APOD: 2026 October 22 – The First Green Star, WD J1330+6435

NASA APOD Science APOD APOD: 2026 October 22 – The… Today’s APOD Archive Submissions Index Search Calendar RSS Education About Discuss   APOD 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. The First Green Star, WD J1330+6435 Explanation: Star light, star bright: is there a green star out tonight? Other than the Sun, all stars are so far from Earth that they appear as points in the sky. They are mostly white, but sometimes noticeably red or blue. This color typically relates to the temperature: blue stars are hotter than red stars. What about other colors? The featured image is an illustration showing WD J1330+6435, a white dwarf star, surrounded by an accretion disk with gas and rocks orbiting the star. White dwarfs are small, faint stars that are left over when a star like the Sun exhausts its nuclear fuel. Astronomers recently found that some white dwarf stars, despite their name, would appear yellow, green, cyan, pink, or purple. In these cases, trace elements that were accreted to these stars interact with the stellar atmosphere and shift its normally white color. But, alas! I wish I may, I wish I might, but they are too faint to see tonight… Tomorrow’s picture: eye in the sky Date October 22, 2026 Credit & Copyright Mark A. Garlick/University of Warwick Authors & editors: Cecilia Chirenti, Robert Nemiroff, Jerry Bonnell, Keighley Rockcliffe A service of: ASD at NASA / GSFC,NASA Science Activation & Michigan Tech. U. Random APOD Generator Yesterday’s Image APOD: 2026 October 21 – New Ghosts Revealed in Cassiopeia Tomorrow’s Image