Astrophoto Interference on Mauna Kea

Mauna Kea is simply a great place to shoot astrophotos from. Dark, clear skies with typically good seeing. Unlike some mainland locations there is a distinct lack of aircraft overhead. I am not sure how many shots I have had ruined by the bright anti-collision strobes crossing through the frame when shooting from locations in Arizona.

There are hazards to shooting photos here that do not commonly exist elsewhere. I was unpleasantly surprised when reviewing the take the next morning to find brilliant yellow lines through a hour and a half of exposures taken of the Cygnus region. The material is otherwise great, the makings of a nice shot, except for this one little issue. There are ways of suppressing artifacts like this when processing, but the beam is so bright I am not certain they will work all that well.

Worse, I checked the schedule, the offending laser is coming from Keck 2 AO, a system I work on.

The observatories have a system in place to deal with this issue. There are four operational lasers on the mountain, Keck 1 and Keck 2, Subaru and Gemini. Each optical observatory using a laser maintains a server that posts their laser location, status, and calculates the position of each beam in the sky. This can be queried by the other observatories to check if the beam crosses the field of view. A set of rules has been negotiated to determine who has right of way, usually who is on target first.

Obviously this computer system does not take into account my little telescope shooting photos from Hale Pohaku. If I had known I could have called Heather and asked her to shutter her laser, I was on target first. Being the kind soul she is, she would probably laugh with me.

Cygnus and Laser
Rough processing of a single frame, Cygnus region, with the Keck 2 Adaptive Optics laser crossing through the frame

The Transit of Venus

We did the Transit of Venus right.

The plan was to stream the transit live from the summit. With access to the Keck facilities we had internet, a comfortable break room, and an excellent vantage point from which to view the entire transit. It sounded so easy at first, just put a camera on a telescope and connect it to the computer for the duration. Easy, in concept. The reality? Not so much.

Venus Transit Second Contact
Transit of Venus 2012, second contact at 12:27pm

It was an incredible amount of work. I had spent several days during the preceding weeks preparing the gear for transit. I admit some of that was fun, an excuse to get the gear out in the day and look at the Sun, even photograph Venus quite near the Sun.

The webcast team consisted of three people, Larry O’Hanlon, the Keck PIO, Mark Senft, a volunteer from our astronomy club, and myself. Larry and I met a HQ to begin our drive up the mountain at 8am.

At Hale Pohaku we picked up Mark and enjoyed breakfast. Here we found a massive buildup in progress, a gathering of troops… Visitor center staff, Hawai’i County police and fire, and the Mauna Kea Rangers, all present in force. Stephanie Nagata, the director of the Office of Mauna Kea Management helped man the roadblock. Stewart Hunter, the head of Mauna Kea Support Services with her in an orange vest. Their preparations looked to be necessary, three hours prior to first contact the crowds of transit tourists were already growing.

Continue reading “The Transit of Venus”

JCMT and UKIRT Closing

Sad news that two of the telescopes atop Mauna Kea will be losing funding. Word comes from Tom on his blog Pacific View

• extend operation of JCMT to end September 2014, to allow for completion of the agreed science programme for the SCUBA-2 instrument on the JCMT

• cease STFC support for the operation of UKIRT from end September 2013, a year after the completion of its current survey programme

These shutdowns have been threatened for some time. It is disheartening to learn that the worst outcome is now reality.

Sunset Behind UKIRT
UKIRT opening for a night of observing atop Mauna Kea

A Dark Night

Another new Moon weekend, another observing outing to Mauna Kea. With some shiny new astro equipment to play with I decided to load for photography instead of visual. Disassembling the photographic mount I realized it had not been taken apart in over two years, setup in the garage and used in the driveway. I did not expect to be alone, a few other local observers had indicated plans to get out this night.

Omega Centauri
Omega Centauri, NGC5139, sum of 31 x 1min exposures, AT6RC and Canon 60D
Worry on the drive up, the cloud deck seemed quite high. I was concerned that the Mauna Kea VIS, at 9,200ft, may be in the clouds. With wipers and headlights on, through the heavy fog I drove, not encouraging when you expect to use a telescope. The worry persisted until the last switchback, ascending through the last wisps of cloud just a few hundred feet below the VIS to behold a cloudless blue sky overhead.

As expected the Mauna Kea Visitor Information Station was a zoo. A dozen summit tour buses added to a heavy Saturday night crowd. The parking lot was full with even more cars parked along the road. Not a real problem, the tour buses use reserved spaces right in front of the building. They pull out about an hour before sunset, headed for the summit with their customers. We swoop in on the vacated parking spaces and set up our gear.

Astrophotography
A trio of telescopes set up for astrophtography at the Mauna Kea VIS
The crowd is an interesting experience. Well over a hundred folks waiting for dark and the evening program. There are the usual issues of headlights and camera flashes. It may not be all that dark for a while, but we gain a nice paved place to setup, and there is electrical power available. The crowd will slowly wane as the night progresses, mostly gone by 9pm, driven off by the cold. At 10pm the VIS closes and the remaining lights are turned off.

