You were right the first time, Miss Perks. Astronomy and astrology are different.

In astronomy, the sun enters Scorpius on 23 November and leaves it again on 30 November. It then enters the constellation Ophiuchus, the serpent holder, where it will remain until it enters Sagittarius in December.

Astrology is perhaps best left to your Divination professor.

Antares is correct.

Ten points to Slytherin.