@article{0f93010c284d458aa56716ad304a795d,
title = "The reactivation of main-belt comet 259P/Garradd (P/2008 R1)",
abstract = "We present observations of main-belt comet (MBC) 259P/Garradd from 4 months prior to its 2017 perihelion passage to 5 months after perihelion using the Gemini North and South telescopes. The object was confirmed to be active during this period, placing it among seven MBCs confirmed to have recurrent activity. We find an average net pre-perihelion dust production rate for 259P in 2017 of Md = (4.6 ± 0.2) kg s-1 (assuming grain densities of ρ = 2500 kg m-3 and a mean effective particle size of a¯d = 2 mm) and a best-fit start date of detectable activity of 2017 April 22 ± 1, when the object was at a heliocentric distance of rh = 1.96 ∓ 0.03 au and a true anomaly of ν = 313°.9 ± 0°.4. We estimate the effective active fraction of 259P{\textquoteright}s surface area to be from fact ∼ 7 × 10-3 to fact ∼ 6 × 10-2 (corresponding to effective active areas of Aact ∼ 8 × 103 m2 to Aact ∼ 7 × 104 m2) at the start of its 2017 active period. A comparison of estimated total dust masses measured for 259P in 2008 and 2017 shows no evidence of changes in activity strength between the two active apparitions. The heliocentric distance of 259P{\textquoteright}s activity onset point is much smaller than those of other MBCs, suggesting that its ice reservoirs may be located at greater depths than on MBCs farther from the Sun, increasing the time needed for a solar-irradiation-driven thermal wave to reach subsurface ice. We suggest that deeper ice on 259P could be a result of more rapid ice depletion caused by the object{\textquoteright}s closer proximity to the Sun compared to other MBCs.",
author = "Hsieh, {Henry H.} and Masateru Ishiguro and Knight, {Matthew M.} and Moskovitz, {Nicholas A.} and Sheppard, {Scott S.} and Trujillo, {Chadwick A.}",
note = "Funding Information: We are grateful to two anonymous reviewers who helped to improve this manuscript. H.H.H., M.M.K., N.A.M., and S.S.S. acknowledge support from the NASA Solar System Observations program (grants NNX16AD68G and 80NSSC19K0869). We are grateful to J. Chavez, J. Fuentes, M. Gomez, A. Lopez, L. Magill, E. Marin, K. Roth, D. Sanmartim, A. Shugart, K. Silva, A. Smith, and E. Wenderoth for assistance in obtaining observations. This research made use of astropy, a community-developed core python package for astronomy, and uncertainties (version 3.0.2), a python package for calculations with uncertainties by E. O. Lebigot. This work benefited from support by the International Space Science Institute in Bern, Switzerland, through the hosting and provision of financial support for an international team, which was led by C. Snodgrass and included H.H.H. and M.M.K., to discuss the science of MBCs. This work is based on observations obtained at the Gemini Observatory (Program IDs GN-2013A-Q-102, GS-2017A-LP-11, and GS-2017B-LP-11), which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the National Research Council (Canada), CONICYT (Chile), Ministerio de Ciencia, Tecnolog{\'i}a e Innovaci{\'o}n Productiva (Argentina), and Minist{\'e}rio da Ci{\^e}ncia, Tecnologia e Inova{\c c}{\~a}o (Brazil). This work is also based in part on data collected at Subaru Telescope and obtained from the SMOKA, which is operated by the Astronomy Data Center, National Astronomical Observatory of Japan. We wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Maunakea has always had within the indigenous Hawaiian community. We are fortunate to have the opportunity to conduct observations from this mountain. Publisher Copyright: {\textcopyright} 2021. The Author(s). Published by the American Astronomical Society.",
year = "2021",
month = apr,
doi = "10.3847/PSJ/abe59d",
language = "English (US)",
volume = "2",
journal = "Planetary Science Journal",
issn = "2632-3338",
publisher = "IOP Publishing Ltd.",
number = "2",
}