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 140 years old, how can we even observe it? Wouldn't it still appear as a star to us for the next 24,860 years or so?

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 140 years old, how can we even observe it?  Wouldn't it still appear as a star to us for the next 24,860 years or so?

Emilia Acosta · Accepted Answer

The supernova has been visible for 140 years.

Approximately 25,000 light years separate us from the star, but when it went supernova, the light reached Earth in 1868. According to NASA, we have been observing the supernova for 140 years, but the star exploded some 25,000 years ago, and it took 25,000 years for all of the light to reach us.

Lincoln Adams · Answer

undefined Supernova remnant G1.9+0.3 is observed with telescopes that detect a variety of light wavelengths, including radio waves and X-rays. Despite being 25,000 light years away, the explosion that created it occurred approximately 140 years ago, and the explosion's light and radiation are still visible to us today because they spread out over time and space.