You can't say definitively which constellation is on the northern horizon without knowing when and where you are observing.

Here's why:

* Time of Year: The constellations visible in the night sky change throughout the year due to the Earth's rotation and revolution around the Sun.

* Location on Earth: The constellations visible in the northern hemisphere differ from those visible in the southern hemisphere, and the exact view depends on your latitude.

To determine which constellation is on the northern horizon, you need to:

1. Know the date and time: This helps determine the position of stars in the night sky.

2. Know your location: Your latitude determines which constellations are visible.

Helpful tools:

* Stargazing apps: Many apps like Stellarium or SkySafari will show you a real-time sky map based on your location and time.

* Online planetarium websites: Websites like the Night Sky Network (nightsky.jpl.nasa.gov) can also provide constellation information.

Let me know the date, time, and your approximate location, and I can help you identify the constellation on the northern horizon!