What do scientists compare current observations against to locate new celestial objects?

Scientists use star charts as a primary tool to compare current observations when searching for new celestial objects. Star charts are detailed maps of the night sky that illustrate the positions of stars, galaxies, and other celestial bodies. By utilizing these charts, astronomers can track changes in the sky over time and identify areas that may contain previously undiscovered objects.

When new observations are made, astronomers can reference star charts to see what is expected to be present in a given area of the sky. This process allows them to detect anomalies or new entities that were not recorded previously. The information in star charts is foundational to modern astronomy, serving as a reference point for locating and categorizing celestial objects.

Other methods, such as mathematical equations, historical texts, or satellite imagery, can provide valuable context or supplemental information, but they do not serve as the direct comparative tool that star charts do in locating new celestial objects.