Talk:AG Carinae

NOT a Planetary Nebula

Looking at the SIMBAD entry for the star, I noticed a note about it being misclassified as a PN. The abstract for the Hubble observation of the object calls it a circumstellar shell. I didn't know if I should change it because I am not an astronomer and easily confused by these things. I do read a bit about these things when I process the images, though. Geckzilla (talk) 21:59, 4 September 2013 (UTC)

• You're correct about it not being a planetary nebula - that refers to a specific type of emission nebula formed by stars of no more than about 8 solar masses during their post-AGB evolution. At ~70 solar masses, there is no way the ejecta nebula around this star is a PN, even if it does (superficially) resemble one in some ways. 203.57.209.105 (talk) 16:14, 30 October 2014 (UTC)

References

10,000 years ago or 20,000 light years away?

Recent coverage of the Hubble Observatory's picture of the star (e.g. SciTechDaily) talks about "One or more giant eruptions 10,000 years ago created the beautiful, expanding shell of dust and gas seen here." Hold on, if it's 20,000 light years away, then we can't see this she'll, the light hasn't arrived yet!?

This Wikipedia article similarly says "The nebula contains around 15 M☉, all lost from the star around 10,000 years ago." Are we going to see this nebula when the light arrives at Earth in another 10,000 years, or did it happen 10,000 years before the photons showing the ring that we currently see on Earth were emitted?

Maybe relative time is handled a certain way in astronomical discussions, and this is just the first time I've noticed the issue with "NNNNN years ago"? -- Skierpage (talk) 06:14, 25 April 2021 (UTC)

Featured picture scheduled for POTD

Hello! This is to let editors know that File:A magnificent view of AG Carinae.jpg, a featured picture used in this article, has been selected as the English Wikipedia's picture of the day (POTD) for October 11, 2023. A preview of the POTD is displayed below and can be edited at Template:POTD/2023-10-11. For the greater benefit of readers, any potential improvements or maintenance that could benefit the quality of this article should be done before its scheduled appearance on the Main Page. If you have any concerns, please place a message at Wikipedia talk:Picture of the day. Thank you!  — Amakuru (talk) 19:47, 9 October 2023 (UTC)

AG Carinae is a luminous blue variable star in the constellation Carina. It is one of the most luminous stars in the Milky Way, although its great distance from Earth (20,000 light-years) and intervening interstellar dust mean that the star is not usually visible to the naked eye; its apparent brightness varies erratically between magnitude 5.7 and 9.0. Apparently in a transitional phase between a massive class-O blue supergiant and a Wolf–Rayet star, AG Carinae is highly unstable and suffers from erratic pulsations, occasional larger outbursts, and rare massive eruptions. The star is surrounded by a nebula of ejected material at a distance of 0.4 to 1.2 parsecs (1.3 to 3.9 light-years). The nebula contains around 15 solar masses of material, all lost from the star around 10,000 years ago. This photograph of AG Carinae and its surrounding nebula was taken by the Hubble Space Telescope in 2021, as one of its anniversary images.

Photograph credit: NASA, ESA and the Space Telescope Science Institute

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