Phase curves at small phase angles of bodies from the SLOAN Moving Objects Catalog

Abstract

<p>Phase curves of small bodies are useful tools to estimate sizes and, together with complementary theoretical and laboratory results, to understand their surfaces' micro and macroscopic properties. Although we can observe asteroids up to phase angles of about 30 degrees, the range of phase angles covered by outer solar system objects usually does not go further than 7 to 10 degrees. In this work, we aim to directly compare the phase curves of asteroids observed with low-phase angles with these of outer solar system objects, namely, trans-Neptunian objects and Centaurs.</p> <p>We used data from the SLOAN Moving objects catalog assuming a simple linear model to compute absolute magnitudes and phase coefficients in the ugriz system, plus V and R filters.</p> <p>We obtained absolute magnitudes in all filters for more than 4000 objects. Our comparison with outer solar system objects points to the common property of the surfaces: intrinsically redder objects become blue with increasing phase angle, while the opposite happens for intrinsically bluer objects.</p>