What is special about the star V838 of the Monoceros constellation depicted in the picture?

If it is 19,000 light years away wouldn't it have exploded 19,019 years ago?

Mark V, true, however, covering distance does require a time element

Miss Lisa, that is how light years work. Light years are a measure of distance - the distance equal to something traveling at the speed of light for an earth year.

Dan, you are correct. The star did not explode in 2002. The question should be corrected to “was observed to explode in 2002” …

Mark V, a light-year is relative to the observer..it can be time, distance or both depending on what you are measuring.

Dan, it exploded millions of years ago. we're just seeing it now.

Dan, A light year is the measure of distance not time.

From the Comments, it seems that many of our contributors are extremely knowledgeable on the subject of astronomy, especially Nostromo- unless he was kidding us, of course!

Tom, hope they took into account the red shift as well as galactic rotation, plus any dark matter gravitational effects, if that even exists. ;)

Dan, you are right if a Newtonian description is used. However, using a universal time is not ok in either Special or General relativity. But at 20 000light years, the relative speed is not great and there is no mention of a great gravity event so your simplification is ok.

Dan. That means it would of exploded in about 81AD Too late for Jesus to see it happen even if he had the telescope to be able to see it. Then again god could of told him if Jesus had been alive at the time. Clearly they could not see the planet go into the star just an explosion. All very interesting though.