One vital part of science is sharing our research with each other. One of the main ways this is done is via articles in journals. These are more specialized than magazines, and have fairly strict editorial policies. You've probably heard of some scientific journals -- the New England Journal of Medicine (I don't publish in that one), Science, and Nature are all mentioned in news articles almost daily. In astronomy we have our own subset of journals, such as the Astrophysical Journal, the Astronomical Journal, Astronomy and Astrophysics, and many, many others.
I am wrapping up some research this week, so I am preparing to write up the work to publish in a journal. Like other authors, we don't just sit down and start typing. I have written up an outline for the paper; I'm collecting my data for tables in the paper; I'm trying to clean up some loose ends in the research, and so on. It's quite a lot of work and amazingly tiring. I work all day and go home with part of a paragraph, a data table, and a partially-finished graph. But it is all necessary -- I can talk about what I've discovered until I am blue in the face, but until those data appear in print (meaning that an independent scientist or two has checked things over), other astronomers won't fully believe it.