Is God referencing constellations in Job 38?

Yes, he is.  Chapter 38 of Job tells us about how God talked to Job with the purpose of reminding Job about how small his own wisdom and power was when compared to that of God.   God starts this off in chapter 38 by first asking Job, “Where were you…” when I created the world and universe, and he goes into great descriptive detail concerning many aspects of nature and the universe in this chapter.

He specifically mentions both creating and supervising the constellations in chapter 38.  They’re first mentioned in a general sense as “the morning stars” (v. 7), but if you skip down to verses 31-32 you’ll see that he lists several of them specifically by name:

The Pleiades, also called the Seven Sisters.  Their more official name in astronomy circles is Messier 45 or M45.  This is the constellation which we can most easily see without a telescope.

Orion, which we’ve all probably heard of.  It’s one of the most recognizable constellations, seen best during winter evenings.  When I was driving out west a few days ago, I saw it very easily at night time, especially when I was out in the middle of nowhere with no street lights around.

God also mentions “the Mazzaroth.”  This is a Hebrew word which means “constellation.”  Some believe this might refer to the 12 zodiac signs:  Aries, Leo, Sagittarius, Taurus, Virgo, Capricorn, Gemini, Libra, Aquarius, Cancer, Scorpio, Pisces

He also mentions “the Bear.”  This would refer to either Ursa Major or Ursa Minor, or both.  Ursa Major is known as the Great Bear in astronomy, and Ursa Minor is known as the Little Bear.  The Big Dipper is part of Ursa Major; it’s actually the tail of the Great Bear.  The Little Dipper is part of Ursa Minor; it’s actually the tail of the Little Bear.  Polaris is the end of the tail of the Little Bear.

So yes, constellations are specifically mentioned in Job 38.