APOD: The Tarantula Zone (2024 Mar 08)

[APOD Robot]

The Tarantula Zone

Explanation: The Tarantula Nebula, also known as 30 Doradus, is more than a thousand light-years in diameter, a giant star forming region within nearby satellite galaxy the Large Magellanic Cloud. About 180 thousand light-years away, it's the largest, most violent star forming region known in the whole Local Group of galaxies. The cosmic arachnid sprawls across this magnificent view, an assembly of image data from large space- and ground-based telescopes. Within the Tarantula (NGC 2070), intense radiation, stellar winds, and supernova shocks from the central young cluster of massive stars cataloged as R136 energize the nebular glow and shape the spidery filaments. Around the Tarantula are other star forming regions with young star clusters, filaments, and blown-out bubble-shaped clouds. In fact, the frame includes the site of the closest supernova in modern times, SN 1987A, at lower right. The rich field of view spans about 2 degrees or 4 full moons in the southern constellation Dorado. But were the Tarantula Nebula closer, say 1,500 light-years distant like the Milky Way's own star forming Orion Nebula, it would take up half the sky.

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[Christian G.]

"were the Tarantula Nebula closer, say 1,500 light-years distant like the Milky Way's own star forming Orion Nebula, it would take up half the sky", plus we would see R136a 1 in lieu of Theta1 Orionis C. That would be quite the sight!

[Montana]

Yes, it would. But the earlier statement of its actual width in our sky of 2 degrees (4 full moons) appears incorrect. At a distance of 180,000 light years, each degree of sky captures approximately 3140 light years. Times two equals 6180 light years. The article previously stated the Tarantula Nebula was only 1000 light years across. That would only be about 2/3 of a full moon’s width.

[Chris Peterson]

Yes, it would. But the earlier statement of its actual width in our sky of 2 degrees (4 full moons) appears incorrect. At a distance of 180,000 light years, each degree of sky captures approximately 3140 light years. Times two equals 6180 light years. The article previously stated the Tarantula Nebula was only 1000 light years across. That would only be about 2/3 of a full moon’s width.

The statement is not that the nebula is 2° wide, but that the FOV of this image is 2° wide. But I don't think that is correct. The image appears to me to be about 30 arcminutes wide, or the apparent size of the Moon.

[johnnydeep]

Yes, it would. But the earlier statement of its actual width in our sky of 2 degrees (4 full moons) appears incorrect. At a distance of 180,000 light years, each degree of sky captures approximately 3140 light years. Times two equals 6180 light years. The article previously stated the Tarantula Nebula was only 1000 light years across. That would only be about 2/3 of a full moon’s width.

The statement is not that the nebula is 2° wide, but that the FOV of this image is 2° wide. But I don't think that is correct. The image appears to me to be about 30 arcminutes wide, or the apparent size of the Moon.

Yup. And if, as the text conjectured, it was only 1,500 ly away instead of 180,000, it would appear over 100x larger, or 100 full Moons, or 50°, which is fully a third of the 180°extent visible from horizon to horizon.

[Ann]

The Tarantula Zone. Credit: Robert Gendler, Roberto Colombari,
Hubble Tarantula Treasure, ESO, JWST, amateur sources

I should have commented on this picture yesterday, but I didn't, because my sense of color was thrown off by it. Why is the Tarantula Nebula yellow? It could be that this picture is strongly bringing out the cyan-green OIII emission that is most certainly present in the Tarantula, and combined with the red color of hydrogen alpha that is most definitely present, the overall color may be yellow.

And, okay. I googled "Tarantula Nebula" and "pictures", and I got a lot of yellow-looking Tarantulas. Well, confession: I don't much like yellow color in emission nebulas, and if they are made to look yellow, I want an explanation for it.

Okay. One of the sources that Robert Gendler apparently used for his picture was an ESO image, and I think it was this one:

The Tarantula Nebula. Credit: ESO/IDA/Danish 1.5 m/R. Gendler, C. C. Thöne,
C. Féron, and J.-E. Ovaldsen

As you can see, the ESO image (where Robert Gendler was also involved) shows the Tarantula Nebula in the same shades of yellow as in the APOD, with some patches of rusty reddish and others of yellowish green. What I find most strange about it is that the ESO page tells us that this is an RVB image, essentially an RGB image. That would mean that the picture shows us what the Tarantula Nebula would look like to our eyes, if our eyes were many, many, many times more color-sensitive than they are. I don't believe that the Tarantula would look like that, if we could see its colors. Compare the ESO image with this RGB image by David Malin:

The Tarantula Nebula. Credit: David Malin/ Anglo-Australian Observatory.

---

David Malin's picture is quite old and somewhat lacking in resolution, but he was always very careful with his colors. He created his RGB images from the strength of the signals through his RGB filters, (actually, glass plates). So, if he got a strong signal through his red glass plate but weak signals through his green and blue glass plates, then he would show us a red object. And as you can see, his Tarantula nebula looks very red or reddish pink. The center is overexposed, both due to the brightness of the nebula, but also because appreciable amounts of green OIII are present there.

