IRTF Data Archive Program Information

# # Program information file # PROGRAM_ID 2021B014 PROGRAM_TITLE Occasional Triton spectra 2020-2023 for rotational and seasonal variability PROGRAM_INV1 Leslie Young PROGRAM_INV2 William Grundy PROGRAM_INV3 Bryan Holler PROGRAM_INV4 Eliot Young PROGRAM_INV5 Glenn Orton PROGRAM_SCICAT solar system PROGRAM_ABSTRACT_BEG We propose to continue our observations of Triton's 0.8-2.5 micron spectrum with IRTF/SpeX in SXD mode, to study the short and long-term variability of Triton's surface ices, to study their composition, temperature, mixing state, and grain size. This long-running program includes baseline campaigns that sample Triton's rotational variation approximately every five years with occasional runs in the intervening semesters. This proposal is for occasional runs, since we just completed a successful baseline run in 2019B. We will soon see the end of Triton's southern summer, with sub-solar latitudes ranging from -37 deg in July 2020 to -32 deg in Nov 2023. Continued spectra can be used to [i] detect transient anomolies, if any, [ii] decouple migration from viewing geometry, and [iii] search for new ices at newly exposed latitudes. The observation strategy will closely mirror that of Grundy and Young 2004 [Icarus 172, 455-465], Grundy et al. 2010 [Icarus 205, 594-604], and Holler et al. 2016 [Icarus 267, 255-266]. In 2019B, we began saving serendipitous Neptune cloud imaging, and we now add Glenn Orton to the program. PROGRAM_ABSTRACT_END