I had a skim through the article in astronomy and astrophysics and I saw this
> The ring’s appearance in the images reconstructed with different algorithms (MiRA and IRBis) lends support to it being real. However, as Fig. E.2 shows, the location of the ring is just inside the side lobe of the dirty beam, and therefore we cannot entirely exclude the possibility that it might be an artifact of the image reconstruction inherent in the imperfect uv coverage. We refrain from further discussing this structure until we can confirm it with better uv coverage.
Which is interesting. So the ring may be an artifact.
Milky Way is about 100k LY in diameter, and this thing is 160k LY away, so it's not just closer to our particular neck of the woods than farther reaches of our own galaxy.
The picture is not if the star disk, but apparently of the huge dust cloud lit by a star in the middleof it.
Not a lot of information, just the photo and a paragraph blurb beneath it.
What I'm wondering is why the alleged "first" picture of this kind is of a star 160,000 light years away. There are hundreds of millions of stars in that distance range from us. I suppose there may be a reasonable explanation having to do with optimal visibility or something, but my intuition is completely failing here.
>The RSGs in the Large Magellanic Cloud (LMC) have the great advantage that their distances are much better known (50 kpc, Pietrzyński et al. 2013) compared to those of their Galactic counterparts. WOH G64 is the brightest RSG in the mid-infrared in the LMC, exhibiting a huge infrared excess with a high mass-loss rate on the order of 10−4 M⊙ yr−1 (Goldman et al. 2017). For this reason, it has been a subject of multiwavelength studies from the visible to the radio (e.g., van Loon et al. 1996; Levesque et al. 2009; Matsuura et al. 2016). Ohnaka et al. (2008) succeeded in spatially resolving the circumstellar dust environment of WOH G64 using the mid-infrared interferometric instrument MIDI at the Very Large Telescope Interferometer (VLTI).
Edwin Hubble [...] in 1925 [...] identified extragalactic Cepheid variable stars for the first time on astronomical photos of Andromeda [...] In 1943, Walter Baade was the first person to resolve stars in the central region of the Andromeda Galaxy.—https://en.wikipedia.org/wiki/Andromeda_Galaxy
The List of stars with resolved images (https://en.wikipedia.org/wiki/List_of_stars_with_resolved_im...) contains all those stars starts (unsurprisingly, on hindsight) with the Sun of which the first photograph was made in 1845; the next star to be visible on a photograph as a disk, not a point, was only made in 1993. I grew up in the knowledge that all stars (except for the Sun) are too far away for them being resolved; that became obsolete 30 years ago. Sadly, the list ends with 2014 and does not (yet?) include the new observation.
So yeah, even big, close stars like Betelgeuse (1995) are hard to resolve.
FWIW, for some context of “160,000 light-years away”, you can see pictures — taken by all levels of “backyard astronomers” — of the Large Magellanic Cloud (where WOH G64 is located) on AstroBin.
I had a skim through the article in astronomy and astrophysics and I saw this
> The ring’s appearance in the images reconstructed with different algorithms (MiRA and IRBis) lends support to it being real. However, as Fig. E.2 shows, the location of the ring is just inside the side lobe of the dirty beam, and therefore we cannot entirely exclude the possibility that it might be an artifact of the image reconstruction inherent in the imperfect uv coverage. We refrain from further discussing this structure until we can confirm it with better uv coverage.
Which is interesting. So the ring may be an artifact.
Milky Way is about 100k LY in diameter, and this thing is 160k LY away, so it's not just closer to our particular neck of the woods than farther reaches of our own galaxy.
The picture is not if the star disk, but apparently of the huge dust cloud lit by a star in the middleof it.
Not a lot of information, just the photo and a paragraph blurb beneath it.
What I'm wondering is why the alleged "first" picture of this kind is of a star 160,000 light years away. There are hundreds of millions of stars in that distance range from us. I suppose there may be a reasonable explanation having to do with optimal visibility or something, but my intuition is completely failing here.
from the article
>The RSGs in the Large Magellanic Cloud (LMC) have the great advantage that their distances are much better known (50 kpc, Pietrzyński et al. 2013) compared to those of their Galactic counterparts. WOH G64 is the brightest RSG in the mid-infrared in the LMC, exhibiting a huge infrared excess with a high mass-loss rate on the order of 10−4 M⊙ yr−1 (Goldman et al. 2017). For this reason, it has been a subject of multiwavelength studies from the visible to the radio (e.g., van Loon et al. 1996; Levesque et al. 2009; Matsuura et al. 2016). Ohnaka et al. (2008) succeeded in spatially resolving the circumstellar dust environment of WOH G64 using the mid-infrared interferometric instrument MIDI at the Very Large Telescope Interferometer (VLTI).
I guess it means "discernible single star outside our galaxy", because of course we can see distant galaxies.
The key term is 'close-up' here. Some context:
Edwin Hubble [...] in 1925 [...] identified extragalactic Cepheid variable stars for the first time on astronomical photos of Andromeda [...] In 1943, Walter Baade was the first person to resolve stars in the central region of the Andromeda Galaxy.—https://en.wikipedia.org/wiki/Andromeda_Galaxy
The List of stars with resolved images (https://en.wikipedia.org/wiki/List_of_stars_with_resolved_im...) contains all those stars starts (unsurprisingly, on hindsight) with the Sun of which the first photograph was made in 1845; the next star to be visible on a photograph as a disk, not a point, was only made in 1993. I grew up in the knowledge that all stars (except for the Sun) are too far away for them being resolved; that became obsolete 30 years ago. Sadly, the list ends with 2014 and does not (yet?) include the new observation.
So yeah, even big, close stars like Betelgeuse (1995) are hard to resolve.
- "The bright oval at the centre of this image is a dusty cocoon that enshrouds the star."
So, this isn't actually the emitting surface (photosphere) of the star, but a dust cloud about 10,000x larger than the star.
https://en.wikipedia.org/wiki/WOH_G64
the article in astronomy and astrophysics https://www.aanda.org/articles/aa/full_html/2024/11/aa51820-...
FWIW, for some context of “160,000 light-years away”, you can see pictures — taken by all levels of “backyard astronomers” — of the Large Magellanic Cloud (where WOH G64 is located) on AstroBin.
http://app.astrobin.com/search?p=eJy7mVCSWlFiq2rupGpkVJaYU5o...
What would the Milky Way look like on a planet in the Large Magellanic Cloud?
Over that way lies Mordor, under the all-seeing gaze of Sauron.