Not every clump of something needs to be a clump of matter.
What if binaries aren't just stars and planets/planetoids?
Originally posted by igigi
Acutally, I think the data at the BRI would say otherwise...
A brown dwarf star believed to be five times the size of Jupiter is theorized by scientists to have been behind the mass extinction of prehistoric life on earth 26 million years ago... and they believe that it might happen again.
comet-showerThis star, nicknamed Nemesis by NASA scientists, emits only infrared light and is practically invisible to many of our conventional star gazing tools, is believed to be traveling on a 26 million year orbit of our Sun (or roughly 25,000 times that of the Earth's orbit). it is theorized that this icy orb of death travels along it's abnormal orbit, it's massive gravitational pull dragging with it oortcloudpicasteroids and comets out of the Oort Cloud, a vast celestial sphere made up of rocks, ice balls, and space dust twice as far away from the earth as it is believed Nemesis is. [It's believed that many of our solar system's asteroids and comets come from the Oort Cloud.]
Is our Sun part of a binary star system? An unseen companion star, nicknamed “Nemesis,” may be sending comets towards Earth. Throughout history, such impacts could have had a profound effect on the evolution of the biosphere by causing regular mass extinctions. If Nemesis exists, NASA’s new WISE telescope should be able to spot it.
I am suggesting the whole galactic arm is in a spinning / rotating / spiralling motion.
The Hammar Axis is an imaginary centre point our sun appears to orbit as it spins with the Orion Spur.
Imagine drawing the imaginary centre axis of a whirlpool of water, it doesn't have to be a straight line.
48. Around what does the Sun revolve?
My almost 8 year young son Adam and I have a question about the revolution of the sun. We know that the planets revolve around the sun, and all have rotational periods also. We see that the sun aside from having a rotational period, also has a revolution of some 250 million years. We are curious what it is that the sun is revolving around?
I can only guess that your son came across a reference to the rotation of the galaxy. Many galaxies are round and rotate around their center, and presumably ours does too, and so the Sun and the solar system share that motion.
What do they rotate around? Good question. There is SOMETHING at the center of the galaxy, and radio astronomers have determined it is very compact--I read somewhere, smaller than the orbit of Saturn, or maybe Jupiter. It also seems massive, but does not shine brightly, and most astronomers favor a humongous black hole, created in the early years of the universe (yes, Adam, we are safe from it).
Still, what holds galaxies together is a bit of a mystery. If it were just the gravity of something pulling it towards the middle, a galaxy would rotate like the solar system--fast motion near the middle, slower and slower as one gets away. Vera Rubin has examined the light of galaxies and has determined (by the Doppler effect) that many of them, apart perhaps for the outer edges, rotate together, like a spinning dish, which is SLOWEST near the middle.
So, Adam, maybe the correct answer is: we do not know.