New answers tagged galaxy
6
Certainly - as planetmaker pointed out, it would be unlikely for satellite galaxies to lack these objects simply from a theoretical point of view. Let's take the Magellanic Clouds as an example, given how relatively well-studied they are. We know there are massive stars and star clusters in the Magellanic Clouds (R136 comes to mind) and there's no ...
1
There are several answers to this similar question:
https://astronomy.stackexchange.com/questions/42053/what-pulls-the-sun-above-the-galactic-plane-and-pulls-it-below-the-galactic-plan/42054#42054[1]
If I remember correctly, it takes tens of millions of years for the Sun to make one full oscellation "above" and "below" the galactic plane, ...
7
When you consider an expanding universe, the meaning of "distance" becomes difficult, and different reporters use different definitions.
In many newspapers the distance used is the "light travel time distance". This is the time that light has been travelling from the galaxy multiplied by the speed of light. So a galaxy that is 300 million ...
18
Two things.
The abundance of oxygen is a difficult thing to measure in optical spectra - much harder than Mg, Ca, and Si. So these latter are usually used to represent "the alpha elements". There is a strong OI triplet at 777 nm and a much weaker OI forbidden line at 630 nm. But these often give contrary results because they are blended with other ...
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