Did you know that more than two-thirds of stars are part of multiple systems, where two or more stars orbit a common center of Gravity? This means that the Sun is one of the minority, being on its own. Most of the multiple systems out there are in fact double star systems, but some of them are triples and a few are quadruples. One such quadruple star system, known as DI Cha (in the chameleon constellation), was recently imaged by Hubble. The system lies in the southern constellation of Chameleon, about 520 light years away. The quadruple system is a...
1,200 Km / s. That’s fast. Fast enough to race around the entire Earth in 30 seconds. Except that it’s not a bullet, it’s a star, larger and more massive than the Earth. And a multinational team of astronomers has discovered it, and more importantly, where it came from and why it’s moving so fast. Hypervelocity stars (HVS’) are an uncommon phenomenon, since the conditions necessary to accelerate them to incredible speeds are rare. There are only about 20 HVS known, and the first was found only ten years ago. So where do they come from? There are only a...
When I do Planetarium shows, one of the things I like to talk about during the Milky Way – Andromeda collision that will happen in 70 Mlllion years, is the fact that very few stars will actually hit each other. Yet we still call it a ‘Galaxy collision.’ One of the questions I always get is “Will the Earth survive this?” I usually ask the audience. The response is usually a unanimous ‘No way!” And then I tell them how big Galaxies are and they can’t believe how unlikely it is that the solar system will be affected. Consider the...
