Sky Survey · NEOWISE 2014–2024 + SPHEREx 2025–26 · automated search

Billions of infrared detections. Which ones move?

NASA's NEOWISE telescope photographed every part of the sky about every six months for ten years. We cut the sky into 12,288 equal tiles and, tile by tile, a program links each source's detections across the years, measures how far and how steadily it moves, throws out artefacts, and checks ESA's Gaia catalogue: a mover that Gaia already knows is explained. Then SPHEREx, which mapped the whole sky again in 2025–26, gets a say: the program reads SPHEREx's all-sky spectral cube at the spot where each unexplained mover should be by then, checks that it is there (and gone from where it was in 2014), and takes its 0.75–5 µm spectrum, looking for the methane dip and red colour of a cold brown dwarf. Whatever is left is ranked, so people can look at the most promising candidates first. A candidate is a lead, never a discovery.

NEOWISE measures the motion (2014–2024). SPHEREx has no source catalogue yet, so the program measures its DR1 cube directly; its ~13″ pixels confirm only fast motions (about 1″ a year or more) and can blend close neighbours.

Detections searched

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Sources linked across years

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Sky searched

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Movers found

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Unexplained by Gaia

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Confirmed by SPHEREx

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Computer time

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