The Last Interferometer Run

Tomorrow morning I will begin to power down the systems. One by one I will open the switches on gear that has rarely been powered off in years. In a matter of minutes it will be off. Dozens of computers, servo drives, camera controllers, racks of gear, silent and dark. I will also shut off the liquid nitrogen to each camera in turn. This will take a bit longer, a couple weeks will be needed to properly warm and back-fill each camera with dry nitrogen for storage. Meanwhile, Brett will carefully cover each optical surface in optical cloth and plastic. A few bits of gear installed in the telescope will be removed to be stored in the basement. By the end of August the Keck Interferometer will be mothballed.

This is the last run, three nights of observations. Two of those are behind us, the third beginning, the end is rapidly approaching.

FATCAT Dichroics
The FATCAT dichroic beamsplitters in the Keck interferometer beam lab
I look about at all of the gear and consider the thousands upon thousands of hours it took to assemble, test and troubleshoot this complex scientific instrument. Years of work by so many people. I look about the control room at the racks of equipment, the masses of cabling, the physical results of so much effort. The non-physical likewise represents a staggering amount of work, the software that allows the entire system to operate. My own contribution seems insignificant. Here and there I note pieces of gear I installed, cables run, cards I have modified, and some many parts of the system that I have had to repair across the years. The sense of loss at shutting this system down is overwhelming.

The plan is to carefully mothball the interferometer in place, in such a way as it could be reactivated with a few weeks of work. Maybe, some source of funding might allow the instrument to be used again, that is the hope. But we know how difficult the current budget environment has become.

Fast Delay Lines
The Keck Interferometer beam expanders and fast delay lines
Still, we are going out in style. This last run has attempted what has never been tried before… We are using AO lasers on both telescopes to reach targets never reachable before. The newly commissioned Keck 1 laser capability making this possible. We have successfully gathered data using the dual laser AO mode, a real first.

Oddly, one of our laser spotters did not make it to the summit and I was obliged to fill in. Fortunately it was a lovely night on the summit, not very cold and with no wind to make it miserable. For a couple hours I relaxed in the Laser Suzan chair, watching the sky. Above me arched the Milky Way, somewhat dimmed by a bright Moon, but still beautiful. A few bright meteors punctuated the night. The scene was a made a bit surreal by three lasers, all targeting the galactic core, the very center of our galaxy. Beside me the camera regularly issued the soft sound of the shutter, taking images of the night.

The second night was a series of galactic targets and a couple AGN’s. The final analysis will take time, but initial indications are that we have good data on at least some of the targets. A couple targets proved too faint for the system to track on. No surprise, we planned to reach a little with this last run.

Thus we begin this last night, the practiced evening routine is complete, final checks done. The last targets a list of selected YSO’s (young stellar objects) to be observed in L-Band. We settle in for the night, hopefully a quiet night. As usual, if I am busy, things are not good. All is going well, a fitting end to the instrument and a testament to all those who have put so much into the system. Something to remember.

A New Family Member

Meet Electra, the newest addition to the Cooper household. Today we came back from the Kona Humane Society with a kitten. As per household tradition the name is that of a star, 17 Tauri, one of the brightest in the Pleiades star cluster.

Electra
A new kitten in the house, introducing Electra
You may notice the photo is slightly blurred, much like an electron this kitten never stops moving. Getting a decent photo is proving challenging. I am going to have to break out a faster camera than my little G11. Perhaps a DSLR in high speed burst mode can do the job, then again, maybe not.

It has been three months since we buried Adhara, three months with an empty, cat-less house. There has been something missing around this place. No fur-face looking to curl up with you when you get comfortable. No begging eyes at your feet when breaking up a roast chicken.

Meanwhile this little flash of fur has been streaking all over the house. Finding the interesting places. In and out and under everything. There are things we humans need to put away, out of little paws reach. There are other places where kittens should not go, a couple of those have been found already. But then, some things are learned only through impact.

High speed, wood floor, and screen door… Thud.

Yeah, saw that one coming.

Eventually she might slow down. Maybe? Perhaps? Before midnight?

After years of living with two elderly and mostly sedentary cats, a kitten is a real change. It will take time for us to come to know one another, eventually we will learn the routine. No regrets, I am truly looking forward to having a cat around again.

Did I say cat? Make that cats, there will be two. A second little fellow has been selected, but he is not yet ready to come home, a little surgery awaits before we can go collect him and complete the family. I will have to introduce him in a later post.

A Dummy Battery Adapter for the Canon 20Da

Another quick project to solve a little equipment issue. I realized I had a problem the morning before I was planning to spend a night shooting astrophotos up on the mountain. The batteries for my 20Da are old and do not hold a charge, no way I was going to be able to use the camera through the night.

The Regulator Installed
The regulator circuit installed inside the battery shell and connected to the existing contacts
The camera is an older model that remains quite valuable to me as it has been adapted to shoot astrophotos. The 20Da model differed from the standard 20D in having live focus and a re-tuned red cutoff filter that allows the glowing red of nebulae to reach the sensor. After seven years I still use the camera regularly.

I have the AC power supply for the 20Da, this is what I have been using for some time now. Shooting astrophotos in the driveway allows access to AC power. For field use this will not do, I need to operate fully from battery power. The camera batteries that I do have for the camera are now at least six years old, and do not hold enough charge to last.

Without AC power available I needed something that could plug into one of my 12V field battery packs. I really did not want to cut up the existing AC power supply to create a version to be used with an external battery. Plus, Canon used odd, proprietary connectors on the supply. (I really hate it when they do that!) I can not even use parts of the AC supply without modification.

With only a few hours available I came up with a plan. A little digging showed I had all of the needed components on-hand. Off to the work bench!

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The Moon, Mars, Saturn and Spica

A nice conjunction of a crescent Moon, Mars, Saturn and the bright star Spica will grace the evening sky tonight. All four will be within 12° of each other. The two planets and the star will all be about 1st magnitude, with the Moon showing about 37% illuminated.

The same quartet will get together again next month, for an even tighter grouping.