If a chart lists Pallas, Juno, or Vesta, you are looking at asteroid names. What do those extra names tell you?
Real objects orbiting the Sun
Asteroids are rocky objects that orbit the Sun. Most are in the asteroid belt between Mars and Jupiter. They exist independently of the meanings astrologers give them.
Read the name beside the position
Pallas, Juno, and Vesta are three individual asteroids. On a birth chart, each name identifies the object whose position is being shown. It is not another zodiac sign.
An optional part of some readings
Some modern Western astrologers use asteroid positions as additional symbols alongside the Sun, Moon, and planets. You can begin with those familiar bodies and explore asteroids later.
A few common questions
Does adding more asteroids make a prediction more reliable?
More objects add more positions to a chart. That alone does not establish that an interpretation or prediction is more reliable.
Sources & further reading
Astrology sources describe their own traditions and methods; they do not establish predictive accuracy. The writing exercises are original Lodestar editorial material.