Science & classification · News English
Can a white dwarf look green?
A familiar name does not describe every possible colour.
Read the story, check the words, then answer the questions and speak.
When a name can mislead
Does the name white dwarf guarantee that the star would look white?
1A name can describe a group without perfectly describing every member. NASA’s Astronomy Picture of the Day for 22 October asks readers to reconsider the colours of white dwarf stars. Its featured illustration concerns the star WD J1330+6435.
2White dwarfs are small, faint remnants left after stars like the Sun use up their nuclear fuel. Most stars appear white, with some noticeably red or blue. Their colours usually relate to temperature: blue stars are hotter than red ones. But the new explanation describes another influence in some white dwarfs.
3Small amounts of material collected by a star can interact with its atmosphere and change its normally white colour. According to the report, some white dwarfs would appear yellow, green, cyan, pink or purple. These objects are too faint to see with the unaided eye, so the explanation is not an invitation to find an obvious green point in tonight’s sky.
4The illustration on the NASA source page is an artist’s view, not a photograph of a green stellar surface. Our background Hubble photograph shows a different system, Sirius A and its faint white dwarf companion Sirius B, in 2003. It does not show WD J1330+6435.
Original teaching summary. Models and learning examples are illustrative, not news quotations.
Word help · Three useful words
Read the meanings and examples. Choose one word to use in your own sentence.
remnant
something left after a larger object or process has changed
The remnant tells us about the earlier star.
faint
giving little light or difficult to see
The faint star needs a telescope.
atmosphere
the gas surrounding a planet or star
The atmosphere affects the light we receive.
Check your reading · Three questions
Choose one answer for every question, then check. You can change an answer and check again.
Useful English
Although the class is called white dwarfs, some examples could appear green. Some limits the claim; could avoids turning a possibility into a certainty. This is a practice paraphrase, not a quotation.
Speak for 20 seconds
Describe a familiar category with an exception. Use usually, some or although.
Speak: your ideas
Describe a familiar category with an exception. Use usually, some or although.
Labelled model answer
Model: Although many libraries are quiet, some have areas for conversation. A general label does not describe every room.
Illustrative learning example, not a news quotation.
Alone: repeat without the model. Tutor: ask a follow-up question.
Mastery check · Three questions
Choose one answer for every question, then check. You can change an answer and check again.
Sources and reporting date
NASA Astronomy Picture of the Day visibly dated 22 October 2026. Exact time and timezone unstated; earliest worldwide start used conservatively: 21 October at 10:00 UTC. The featured APOD artwork is not reproduced.
- APOD: The First Green Star, WD J1330+6435
NASA Astronomy Picture of the Day visibly dated 22 October 2026. Exact time and timezone unstated; earliest worldwide start used conservatively: 21 October at 10:00 UTC. The featured APOD artwork is not reproduced. - Photograph source
Archive Hubble observation, 15 October 2003: Sirius A and Sirius B. Not WD J1330+6435; bright rings and spikes are instrument artifacts.