Bad Astronomy 7 Nov 2018, 14:00 UTC Is 'Oumuamua, the weird object from interstellar space that barreled through our solar system late last year, an alien spaceship? Spoiler: No. Well, almost certainly "no." I can't say unequivocally that it's not, but I can say that I would bet a lot of money against it.
Was Oumuamua A Solar Sail From An Alien Civilization That Flew Past Earth Last Year? Entertaining But Implausible Suggestion6 Nov 2018, 18:18 UTC It's an entertaining but rather far fetched proposal in an arxiv preprint not published anywhere but mentioned in a Scientific American op ed. Implausible for many reasons including its spectrum which is not the shiny spectrum you'd expect from a solar sail but the red of tholins mixed with rock and metal as you'd expect from an asteroid / comet.
Starts With a Bang! 6 Nov 2018, 15:01 UTC Three times in the past 1,000 years, a portion of humanity has looked up at our night sky, only to be surprised by the sudden appearance of a new, dazzling, brilliant star. The previously-unseen point of light materializes in the sky, appears to brighten for a time, and then slowly fades over the course of months or even years. Eventually, it fades away entirely. Originally called a stella nova (for “new star”) by Tycho Brahe in 1572, these events are now recognized as supernovae, where a massive star or stellar corpse undergoes a runaway fusion reaction, brightening tremendously and illuminating the stellar debris surrounding it. For many years, scientists broadly categorized them in two different ways: either arising from stellar remnants or from the core collapse of a massive star. We’ve learned so much more about the life-and-death of stars, though. We now know there are six different ways to make a supernova.
Bad Astronomy 6 Nov 2018, 14:00 UTC Our Milky Way galaxy grows by eating other galaxies. We know this for many reasons. For one, we can see other galaxies colliding and merging all over the sky. For another, we can track stars on our galaxy that were once part of another galaxy, but were absorbed into our own. These are usually relatively recent events involving a much smaller galaxy. But a new result changes that. By mapping huge numbers of stars in the galaxy, astronomers have found compelling evidence that the Milky Way ate a galaxy that was, at the time, about a quarter its size. And that time was a staggering ten billion years ago. Yeah, this is very cool.