Dr. Kimberly Ennico Smith, SOFIA Project Scientist
SOFIA, the world’s only flying observatory, is in Christchurch, New Zealand for the next few weeks, to enable unique infrared observations from the Southern Hemisphere. From here, we can study our galaxy’s center and nearby galaxies, the Magellanic Clouds, which will feature prominently in our observations in the weeks to come.
I flew onboard SOFIA on the journey south from its home base at NASA’s Armstrong Flight Research Center, in southern California. We stopped in Honolulu, Hawaii, to refuel and change crews on the way to New Zealand.
During the flight, I got a chance to hang out in the cockpit and spend time with the flight engineer. He explained what all the dials and buttons do — some monitor the temperature of the engines and control the engine heaters, others monitor the airplane’s elevation.
The rest of my fellow passengers were a mixture of mechanics, software engineers, telescope operators, and avionics technicians. We got to chatting about all sorts of avionics systems and swapped stories. They know the world of aircraft inside and out and it was truly a pleasure to pick their brains over the two long flights down south.
We are ready to observe the solar system and beyond from the National Science Foundation’s Antarctic Program Facility at Christchurch Airport!
Many thanks to the telescope operators for helping us through these complicated observations. The instrument for tonight’s and tomorrow night’s flights is the Cornell University developed Faint Object infrared CAmera for the SOFIA Telescope (FORCAST), a dual-channel mid-infrared camera and spectrograph sensitive from 5 to 40 microns.. SOFIA flies above 99% of the water vapor in Earth’s atmosphere that blocks infrared radiation from reaching the ground. The super dry atmosphere over the southern ocean was exceptionally good for the duration of the flight, which enabled the team to get better results.
During the first science leg we observed V1309 Scorpii. At first this object was thought to be a “classical nova,” where a white dwarf star accretes material onto its surface from a companion star until the material ignites, causing a surface explosion. But it was later determined to be an explosion resulting from the merger of a binary star system, where the two stars spiral in toward one another until they finally collide. This is a very faint source that proved to be exceptionally challenging to get set up to observe. Once the observations were under way, however, the data looked to be acceptable. Luckily most of the effort was front-loaded, since soon after we began observing in earnest, the flight crew notified us that we could see the aurora outside. And it was just stunning, brighter and more active than anyone on the main deck had ever seen.
The following science leg included observations of Eta Carinae, a system of two stars that are five million times brighter than our Sun. Eta Carinae can only be seen from the Southern Hemisphere, and this observation was the focus of our guest investigator, Pat Morris, from the California Institute of Technology, who was on board to assist with data collection. These observations proved to be challenging. The goal was to observe the faint emission surrounding Eta Carinae that originated in an earlier period of mass loss. To see this emission, we had to very carefully position the observation field next to Eta Carinae itself, the brightest IR stellar source in the sky. Unfortunately, besides the difficult setup, there were some technical issues on this leg that resulted in some lost observing time. Nevertheless, the data obtained looked very good. We are well positioned to optimize our observations of Eta Carinae on upcoming flights.
The last object we observed this evening was Westerlund 1 – one of the most massive star clusters in the Milky Way Galaxy. These observations were straightforward and rewarded us with some beautiful images of the most densely populated field observed by the FORCAST team to date.