The astronomical object known as Crab Nebula is thhe remnant of an exploded star. The explosion was seen by the Chinese in 1054 C.E. However, the Crab Nebula is about 3500 LY distance from the Earth In what year did the star actually explode.

Question

jamesj · Answer

If something is 3500 light years away, how long did it take the light to reach us?

jamesj · Answer

talk to me, or I'll go away

anonymous · Answer

yes what year were we able to notice the explosion here on earth

jamesj · Answer

No. The year in which we saw the explosion was 1054 CE or 1054 AD, whichever you prefer.

If something is 3,500 light years away, it takes the light 3,500 years to reach us. 

Hence in what year did the explosion occur?

anonymous · Answer

1054 C.E.

anonymous · Answer

and yes that is correct

anonymous · Answer

what earth year did the explosion occur

jamesj · Answer

No.  The star exploded 3500 years BEFORE the light reached us. The light from the explosion took 3,500 years to reach us.

jamesj · Answer

We observed the explosion in 1054 CE. But how long before then did the explosion occur?

anonymous · Answer

yes

jamesj · Answer

We OBSERVED the explosion in 1054 CE. But in what earth year did the explosion actually happen? The answer is NOT 1054 CE.

We saw the explosion from light that travelled for 3,500 years before reaching us.

Hence the explosion happened 3,500 years before we observed it.

Hence the explosion happened in which year?

anonymous · Answer

I'm supposed to find out what Earth Year the explosion occured if the explosion was observed in 1054 C.E. and Crab Nebula is 3500 Light Years Distance from Earh

jamesj · Answer

Yes, that's what I'm helping you find out.

The crab nebula is indeed 3500 light years away. That means the light took 3,500 years to reach us.

anonymous · Answer

correct

anonymous · Answer

3500 LIGHT YEARS

jamesj · Answer

Yes ... hence if the explosion occurred 3,500 years before 1054 CE, in what year did it occur?

jamesj · Answer

Let me illustrate with another example.

The closest star to earth is 4 light years away. Suppose we saw it blow up tonight, on this day in February 2013.

When did it actually blow up, in terms of the earth's calendar? Well, since the light took 4 years to reach us, it actually blew up in February 2009.

Now ... using that example, when did the supernova that formed the Crab Nebula explode?

anonymous · Answer

so 3500-1054

jamesj · Answer

3500 years before 1054, hence
1054 - 3500 = -2446

which we call 2446 BC or 2446 BCE