Every single massive galaxy has a black hole at its center, and bigger galaxies have bigger black holes. It almost seems like a natural progression, with a bigger galaxy meaning more stars and material to feed a bigger black hole. However, most of that material doesn’t make it to the central black hole. So how does a massive galaxy with hundreds of billions of stars spread out over hundreds of thousands of light years contribute to a black hole that at most is solar system sized? The answer might lie in another elusive and enigmatic gem of the universe: Dark...
Space is Big. I say this often, but it is so vast we can’t even comprehend the emptiness of it. We see Billions upon Billions of stars, all taunting us with their shine, seemingly close but completely unreachable. How do we know which stars we should spend our time looking at? We don’t really have the time to scan through each star in detail, so what are the criteria for taking a closer look? Generally we look at a population of stars to gain an understanding of each life stage, and then we look at the oldest and youngest to determine...
About 170 years ago, a star nearly exploded in the Southern constellation Carina. I say nearly for a few reasons. On Earth, observers saw a dim, seemingly-average star become the second brightest star in the night sky. It stayed that way for 20 years before slowly fading. When we looked at it with telescopes, we found that whatever happened to Eta Carinae, it ejected more than 30 times the mass of our Sun in that short twenty year period, creating what we now call the homunculus nebula. Eta Carinae is a multiple star system 7500 light years away from Earth, so rest assured any...
If you guessed that I was referring to the Pleiades, you are correct. The small open star cluster, Messier 45, is about 440 Light Years from Earth, relatively close for a star cluster. We are able to see it with the naked eye in Autumn and Winter here in the Northern Hemisphere. The stars in the Pleiades are young and bright blue, meaning they are very massive and hot. By young, I mean somewhere around a hundred Million Years, about 40 times younger than the Sun. The smears of blue in the above photo show that the cluster is still...
Dark Matter; Dark Energy; We basically use the term ‘dark’ as a cool sounding version of ‘We have no clue what this is.’ But Dark Matter is a better name than ‘We haven’t a clue’ Matter. Over the years, Astronomers have been trying to pinpoint what the stuff actually is that seems to permeate the universe and makes up 26.8% of the entire total energy-mass (Compare this to a paltry 4.9% of ordinary matter, ie the stuff we can see). But now, as per usual, theorists have come up with another possibility for the source of dark matter: moderately sized,...
