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

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NASA’s Astronomy Picture of the Day for October 22, 2026, features an illustration of the white dwarf WD J1330+6435 surrounded by an accretion disk. The accompanying explanation says astronomers have found that trace elements accreted by some white dwarfs can shift their normally white appearance into colors including green; the stars are too faint to see with the naked eye.

NASA’s Astronomy Picture of the Day for October 22, 2026, features an illustration of WD J1330+6435, a white dwarf surrounded by an accretion disk of gas and rocks. The accompanying explanation describes findings that trace elements gathered by some white dwarfs can change their normally white appearance, with colors that may include green; these faint stars are not visible to the unaided eye.

The image is an illustration, not a direct photograph of a star whose green color has been resolved by eye. NASA describes WD J1330+6435 as a white dwarf with material orbiting it in an accretion disk. The picture’s title, “The First Green Star,” draws attention to the possibility of unusual stellar colors, but the supplied explanation does not say the object appears vividly green as a point of light in the night sky.

According to the NASA APOD explanation, astronomers recently found that some white dwarfs may appear yellow, green, cyan, pink or purple. The proposed color shift comes from trace elements that have been accreted onto the stars and interact with their atmospheres, altering the white appearance expected of a white dwarf. The source does not identify the specific elements responsible for WD J1330+6435’s color or provide measurements of its apparent hue.

White dwarfs are the compact remnants left after stars like the Sun exhaust their nuclear fuel. NASA notes that they are small and faint. Although the colors of stars are commonly associated with temperature, the APOD explanation says the unusual colors described here involve atmospheric effects from accreted material, rather than presenting green as a typical stellar temperature category.

Why White Dwarfs Can Look Green

The APOD’s point is that a star’s apparent color can reflect more than its basic temperature. For these white dwarfs, NASA’s explanation connects the color change to trace material in the atmosphere. That makes the featured object a useful illustration of how a star’s surroundings and accumulated matter can affect the light astronomers observe.

The finding also puts a limit on the familiar idea that stars are simply blue, white or red. The additional colors described by NASA are not a promise of spectacular green stars visible overhead: the stars are too faint to see tonight, as the APOD explanation puts it. Their colors are relevant as an astronomical observation, even when they cannot be picked out by the naked eye.

From Stellar Color to Accreted Matter

For most stars seen from Earth, distance makes them appear as points rather than disks. NASA’s explanation says they are mostly perceived as white, though some are noticeably red or blue, colors that typically relate to temperature: blue stars are hotter than red stars. That broad relationship provides a starting point for the APOD’s question about whether stars can appear in other colors.

WD J1330+6435 is presented as a white dwarf, the leftover core of a star like the Sun after it runs out of nuclear fuel. The accompanying artwork depicts an accretion disk, a ring of orbiting gas and rocks. NASA’s explanation links material accreted by some white dwarfs with changes to their atmospheric light, setting the image within a wider discussion of how matter around a stellar remnant can affect its observed color.

What the APOD Does Not Specify

The supplied NASA explanation does not provide the underlying study’s authors, publication details, methods, or data, and it does not describe how the colors were measured. It also does not specify which trace elements affect WD J1330+6435, whether that particular white dwarf has a confirmed green appearance, or how strong its color shift is. The title’s wording should not be taken as evidence that the star is visibly green to observers on Earth.

The illustration is explicitly presented as an illustration, so it should not be read as a direct color image of the star and disk. NASA says some white dwarfs would appear in a range of colors, but the source material does not clarify whether “The First Green Star” means WD J1330+6435 is the first object identified with that appearance or is a descriptive title for the feature.

Further Details on the White Dwarf

The October 22 APOD entry points readers to the next day’s picture, titled “Eye in the Sky.” For more detail on the color findings, readers would need the research publication or additional information from NASA; neither is provided in the source material supplied for this report. Until those details are available, the confirmed account is limited to NASA’s explanation that accreted trace elements can shift the apparent colors of some white dwarfs.

Key Questions

What is WD J1330+6435?

NASA identifies WD J1330+6435 as a white dwarf, the small, faint remnant left after a star like the Sun exhausts its nuclear fuel.

Is the APOD image a photograph?

No. NASA describes the featured image as an illustration showing the white dwarf and an accretion disk of gas and rocks.

Why might some white dwarfs look green?

NASA’s explanation says trace elements accreted by some white dwarfs interact with their atmospheres and shift their normally white color. The source does not name the elements responsible for WD J1330+6435’s appearance.

Can people see WD J1330+6435 as a green star?

Not with the unaided eye, according to the APOD explanation, which says these stars are too faint to see tonight.

Does the source confirm WD J1330+6435 is the first green star?

The APOD title calls the feature “The First Green Star,” but the supplied explanation does not establish what “first” refers to or give a detailed account of the object’s measured color. It does say that some white dwarfs may appear green among other colors.

Source: primary