Final answer:
E.E. Barnard faced professional obstacles related to his intense dedication to his work as an astronomer, fears about his lack of formal education, concerns about being scorned by peers, and the anxiety of reverting to poverty. His extreme work ethic often conflicted with his personal well-being, leading to an inability to take vacations unless seriously ill.
Step-by-step explanation:
One professional obstacle that Bradbury faced, specifically discussed by Donald Osterbrock, was related to the noted astronomer E.E. Barnard. Barnard was described as an "observaholic", whose mood was greatly influenced by the clarity of the sky for his nightly observations. He experienced a deep-seated anxiety about his lack of formal training and was constantly fearful of being scorned by his peers or slipping back into poverty. This personal struggle with his professional stature and insecurity about his education could lead to significant stress and was a substantial obstacle he had to overcome in his career.
Barnard's ability to work was also described as obsessive; he found it difficult to take vacations and was so dedicated to his work that only serious illness could prevent him from observing. This extreme dedication indicates that professional obstacles for Barnard were often entwined with his personal challenges and mental health, making it difficult for him to find a balance between work and life.