An Unexpected Guest

The year 1054 was quite a year!

Something exploded! Except of course, it didn't! Well not actually then anyway. Who saw it? the Chinese, the Koreans, The Arabians, and the Japanese to name but a few.

A new star suddenly and dramatically appeared in the night sky that hadn't been there before. Then gradually it faded. So, they recorded it as 'a guest star'. What a lovely welcoming name for an unexpected visitor.

In the night sky today is the remnant of an exploding star called a supernova. IAn amateur astronomer, John Bevis discovered it in 1731. This photo on the right taken by the Hubble Space Telescope, is how it appears to us now.

A team of astronomers have researched in meticulous detail the likelihood of what we see today being the remnant of the explosion or 'guest star' that was witnessed in 1054. There is an extremely close match in ages, position, velocities of the filaments of gas speeding away from and towards us with the time of the new star seen in 1054. The research paper is in the following link and the pdf can be downloaded for free for those of you who like to know the detail. https://arxiv.org/abs/0801.0893

When exactly did this star explode? Well, it takes the light from the remnant called the Crab Nebular also Messier 1 (M1) , around 6500 years to reach us, so take that number from 1054 and you get... 5446 BC. It makes for interesting reading to find out what was happening on Earth around then.

In the centre of this remnant is a pulsar, also known as a neutron star. This is about the size of whatever town you happen to live in (much smaller than a city) and yet contains as much actual matter as our own star the Sun. It is rotating on its axis about 30 times every single second and emitting vasts amount of radiation. You can read more about the Crab Nebula in this link, https://www.nasa.gov/multimedia/imagegallery/image_feature_1604.html

Something to ponder: what does it actually look like now, the image given above is what we see after about 6500 years of its light speeding across the Galaxy to the HST - our great camera in the sky, yet, we actually have no idea other than what can be mathematically modelled as to how it looks now.
Enjoy finding out more about this extraordinary nebula.

Image credit: https://www.nasa.gov/multimedia/imagegallery/image_feature_1604.html