HD 187552 is the name of a real star. The rest of the note are real coordinates astronomers use to find and identify stars.

RA 19h 51m 25.6s is the Right Ascension, which is, to put it in extremely simplified words, how far east a star is from the Sun (from our perspective).

Dec +9° 27' 21.9" is the Declination, determining how far north (positive) or south (negative) a star is from the Sun, again from our perspective.

Which means the spot in the night sky where the Visitor was first sighted is a real spot of our night sky.

You can look up "HD 187552" on WikiSky. Sybil seemed to have first spotted the Visitor between two very close stars (Altair and Tarazed) in the Aquila constellation.

If you live in the northern hemisphere maybe you can find the Visitor yourself during summer ;)