Hawaii’s W. M. Keck Observatory has successfully deployed a $4 million laser system that provides a marked increase in the resolution and clarity of what are already the most scientifically productive telescopes on Earth. The new laser was projected on the sky for the first time on the evening of December 1, 2015 and will allow scientists from around the world to observe the heavens above Maunakea in unprecedented detail.
“The Next Generation Laser System is the third generation of lasers at Keck Observatory, which has been pioneering Laser Guide Star Adaptive Optics on big telescopes since 2001,” said Jason Chin, the project manager for the new laser at Keck Observatory.
The first Laser Guide Star Adaptive Optics system on a large telescope was commissioned on the Keck II telescope in 2004 and, among many other firsts, helped reveal the black hole at the center of the Milky Way – one the most significant astronomical discoveries. The second laser system was installed in 2011 on the Keck I telescope, propelling Keck Observatory’s lead as the premiere Adaptive Optics research facility in the world. To date more than 240 science results from these laser systems have been published in astronomical journals.
Another great video from my friend Dan Birchall. There are more opportunities to see multiple lasers on the galactic center in coming months. I hope to get up and do some more shooting of my own.
TBAD is our Transponder Based Aircraft Detector, used to avoid illuminating an aircraft with the AO laser. A specially designed receiver that uses an antenna at the front of each telescope to detect the TCAS anti-collision transponder that is carried by all commercial and most civil aircraft.
The odds of our painting an aircraft with the laser is astonishingly small. There is very little air traffic over the summit, those aircraft taking off and landing on the island have descended to well below 14,000ft before approaching. It is also a very large sky in which an aircraft is a very small target. Even if we managed, somehow, to paint the aircraft, the effects would be minor to unnoticed. Essentially the same as shining a bright light on the bottom of the plane. I have stood in the high power beam, strong sunlight feels much warmer.
Still, we are mandated to avoid the situation and to put in place measures to avoid such an occurrence. Before TBAD this involved hiring guys to sit outside and watch the skies for aircraft. I have done this, it can be pretty on a clear night with calm weather. It can be brutal on a cold and windy night. Even when taking precautions such as rotating two spotters every hour or two there is always the question of human fallibility under adverse conditions. Using an automated system like TBAD is far preferable.
I am truly jealous! My friend Dan Birchall got the photo I had hoped to get… All four Mauna Kea lasers in operation at the same moment. Better yet, all four lasers were on the same target, the center of our Milky Way galaxy. The result is a great photo of four yellew beams converging to the same spot in the sky.
I had attempted to get a four laser shot last year. The one night all four were scheduled I was ready, on the summit with the needed gear for a photographic session. Three of the four lasers were operating, but Gemini had suffered problems and never propagated their laser. I have managed a few very nice three laser images, including one from last summer with three of the four aimed at the galactic center.
The four beams come from our two Keck telescopes, plus one from Gemini and one from Subaru. the lasers are used to create reference beacons for the adaptive optics systems used on these large telescopes. I will, with a little possessive pride, point out that the Keck lasers are much more powerful than the others.
The scheduling of all four lasers at once is a rare occurrence. All four lasers on the same target? Even more luck was involved! It helps that Dan is a telescope operator and spends far more dark time on the summit than most of us. He took advantage of the situation correctly… Grabbing the camera and shooting.
Below is more footage from Dan, a little time lapse of the telescopes working…