Infographic of the Day: How Galaxies are Classified by Typeastronomer edwin hubble
After Hubble measured the distance to individual galaxies, he went on to measure their Doppler shift— how much light from the galaxies was stretched out due to their motion. He determined that galaxies all around the Milky Way are moving away from us at terrific speeds. The farther away the...
So, how many galaxies are in the universe? In this article, we'll find out how galaxies were discovered and what types exist, what they're made of, their internal structures, how they form and evolve, how they're distributed across the universe, and how active galaxies might emit...
Hubble studied galaxies and classified them into various types of elliptical and spiral galaxies. The spiral galaxies were characterized by disk shapes with spiral arms. It stood to reason that because the Milky Way was disk-shaped and spiral galaxies were disk-shaped, the Milky Way was probably...
There's actually an in between category... where a few objects can be legitimately classified as either big globulars or small elliptical galaxies. And the expected long term fate would likely be a relatively whimpering wind-down to to a quasi-stable ball of extremely old stars... punctuated...
Minsley and collaborators found that within galaxies with active black holes, the ISM is warmer, the ratios of warm molecular gas to other coolants are larger, and other features from dust particles have a wider range of values than in galaxies where the black holes are dormant. ...
Every active device in space is dealing with such risks right now – be itRosetta the comet chaseror the satellite responsible for streaming live sports. These cause many problem for designers of space instruments, on which millions of taxpayer’s money is spent and which are out there to col...
Statistics are drawn from populations, but a “population” doesn’t necessarily mean a physical count of bodies. It can be a collection of just about anything you can count, from galaxies in the sky to a count of trials in an experiment. Thus a statistic can be any quantity calculated fr...
the story is more complicated. When cool stars are inactive, the abiogenesis zone is too close to the star to overlap with the habitable zone. But cool stars can also be very active, producing large and frequent flares. Are these flares sufficient to drive the chemistry that leads to life'...
"We don't have a direct way to measure the distance to other galaxies," Miller explained. "Most galaxies are actually moving away from us. If there is a Type Ia supernova in a distant galaxy, we can use it to measure a combination of distance and velocity that allows us to determine...