Two words: neutron star
But the article is so simplistic that it's hard to tell whether they're comparing things by mass, or by diameter, or just aren't bright enough to realize that it matters.
But the article is so simplistic that it's hard to tell whether they're comparing things by mass, or by diameter, or just aren't bright enough to realize that it matters.
If, on the other hand, the comparison is by-mass, it's a different story.
All the best,
-HG