Astronomy
| Group contact | Roy Fairclough Mobile: 07887 710272 |
| Day/Time | 4th Wednesday at 14:00 |
| Venue | The Staddy. |
The u3a Astronomy group are a lively bunch and meet at the Staddy on the fourth Wednesday of the month, commencing at 2 pm. If you are interested in the stars and the cosmos in general then do come along to our meeting.
At our meeting in February, we had a very lively discussion about Black Holes and a video showed us how stars can eventually turn into black holes. We particularly discussed the brightest and hungriest black hole ever detected, shown to the right, and which astronomers are currently looking at.
The most luminous object ever detected has been spied in the distant Universe and it is a quasar - the bright core of a galaxy that is powered by a gargantuan black hole some 17 billion times the mass of our Sun, known as J0529-4351. Studying the light from the quasar allowed astronomers to assess not just its brightness but its distance, too. The term quasar is used by astronomers to describe a particular type of Active Galactic Nucleus. It's the very energetic core of a galaxy which is being powered by an immense black hole that's pulling matter towards itself at a prodigious rate. As this material is accelerated around the hole, it is torn apart and emits a huge amount of light, so much so that even an object as distant as J0529-4351 is still visible to us. This quasar's light has taken a staggering 12 billion years to reach us.
Scientists, say this black hole has a voracious appetite, consuming the mass equivalent to our Sun every day, which is an enormous rate. And that makes it very, very luminous. The brightness is described as being equivalent to more than 500 trillion suns. The hot accretion disc producing all that light, measures seven light-years in diameter. That's roughly 15,000 times the distance from the Sun to the orbit of Neptune. All galaxies seem to have a supermassive object at their core, which probably means such objects are intrinsic to the evolution of those galaxies. “In simple language, it means that without these black holes, our galaxy as we know it wouldn't be what it is today”. The puzzle is, how some of the black holes got so big so early in the Universe?
Lots of information and suitable internet links are circulated and members can use this information for their own research. If you are interested in the stars, space or the universe in general, then do come along and be amazed at what we discuss, or contact Roy Fairclough, details above, for a chat.