Simply put;
Are we able to make any observations of the individual stars in other galaxies?
Is the depth of our scientific knowledge on star systems, based solely on stars in the Milky Way Galaxy alone?
Today, I just had a realization on how big the distance to any other galaxies are compared to the stars in our own Galaxy. I have been into space/pop-sci since I was a kid. I never thought about how limiting that huge gap must be in terms of astronomy.
Then I thought, Is this knowledge so easy to miss?
I have been pondering questions like Fermi Paradox, Drake Equation for many many years without this core awareness regarding observational limitations on stars in other galaxies.
But in light of this observational limit on individual star systems in other galaxies, many popular science concepts…just feels overly confident.
For example; Dark Energy or Dark Matter.
Did we come up with all of those cosmological theories purely/entirely based on detailed observation in our own Galaxy alone?
Best Answer
Just today, a new record was established in a brand new paper reporting the discovery of an observable star almost as distant in the Universe as it is possible to see. The discovery was possible due to a fortuitously placed cluster of galaxies whose gravity acts as a lens, focusing the light of the star in our direction.
Observations of stars in external galaxies are commonplace in astronomy. Of course, the dimmest stars are only observable in our own galactic neighborhood, but brighter stars are observable farther away.
As for dark energy and dark matter, dark energy has no measurable effect on our galaxy: its effects are only seen on much larger scales. Dark matter is very evident in clusters of galaxies, which don't contain enough visible matter to bind them together gravitationally.