Main-Belt Comet P/2012 T1 (PANSTARRS)

TL;DR

This study characterizes main-belt comet P/2012 T1 through extensive observations and simulations, revealing its brightness variation, low gas emission, and stable orbit linked to the Lixiaohua asteroid family.

Contribution

It provides the first detailed observational and dynamical analysis of P/2012 T1, including brightness evolution, spectroscopic limits, and orbital stability, establishing its nature as a main-belt comet.

Findings

Brightness approximately doubles then decreases by 60%

No evidence of hydrated minerals or CN emission

Dynamically stable for over 100 million years

Abstract

We present initial results from observations and numerical analyses aimed at characterizing main-belt comet P/2012 T1 (PANSTARRS). Optical monitoring observations were made between October 2012 and February 2013 using the University of Hawaii 2.2 m telescope, the Keck I telescope, the Baade and Clay Magellan telescopes, Faulkes Telescope South, the Perkins Telescope at Lowell Observatory, and the Southern Astrophysical Research (SOAR) telescope. The object's intrinsic brightness approximately doubles from the time of its discovery in early October until mid-November and then decreases by ~60% between late December and early February, similar to photometric behavior exhibited by several other main-belt comets and unlike that exhibited by disrupted asteroid (596) Scheila. We also used Keck to conduct spectroscopic searches for CN emission as well as absorption at 0.7 microns that could indicate the presence of hydrated minerals, finding an upper limit CN production rate of QCN<1.5x10^23 mol/s, from which we infer a water production rate of QH2O<5x10^25 mol/s, and no evidence of the presence of hydrated minerals. Numerical simulations indicate that P/2012 T1 is largely dynamically stable for >100 Myr and is unlikely to be a recently implanted interloper from the outer solar system, while a search for potential asteroid family associations reveal that it is dynamically linked to the ~155 Myr-old Lixiaohua asteroid family.