@article{52e7f88ff7294461b13fe7b21ed2a2f2,
title = "Near-infrared observations of active asteroid (3200) Phaethon reveal no evidence for hydration",
abstract = "Asteroid (3200) Phaethon is an active near-Earth asteroid and the parent body of the Geminid Meteor Shower. Because of its small perihelion distance, Phaethon{\textquoteright}s surface reaches temperatures sufficient to destabilize hydrated materials. We conducted rotationally resolved spectroscopic observations of this asteroid, mostly covering the northern hemisphere and the equatorial region, beyond 2.5-µm to search for evidence of hydration on its surface. Here we show that the observed part of Phaethon does not exhibit the 3-µm hydrated mineral absorption (within 2σ). These observations suggest that Phaethon{\textquoteright}s modern activity is not due to volatile sublimation or devolatilization of phyllosilicates on its surface. It is possible that the observed part of Phaethon was originally hydrated and has since lost volatiles from its surface via dehydration, supporting its connection to the Pallas family, or it was formed from anhydrous material.",
author = "Driss Takir and Theodore Kareta and Emery, {Joshua P.} and Josef Hanu{\v s} and Vishnu Reddy and Howell, {Ellen S.} and Rivkin, {Andrew S.} and Tomoko Arai",
note = "Funding Information: 1JETS/ARES, NASA Johnson Space Center, Houston, TX 77058-3696, USA. 2Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721-0092, USA. 3Department of Astronomy and Planetary Sciences, Northern Arizona University, Flagstaff, AZ 86011, USA. 4Institute of Astronomy, Charles University, CZ-18000 Prague 8, Czech Republic. 5Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20273, USA. 6Planetary Exploration Research Center, Chiba Institute of Technology, Narashino, Japan. 7Visiting astronomer at the Infrared Telescope Facility under contract from the National Aeronautics and Space Administration, which is operated by the University of Hawaii, Mauna Kea, HI 96720, USA. ✉email: driss.takir@nasa.gov Funding Information: D.T. was supported by NASA{\textquoteright}s Solar System Observations grant NNX17AJ24G. J.H. was supported by the grant 18-04514J of the Czech Science Foundation and by the Charles University Research program No. UNCE/SCI/023. V.R. and T.K. are supported by NASA Near-Earth Object Observations Grant NNX17AJ19G (PI: Reddy). J. P.E. was supported by NASA Near Earth Object Observations Grant NNX16AE91G. A.S.R. was supported by NASA Near Earth Object Observations Grant NNX14AL60G. We wish to thank NASA IRTF staff for their assistance with Phaethon observations. Spextool software is written and maintained by Mike Cushing at the University of Toledo, Bill Vacca at SOFIA, and Adwin Boogert at NASA InfraRed Telescope Facility (IRTF), Institute for Astronomy, University of Hawai{\textquoteright}i. NASA IRTF is operated by the University of Hawai{\textquoteright}i under contract NNH14CK55B with NASA. Publisher Copyright: {\textcopyright} 2020, This is a U.S. government work and not under copyright protection in the U.S.; foreign copyright protection may apply.",
year = "2020",
month = dec,
day = "1",
doi = "10.1038/s41467-020-15637-7",
language = "English (US)",
volume = "11",
journal = "Nature Communications",
issn = "2041-1723",
publisher = "Nature Publishing Group",
number = "1",
}