[Solved] As an astronomer, you observe the night sky on a regular basis. One night, you notice a new, bright star visible with the naked eye. Within the next two years, the new star vanishes from sight. Which of the following best describes the object you observed? A) a super bright planetary nebula B) a white dwarf explosion C) a supernova explosion D) a red giant explosion Post-traumatic Stress Disorder: A disorder related to mental health, sparked by involvement in or witnessing of an event causing extreme fear, defined by involuntary recollection, terrifying nightmares, and deep anxiety. Schizophrenia: A severe mental disorder characterized by distortions in thinking, perception, emotions, language, sense of self, and behavior. Positive Symptoms: Those symptoms of schizophrenia that indicate the presence of inappropriate behavior, such as hallucinations, delusions, agitation, and inappropriate giggling. Negative Symptoms: Those symptoms of schizophrenia that reflect the absence of appropriate behavior, such as blank faces, monotonic voices, and motionless bodies.