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Astronomy Picture of the Day
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
OriginalAnnotated New Ghosts Revealed in Cassiopeia Explanation: Jinkies, look at all those ghosts! It took 100 hours of observation and a special oxygen filter for today’s image to capture three faint nebulas hidden in the Cassiopeia constellation. IC 59 and IC 63, the original Ghosts of Cassiopeia, haunt the region near multi-star system γ Cassiopeia. Energetic light from γ Cassiopeia causes the hydrogen gas in IC 59 and 63 to glow red. Their dust reflects and scatters some blue-ish white starlight. Newly discovered Objects 1, 2, and 3 appear as blue phantoms, revealing the presence of ionized oxygen. But ionized by what? Like at the bow of a speeding boat, γ Cassiopeia may be piling up material as the system moves through interstellar gas and dust. It follows that Object 3 may be the compressed and heated oxygen of that bow shock. Object 1 could be a planetary nebula if a central white dwarf is identified. The origins of these astronomical apparitions remain a mystery to be solved.
Tomorrow’s picture: it’s not easy being green
Date: October 21, 2026 Credit & Copyright: Louis Leroux-Géré, Thibault Rouillée, Vincent Martin, Cédric de Decker (Starfront Observatories) Authors & editors: Keighley Rockcliffe, Robert Nemiroff, Jerry Bonnell, Cecilia Chirenti A service of: ASD at NASA / GSFC,
NASA Science Activation & Michigan Tech. U.
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Yesterday’s Image APOD: 2026 October 20 – An Anticrepuscular Rainbow Fan
