# # Program information file # PROGRAM_ID 2021B052 PROGRAM_TITLE The Nature of a New Eruptive Variable Star and its Nebula PROGRAM_INV1 Mark Rushton PROGRAM_INV2 Marcel Popescu PROGRAM_INV3 Thomas Geballe PROGRAM_INV4 Aneurin Evans PROGRAM_INV5 Ruxandra Toma PROGRAM_SCICAT stellar PROGRAM_ABSTRACT_BEG NGCA-V84 is a recently discovered peculiar eruptive variable, surrounded by a rapidly changing nebula. Archival images show that it underwent an outburst in 2016, which was unnoticed at the time. Possible explanations for the behaviour of NGCA-V84 include rare phenomena. They are 1] a post Asymptotic Giant Branch [AGB] star undergoing a very-late thermal pulse, 2] a young stellar object experiencing a stellar merger, and 3] a hitherto unknown type of eruptive variable. All of these are very rare phenomena and therefore worthy of additional observations. We propose to obtain IRTF/SpeX 0.7-5.3 micron spectroscopy of NGCA-V8 to establish the current nature of the object and characterise the infrared [IR] emission line spectrum. We will also search for variability and a dust continuum in view of the strong rise in the mid-IR fluxes. PROGRAM_ABSTRACT_END