Cosmology with the SPHEREX All-Sky Spectral Survey · HackerPapers discussionshttps://hackerpaper.kaipfister.de/p/1412.4872/Collected HN comments and submissions linking this paper.enMon, 02 Nov 2026 11:16:22 GMTCosmology with the SPHEREX All-Sky Spectral Survey — mentioned by mturmonhttps://news.ycombinator.com/item?id=43339331urn:hackerpapers:mention:1412.4872:43339331Wed, 12 Mar 2025 02:23:29 GMT<p>A nearby (excellent) comment (https://news.ycombinator.com/item?id=43338459) gives further context, but: the 6-month revisit period is just an artifact of the Earth-orbit-based sky scanning strategy. In 6 months the satellite, precessing at 1 degree/day, and facing away from the sun during data collection, will scan the sky completely. (See Fig 1 of the paper [0]). So in particular, the 6-month period is not to revisit these distant galaxies more than once to observe spectral changes. The strategy, indeed, is to “stack” the multiple exposures to beat down noise. (Fig.6 of [0], top left). It…</p><p><a href="https://hackerpaper.kaipfister.de/p/1412.4872/">Paper and discussion history</a>. A mention is not an endorsement.</p>astro-ph.CO