Comet ISON is Still Dead

The definitive results are in from the Hubble Space Telescope… Comet ISON is still dead.

ISON SOHO LASCO C3
What remains of comet C/2012S1 ISON after perihelion in the SOHO LASCO C3 imagery
On the 18th the Hubble team imaged the expected coordinates of comet C/2012 S1 ISON and found nothing. Given the sensitivities of the instrument and the exposure length, anything brighter than 25th magnitude would have been detected. There was some uncertainty in the position, thus several different locations were imaged with Hubble.

25th magnitude is a lot deeper than amateur attempts at recovery, though the amateur efforts likely covered a great deal more area than Hubble with wider fields of view. Still, there have been no reports of any remains detected by any searcher.

Does this rule out any surviving fragments?

We can’t completely rule out the possibility that something is left of the comet. After all, it was seen after its passage close to the Sun, but disappeared not long after. This material would still exist, but is likely very diffuse gas, dust, and very small pieces spread over an extremely large area. – Zolt Levay, The HubbleSite Blog

I think it is pretty safe to call this comet dead.

Postcard from the Universe – Christmas Tree Cluster

A seasonally appropriate astrophoto, NGC2264, also known as the Christmas Tree Cluster. It does have the outline of a tree decorated with stars in place of ornaments. This was shot on the evening of the 23rd from the driveway.

Keeping the exposures short I concentrated on the stars rather than the nebula that fills the region. I am working on the appearance of my stars, attempting to improve my technique. Not sure if I have succeeded here, they are better. I used some Photoshop tricks to preserve the color of the stars in working on the image. Better, but not quite up the the standard I aspire to.

There seem to be a few deep sky objects that are appropriate for the season. The Rosette Nebula makes a nice wreath, the Christmas Tree, etc. The folks at WISE published a nice infrared image of Barnard 3 that also looks like a wreath. Long winter nights are an excellent time to consider the night sky. Not much else to do, I am on call for the weekend, thus staying home. It is new moon and the recent storms have departed allowing dark skies. May as well take a few more astrophotos.

Mele Kalikimaka!

Christmas Tree Cluster
NGC2264, the Christmas Tree Cluster, a stack of 27 x 1min exposures with the AT6RC and the Canon 20Da

The Rise and Fall of Galactic Cities

JPL Press Release…

In the fable of the town and country mice, the country mouse visits his city-dwelling cousin to discover a world of opulence. In the early cosmos, billions of years ago, galaxies resided in the equivalent of urban or country environments. Those that dwelled in crowded areas called clusters also experienced a kind of opulence, with lots of cold gas, or fuel, for making stars.

Today, however, these galactic metropolises are ghost towns, populated by galaxies that can no longer form stars. How did they get this way and when did the fall of galactic cities occur?

A new study from NASA’s Spitzer Space Telescope finds evidence that these urban galaxies, or those that grew up in clusters, dramatically ceased their star-making ways about 9 billion years ago (our universe is 13.8 billion years old). These galactic metropolises either consumed or lost their fuel. Galaxies in the countryside, by contrast, are still actively forming stars.

“We know the cluster galaxies we see around us today are basically dead, but how did they get that way?” wondered Mark Brodwin of the University of Missouri-Kansas City, lead author of this paper, published in the Astrophysical Journal. “In this study, we addressed this question by observing the last major growth spurt of galaxy clusters, which happened billions of years ago.”

Continue reading “The Rise and Fall of Galactic Cities”

Postcard from the Reef – Scorpion

I have found these fish in the daytime, usually deep inside a cauliflower coral and nearly impossible to photograph. By night they emerge to hunt. As with most scorpionfish, they are ambush hunters, sitting on the bottom and waiting for some hapless critter to come too close. Of course the habit of sitting still makes them ideal targets for a camera, they hold their ground even when the strobe goes off.

Cheekspot Scorpionfish
A cheekspot scorpionfish (Scorpaenodes littoralis) near the shore in 4′ of water, Mahukona

Casino Night Photography

Last night was the company Christmas party. We did something different this year, a casino night. A full set of dealers and tables awaited us at the Mauna Lani clubhouse for the evening. Signing in at the door everyone received a stack of play money and the fun began.

It was fun in two ways… Playing the games! Everyone seemed to have a great time, particularly with no real money at stake. I noted that we were all quite conservative at the start, as the evening progressed the bets became risky and the money began to really fly about.

It was also fun because I thought to bring the new camera. I know of no real casino that would let me take pictures of the games like this. Alas, this was not real. There was the added advantage that everyone knows me and knows how I use the camera. I did get good photos of more than a few people. Photos I will have to process up and distribute over the next few days.

A full frame camera with a fast lens was just what was needed for the evening. I only brought the one lens… A 50mm f/1.8 prime, the nifty fifty. It turned out to be the perfect lens for the evening. The lighting was dim, to be expected, but it was also very hard. Small quartz spots illuminated most of the gaming tables resulting in bright areas and dark backgrounds.

To the hard lighting I added the very shallow depth-of-field that comes with a fast lens and large sensor camera. The result was perfect, very moody shots of the game with fantastic bokeh…

Fatal or Not

I had never before seen one on the reef, but I knew what it was immediately…

This thing could kill me!

It is odd to look at something so small and pretty and realize that it could be fatal to touch. There are three cone snails that feature a potentially lethal venom found on Hawaiian reefs, the textile cone (Conus textile), the banded marble cone (Conus bandanus), and the striated cone (Conus striatus oahuensis). All three feature similar markings, a sort of chevron pattern on the shell. I did not recall which one of the three I was looking at, but I knew it was one of them.

Then I see the legs.

Small red and yellow legs protrude from the shell, just barely visible underneath. No problem, the deadly snail is gone and something else has moved into the pretty shell. A hermit crab, appropriately enough a cone shell hermit crab.

With little to fear from a hermit crab I set the shell just so on the coral. I know that the crab will wait a few moments then emerge to right his shell, providing a perfect photo opportunity…

Cone Shell Hermit Crab
Cone shell hermit crab (Ciliopagurus strigatus) occupying the shell of a textile cone snail (Conus textile)