In addition to the VIS telescopes, there were quite a few local amateurs taking advantage of a moonless Saturday night. Cliff and Tony brought Cliff’s 24″ Dob, a two person job to move that ‘scope. Wayne brought photography gear. Mike was likewise set up for photography, planets instead of deep sky, using a Flea 3 and an ancient 10″ Celestron. Olivier brought his 19″ Pricilla, providing plenty of glass for visual astronomy while the cameras exposed for hours.

It was Malalo o Ka Po Lani, cultural night at the VIS, with a special lecture. This meant a large crowd, most of whom stayed to enjoy the perfect skies the mountain provided this night. They wandered around the telescopes asking lots of questions. While the photographic ‘scopes did not offer views through the eyepiece, there was still a lot of interest in the process. I chatted with many folks as I worked, fiddling with the complex equipment necessary to take photos of the sky.

It was quite the gathering of Losmandy G-11’s! Wayne brought two, Mike brought one to carry the old 10″ Celestron, I had mine setup for photography with the AT6RC. Add the three that the Mauna Kea VIS uses! A testament to these well-built mounts, some of which are two decades old.

The astrophoto gear was working nicely. There were a few issues to deal with at the beginning of the night, the usual new gear stuff. A few things I need to fix before next time… need to remount the guider so I can co-align it with the imaging ‘scope. I need to mount a real finder, and make it easier to hunt down the targets. But overall I was pleased, the new setup worked as I hoped it would.

SBIG ST-i Autoguider
The SBIG ST-i autoguider mounted to the top of the AT6RC telescope
I will write more about the SBIG ST-i later. The short version… Much easier to use than the ST-4, accurate, painless acquisition of guide stars, it just locked on and stayed there. The only real drawback is the inability to dispense with a computer. I recently re-built one of my older laptops for use as the astrophoto machine. But since the computer is going to be there, I may as well use it, time to integrate the DSLR with the computer and shoot tethered. I have the software, just that I had tried to keep it simple in the field.

Another pleasant surprise was the ease of focusing with the AT6RC with a Bahtinov mask. I have been wondering about the stock focuser on the new ‘scope, how well does it handle the heavy DSLR camera. One lesson is that it locks the focus quite well, I noticed no drift each time I checked focus. Indeed, at one point I pulled out the 60D, swapped the focal reducer and adapter onto the 20Da and checked focus again, it was still perfect.

While my camera took exposure after exposure, I took in the views that big glass can produce. Bouncing back and forth between Cliff 24″ and Olivier’s 19″. No surprise for a spring session, galaxies were in rich supply. We viewed a lot of the showpiece objects, from Ursa Major to Virgo and Corvus.

This night was the type of night we hope for when planning an observing outing… Not too cold, no strong wind, and no clouds. Just a dark sky to delight the imagination all night long.

Viewing the Transit of Venus on Mauna Kea

Everyone is gearing up for the Transit of Venus. Starting at just after noon on June 5th, Venus will cross the face of the Sun. This will be our last chance to see such an event in our lifetimes, as a result, many skywatchers are making an extra effort to see this transit. This includes a number of folks who are traveling to Hawai’i this June, just to be here for the transit.

Transit of Venus
The June 2004 Transit of Venus, image credit Jan Herold
The Office of Mauna Kea Management and and Mauna Kea Support Services are making an extraordinary effort for the transit. An interesting exercise, protecting the mountain, ensuring everyone is safe, and allowing reasonable access to the summit. This is a challenge under normal circumstances. Throw in the possibility of a much larger crowd and it could be a real problem. Thus, the following extra measures will be in place…

  • The summit access road will be closed to public vehicular traffic at the Visitor Information Station.
  • Access to the summit will be provided via free shuttle service between the Visitor Information Station (VIS) and Mauna Kea summit.
  • Parking at the Visitor Information Station (VIS) is limited. Additional parking will be provided, however If parking spaces fill up, vehicles will be held below the VIS until parking becomes available.
  • Mauna Kea Rangers and Hawaii County Police Officers will be present to assist with parking and public safety.

There will be solar telescopes stationed at the MKVIS, at the summit, and at a number of other locations around the island. With many options to choose from, you do not need to go to the summit to get at least some view of this event.

The diehards, those wanting to see the entire transit, will probably go to Mauna Kea. I really do not know what sort of crowd to expect on the mountain. While it could be substantial, I really expect a more modest showing than some folks are predicting. In any case it will be a fun event.

Myself? I will be on the summit. I will be running the Keck live webcast of the event using one of my telescopes. From a vantage point behind the Keck 1 telescope we should be in position to witness the entire event from start to finish.

Postcard from the Universe – Telescopes

Two telescopes set up on the side of Mauna Kea. Olivier’s 12″ and my 18″ Deep Violet. A full night of deep sky observing under very nice conditions.

The photo was taken with a red LED light swept over the area during the 20 seconds of exposure. The camera had other ideas, set for automatic white balance it attempted to correct the color, fairly successfully. Surprising given the monochromatic nature of the light source.

As usual, click on the image for a larger version…

Mauna Kea Observing
Two telescopes set up under dark Mauna Kea skies