The coordinates for this episode point to something that is actually nothing. This location in the constellation Sagittarius is called Baade's Window, and unlike just about everything else in astronomy, this is actually notable for its emptiness. Well, it's sort of empty. If you look at this part of the sky, it's absolutely filled with stars in the Milky Way's bulge, and it also contains the globular cluster NGC 6522, but I will explain how it's actually empty.
Baade's Window is, as you may guess, named after someone other than Beniamin Markarian. The location is named after Walter Baade, an astronomer who was born in 1893 in Germany and educated there but who emigrated to the United States in 1931 to join researchers at Mount Wilson Observatory [1, 2]. In terms of geopolitics, Baade left Germany at a very good time, but when the United States joined World War II, he was identified as an enemy alien, and for a while, he cound not actually use the telescope at Mount Wilson [2]. Anyhow, when Baade could use the telescope or otherwise do research, he made quite a few notable discoveries, including identifying supernovae as a distinct class of objects [1, 2, 3], showing that stars could be divided into two separate populations based on their ages (which are now called Population I and Population 2 stars) [1, 2, 3], and making multiple refinements to the measurement of distances to both the center of our galaxy and to other galaxies [2, 3]. I quite honestly had not heard of Walter Baade before researching this episode, and I am surprised to learn about all of the important discoveries that he made. I suppose he may have been overshadowed by other people he was working with, like Edwin Hubble.
Relatively few astronomical objects are named after Walter Baade, but the most notable thing named after the astronomer is Baade's Window. As I mentioned before, one of Baade's achievements was to refine early measurements towards the center of the Milky Way. However, one of the challenges in doing this is that the Earth lies within the Milky Way's disk, which is filled not only with stars but also with interstellar gas and dust. The dust is notably problematic because it will either absorb or scatter the starlight passing through it, making stars look fainter and redder. Most of the bulge of the Milky Way as seen from Earth is only visible when looking through the interstellar dust in the Milky Way's disk, but Walter Baade managed to find a location about 1 degree in diameter (or two times the width of the Moon) in the direction of the Milky Way's bulge that was relatively free of dust. In other words, he found a hole in the Milky Way's interstellar dust through which he could clearly see the stars in the bulge at the center of the Milky Way. This is equivalent to being in a thunderstorm and somehow being able to see a patch of blue sky through a hole in the clouds.
Through this hole, which is now called Baade's Window, Walter Baade was able to identify a number of variable stars, including RR Lyrae stars [4]. These stars vary periodically in brightness in a way that is directly linked to their luminosity, so when Walter Baade was able to measure the period of the stars' variations and their relative brightness as seen from Earth, he could calculate the distances to the stars. Baade could do this calculation with the stars in Baade's Window in large part because the stars were unobscured by interstellar dust. If dust had been present, it would have made the stars look fainter, which in turn would have affected the distance measurement. In 1946, Walter Baade published a paper based on his observations indicating that the distance to the center of the Milky Way is "about 9 kiloparsecs", or 29400 light years [4]. Today, in the year 2025, we now know that the distance to the black hole Sagittarius A* at the center of the Milky Way is 8.178 kpc [5], so Walter Baade's measurement was quite good for the time, especially given the technology he was working with. These results also helped to prove that the Milky Way is a spiral galaxy with an intermediate-sized bulge and that the Solar System is located quite far away from the center of the galaxy in the spiral galaxy's disk. We take all of the for granted these days, but back in the 1940s, the exact nature of the Milky Way was still heavily debated.
However, research on Baade's Window would continue long after Walter Baade's 1946 distance measurements. Many other astronomers who want to understand the stars in our galaxy's bulge now routinely go look in (or maybe through) Baade's Window to examine them, including understanding their chemical composition [5, 6, 7, 8], which differs from the chemical compisition of the Sun and other nearby stars, understanding the motions of stars in the bulge [5, 7, 9, 10, 11], and understanding the variable stars originally found by Walter Baade [9, 12]. A lot of this work also includes the globular cluster NGC 6522 [13, 14, 15,16, 17, 18, 19, 20, 21, 22], which, as I mentioned earlier, sits within Baade's Window. If people want to study a globular cluster without worrying about its stars being partially obscured by dust, then NGC 6522 is an ideal choice. Still, I think the most revolutionary work that will ever be done with observations of Baade's Window will be Walter Baade's 1946 publication of the distance to the center of the galaxy.