Using Light Curves to Find Rotation Period of Asteroids Rotating Non-Spherical Near-Earth Objects -Samuel Pshyk, Timothy Gray

What is an Asteroid? Small rocky body ranging in size from 1000km to dust size particles. Orbits the Sun. Mostly found in orbit in the asteroid belt but some have orbits coming far closer to the Sun and by extension, the Earth.

What is a Near Earth Object? Any asteroid or comet that has an orbit about the sun, that intersects Earth's orbit. Potentially Hazardous Objects are a subset of these that have some greater remote chance of hitting the Earth.

Rotation Period How long does it take for the asteroid to rotate? Calculated by observing a light curve of an asteroid.

What is a Light Curve A Light Brightness vs time graph The brightness is based off of the exposed surface of the asteroid reflecting light. The more surface facing the light, the brighter the object will appear. The graph will have a period which will be the same period as the rotation of the asteroid.

2011 KF4 Discovered May 11,2011 Travels across the sky at a rate of 1.3 degrees a day Perihelion at 1.0056 AU Aphelion at 4.1984 Estimated size : Between 470m-970m Most recent pass by earth was September 16th, 2011 passing .1454730 AU to the Earth

Project Observe objects with undiscovered rotation periods. Use computer software to observe light variations as the asteroid moves across the night sky. Use light intensity vs. time graphs gathered from our data to figure out the rotation period of the asteroid.

Images

Light Curve Graph

Results Since our observations were in a one hour time frame, we were not able to see the full period of rotation.

Acknowledgments Special Thanks to: Dr. Joe Pollock Dr. Tashikori STEP Skynet