The same is true in Chinese and Japanese. The term "星" refers to heavenly bodies in general. To specifically refer to planets, in Japanese they use the term "Wakusei" (惑星) which literally means "wandering star".
In Chinese the term used for planet seems to be "行星" which has the same meaning (In fact all the terms can be used in both China and Japan, they are just rarer in some regions).
The problem, at least in Japanese, is that since the term "planet" still carries the kanji for "star", when they want they just reduce the term to just "星" while still carrying the reading of "sei" to refer to something being a planet, it's easier to notice that when it's reading because it's different from Hoshi. But sometimes they still are read as Hoshi even if the intended meaning is Wakusei, and that is when confusion arises. But it's false to say that in Japanese or Chinese there are no words to refer to planets and stars differently, there are, it's just that most writers and people, in general, prefer to reduce the number of things you need to read/listen to if the context is specific enough. It's no different to how they, for example, can write entire dialogue without any mention of pronouns because you are supposed to understand by context alone, or using words without the specific use of plural (That yes, does exist in Japanese, and I suppose that is the same in Chinese).
The term used here seems to be "
星辰". The first is the character of the celestial body/star. The second "辰" is yet another general term for celestial body. So it's just reinforcing the idea that it's a celestial body.