone, that another group had independently confirmed this unexpected discovery.

A couple decades later we have come to accept this result as further data has accumulated. We now understand that there is another element of the universe that had not been appreciated before. What the astronomers had found was the effects of something that had been hinted at in a number of physicists theories (including Einstein), something we now call Dark Energy.

SN2011fe in M101 — Type Ia supernova, SN2011fe, in the galaxy M101

The teams used a number of different telescopes in a coordinated effort to both discover and then obtian the spectral data on the supernovae. Smaller telescopes would be used to discover the supernovae, searching wide swaths of sky looking for these rare events. Then the team would use large telescopes, like Keck, to gather the spectral data of the supernovae. The spectra would confirm the event as a type Ia supernova and give the redshift.

The most critical data, the spectra of the furthest and faintest supernovae, were made possible by the Keck telescopes, then the largest in the world. It is these most distant objects where the effect of our universe’s accelerated expansion is most noticeable. Looking through the tables of data in the original scientific papers, the Keck Observatory is often credited.

It is somewhat unfortunate that only a few individuals are named with a Nobel Prize. The discovery of dark energy and the acceleration of the expansion was an effort made by teams of individuals. Both supernovae search teams and all the members deserve real recognition for this. In turn their efforts depended on the staffs of the observatories that made the observations possible. Big discoveries are rarely made by individual scientists, but by the cooperative effort of many. There are only three names on the Nobel Prize, but a lot of folks are celebrating today.

Nobel Prize in Physics Awarded for Accelerating Expansion of the Universe

W.M. Keck Press Release…

The expansion of the universe is accelerating, and this is likely driven by dark energy, a mysterious repulsive force. Three astronomers won the Nobel prize on Tuesday for their research on exploding stars, or supernovae, that led to this profound cosmological conclusion. They are Saul Perlmutter of the Lawrence Berkeley National Laboratory in Berkeley, California, Brian P. Schmidt of the Australian National University in Weston Creek, Australia, and Adam G. Riess of the Space Telescope Science Institute and Johns Hopkins University in Baltimore, Maryland. Their discovery relied fundamentally on spectroscopy using the W. M. Keck Observatory and its LRIS spectrograph, in the period 1995 to 1997.

Perlmutter, Schmidt and Riess were members of two competing teams who were both studying the most distant supernovae. These Type Ia supernovae have been demonstrated to be “standard candles” and can thus yield relatively precise cosmological distances. The Keck spectra of the extremely distant supernova candidates were essential in order to indicate they are Type Ia, and to determine the redshift, or its velocity as seen from Earth, of the galaxy hosting the supernova. It was the redshifts and distances of a modest number of distant supernovae that revealed that the expansion of the universe was not slowing down, as was predicted, but in fact was inexplicably speeding up. The accelerating expansion of the Universe, first reported in 1998, was confirmed by the two separate groups. This accelerating cosmological expansion and the hypothesis that it is driven by dark energy has now become one of the most important areas of study in astronomy and physics today.

At the time, “We were a little scared,” Schmidt said. Subsequent cosmological measurements have confirmed that roughly 70 percent of the universe by mass or energy consists of this anti-gravitational force called dark energy.

In fact, Albert Einstein introduced this bizarre behavior with a fudge factor in his equations in 1917 to stabilize the universe against collapse. He later abandoned this idea, and then considered it his greatest blunder. “Every test we have made has come out perfectly in line with Einstein’s original cosmological constant in 1917,” Schmidt said.

In the years since then the three astronomers, along with their collaborators, have shared a number of awards, including the Shaw Prize in Astronomy, for this ground breaking research.

Perlmutter, who led the Supernova Cosmology Project out of Berkeley, will get half of the prize of 10 million Swedish kronor ($1.4 million). The other half will be shared between Dr. Schmidt, leader of the rival High-Z Supernova Search Team, and Riess, who was the lead author of the 1998 paper in The Astronomical Journal, in which the dark energy result was first published. They will receive their prizes in Stockholm on December 10.

“The recognition by the Nobel Committee of the importance of this work validates the enormous value to our society of ground-based optical / infrared astronomy,” said Taft Armandroff, Director of the W. M. Keck Observatory. “By making our two Keck telescopes and their instruments work at the highest performance, transformational science like that of Saul Perlmutter, Brian Schmidt and Adam Riess happens.”

The W. M. Keck Observatory operates two 10-meter optical/infrared telescopes on the summit of Mauna Kea on the Big Island of Hawaii. The twin telescopes feature a suite of advanced instruments including imagers, multi-object spectrographs, high-resolution spectrographs, integral-field spectroscopy and a world-leading laser guide star adaptive optics system. The Observatory is a private 501(c) 3 non-profit organization and a scientific partnership of the California Institute of Technology, the University of California and NASA.

Supernova 2011fe in M101

I have been watching the supernova nearly since it erupted around 23 Aug. We first viewed the supernova on 26 Aug using Cliff’s 24″ scope in the schoolyard of Waikoloa Elementary. I have since seen it about half a dozen times, as it brightened and peaked at around 10th magnitude in mid September. The supernova has since dimmed somewhat, now about 11.5 magnitude, but still quite easy to find with a small telescope. It is brighter than the host galaxy, M101.

Not a great picture. The galaxy was setting and I was shooting as it slid behind the shoulder of the mountain. All I could manage was a quick sequence of a dozen 30sec images. Still, you can actually see the galaxy and supernova. The image is much as it appears in a larger telescope around 14-20″ of aperture under a dark sky.