Question

How can we see supernova remnant G1.9+0.3? If it is estimated to be about 25,000 light years away and now NASA says that it is about 140years old. How can we observe it? Wouldn’t it still appear as a star to us for the next 24,860 years or so?

Answer 1

Hint: The question clearly gives all the important points related to the supernova remnant. Recall when this event of supernova happened and whether the light reached earth during this event. Also, try to understand whether NASA’s claim on this supernova’s age means it really is of that age.

Complete step-by-step answer:
In the question we are asked about supernova remnant G1.9+0.3. It is estimated that this remnant is located about 25000 light years away and NASA claims that it is 140years old. We are supposed to explain how we can observe this supernova remnant.
Though the distance between the earth and the location of this supernova remnant is so huge as 25000light years, the light did reach the Earth surface when it went supernova some around 1868. By claiming that the supernova is 140years old what NASA intends to say is that we have been observing this supernova for about 140years and all these light had been travelling 25000years so as to reach the earth.

Note: The youngest known supernova remnant in the milky way G1.9+0.3 is found in the constellation of Sagittarius. It is a known fact that the explosion wasn’t seen from Earth because of being obscured by the dense gas and dust of the galactic center. The combined data from NASA’s Chandra observatory and the VLA radio observatory helped in establishing its young age.