Robotic Telescope Captures Clear Images of Exoplanet Stars, Theresa Chong, 2014
The following article was posted on IEEE Spectrum’s website on August 11, 2014. Corrections to the article were published on August 12 and can be seen in the article below.
1. From earth, a robotic telescope, called Robo-AO, can now snap high
2. resolution images of stars near exoplanets and automatically set itself
3. up to research hundreds of new targets each night. Although adaptive
4. optics is an established technique, an international team of researchers
5. says that Robo-OA is the world’s first fully autonomous laser adaptive
6. optics and imaging system. The benefit: Robo-AO, which is attached to
7. a 1.5-meter telescope, can study thousands of exoplanet systems in
8. record setting time.
9. The utility of most ground-based telescopes is limited because of the
10. blurring effects caused by turbulence in the earth’s atmosphere. But,
11. Robo-AO accounts for this turbulence, allowing it to capture images
12. rivaling the resolution of those captured by the Hubble Space Telescope.
13. Researchers designed the system, at a cost of roughly $1 million, so
14. that it can be applied to any 1-meter-to-3-meter-class telescope. Details
15. about the design and operation of the instrument were recently published
16. in the Astrophysical Journal.
17. “Ultimately we see that this is the kind of system that can end up on every
18. telescope of this size around the planet,” says Nicholas Law, assistant
19. professor at the University of North Carolina. According to Law, there are
20. a few hundred of these 1-to-3-meter-class telescopes scattered across the
22. Although laser adaptive optics systems have been around for the past
23. 15 years, their ability to lock onto a target is still relatively slow. It still takes
24. about 10 minutes to lock on to each new target, which might not sound that
25. long, but if you’re studying thousands of targets, it adds up. Robo-AO is the
26. first instrument to fully automate this tedious process, cutting the time down
27. to about 1 minute.
28. “That’s really new; no one has been able to do that before,” Law says. So,
29. instead of only targeting tens of exoplanet systems per night, now, telescopes
30. can target hundreds of them.
31. Speedy targeting times are one thing, but to capture clear images,
32. researchershad to remove image blurring due to turbulence in the earth’s
33. atmosphere. This two-step process started with researchers firing a laser
34. into the atmosphere to measure how the earth’s turbulence affects the
35. images captured. Then, they took the starlight that entered the telescope
36. and bounced it off a tiny micro-electromechanical deformable mirror. Using
37. the previous laser measurements as a benchmark, they deformed the
38. surface of the mirror so that it cancelled out the effects of the turbulence.
39. “In doing so, we end up with starlight as if it hasn’t gone through any
40. turbulence at all,” Law says.
41. This collaborative effort between researchers at the University of North
42. Carolina, the University of Hawaii at Manoa’s Institue for Astronomy, and
43. Caltech started around five years ago. Law says that the biggest design
44. challenge was developing “reliable and robust software so that the robot
45. would keep operating and control the many feedback loops.”
46. Now that all the software kinks are smoothed out, Robo-AO is undertaking a
47. huge variety of science research, including surveying 4,000 potential
48. exoplanet systems discovered by Kepler to validate if their are indeed
49. planets there or not. It’s also occasionally studying asteroids, comets,
50. moons, and planets in our solar system. According to Law, they have
51. already observed more than 12,000 stars, and they’re currently
52. searching for funding to set up a second Robo-AO system.
According to researchers, what was the challenge when building the Robo-AO?