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I wonder if a galaxy like this could be so bright as to support life on rogue planets i.e. those not orbiting a star? (If there would be any elements to create
by phaedrus 2y ago
I wonder if a galaxy like this could be so bright as to support life on rogue planets i.e. those not orbiting a star?
(If there would be any elements to create a rocky planet from. However the article states they were surprised to detect signs of dust and oxygen already in such an early galaxy.)
- kloch 2y agoOnly maybe in the dense core of a galaxy because incident radiation falls off with the square of distance. The nearest star to us after the Sun is ~4ly away, or ~250k AU. The Sun would have to be ~63 billion times brighter to give the same incident radiation at 250k AU, and that is just a typical distance between stars in our neighborhood . The Sun is also brighter than the average star, especially the older stars that congregate near the galactic center. Galaxies can easily have 1 trillion stars but they are usually so spread out as to make this impractical. This is also why the Milky Way, Triangulum, LMC, SMC, and Andromeda (nearest galaxies) are so faint to the naked eye.
- prawn 2y agoCarrying on from that first sentence: "in the center of the galaxy, stars are only 0.4–0.04 light-years apart" The most luminous stars going by Wikipedia are about 5 million times brighter than the Sun. Not sure if those are anywhere near galactic centres though.