So while I can admire the details and resolution of both the ESO image and today's APOD, I still believe that David Malin's picture shows us what the Tarantula Nebula "really" looks like. Or what it would look like to our eyes, if we could see it in color.

You may or may not agree with me. But here, I'm being the stubborn Color Commentator.

Let me end by saying that Robert Gendler is a fantastic astrophotographer who is amazing at processing images. Many of his pictures are absolutely stunning. Just take a look at this picture of galaxy M106, where all the colors are "present and correct" and absolutely gorgeous-looking (and yes, the yellow hues here couldn't be more perfect and true):

M106. Credit: NASA, ESA, the Hubble Heritage Team (STScI/AURA), and R. Gendler (for the Hubble Heritage Team). Acknowledgment: J. GaBany

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That's stunning, Robert! You know I have the greatest admiration for you. It's just that you and I don't agree on the Tarantula Nebula.

Ann

[AVAO]

Tarantula-HST-ESO-Webb-SS1024[1].jpg

The Tarantula Zone. Credit: Robert Gendler, Roberto Colombari,
Hubble Tarantula Treasure, ESO, JWST, amateur sources

I should have commented on this picture yesterday, but I didn't, because my sense of color was thrown off by it. Why is the Tarantula Nebula yellow? It could be that this picture is strongly bringing out the cyan-green OIII emission that is most certainly present in the Tarantula, and combined with the red color of hydrogen alpha that is most definitely present, the overall color may be yellow.

And, okay. I googled "Tarantula Nebula" and "pictures", and I got a lot of yellow-looking Tarantulas. Well, confession: I don't much like yellow color in emission nebulas, and if they are made to look yellow, I want an explanation for it.

Okay. One of the sources that Robert Gendler apparently used for his picture was an ESO image, and I think it was this one:

tarantula[1].jpg

The Tarantula Nebula. Credit: ESO/IDA/Danish 1.5 m/R. Gendler, C. C. Thöne,
C. Féron, and J.-E. Ovaldsen

As you can see, the ESO image (where Robert Gendler was also involved) shows the Tarantula Nebula in the same shades of yellow as in the APOD, with some patches of rusty reddish and others of yellowish green. What I find most strange about it is that the ESO page tells us that this is an RVB image, essentially an RGB image. That would mean that the picture shows us what the Tarantula Nebula would look like to our eyes, if our eyes were many, many, many times more color-sensitive than they are. I don't believe that the Tarantula would look like that, if we could see its colors. Compare the ESO image with this RGB image by David Malin:

The Tarantula Nebula. Credit: David Malin/ Anglo-Australian Observatory.

---

David Malin's picture is quite old and somewhat lacking in resolution, but he was always very careful with his colors. He created his RGB images from the strength of the signals through his RGB filters, (actually, glass plates). So, if he got a strong signal through his red glass plate but weak signals through his green and blue glass plates, then he would show us a red object. And as you can see, his Tarantula nebula looks very red or reddish pink. The center is overexposed, both due to the brightness of the nebula, but also because appreciable amounts of green OIII are present there.

So while I can admire the details and resolution of both the ESO image and today's APOD, I still believe that David Malin's picture shows us what the Tarantula Nebula "really" looks like. Or what it would look like to our eyes, if we could see it in color.

You may or may not agree with me. But here, I'm being the stubborn Color Commentator.

Let me end by saying that Robert Gendler is a fantastic astrophotographer who is amazing at processing images. Many of his pictures are absolutely stunning. Just take a look at this picture of galaxy M106, where all the colors are "present and correct" and absolutely gorgeous-looking (and yes, the yellow hues here couldn't be more perfect and true):

M106. Credit: NASA, ESA, the Hubble Heritage Team (STScI/AURA), and R. Gendler (for the Hubble Heritage Team). Acknowledgment: J. GaBany

---

That's stunning, Robert! You know I have the greatest admiration for you. It's just that you and I don't agree on the Tarantula Nebula.

Ann

ThanX Ann

I think the intention for this picture was different. Constructing "WEBBLES" that work is an art when it comes to nebula, as optical and infrared come into direct contact with each other. At HUBBLE the dust filaments are dark and at WEBB they are often bright due to the hot gas. I have also tried this combo many times and have always despaired of it. If you also work with color layers, you often end up with an unappealing soup of randomly generated colors. If you take all of this into account, I think this panorama work in very high resolution was very successful and probably involved a lot of work...

Jac

P.S.: The link to the JWST images contained in the title is super useful: https://www.flickr.com/photos/nasawebbtelescope/albums

Add.: In true colors I would expect something like the following color palette for Rob's picture. However, the following image is a purely artistically distorted interpretation from different sources and can only give an idea, in which direction true colors could go.

Click to view full size image

[Ann]

I think the intention for this picture was different. Constructing "WEBBLES" that work is an art when it comes to nebula, as optical and infrared come into direct contact with each other. At HUBBLE the dust filaments are dark and at WEBB they are often bright due to the hot gas. I have also tried this combo many times and have always despaired of it. If you also work with color layers, you often end up with an unappealing soup of randomly generated colors. If you take all of this into account, I think this panorama work in very high resolution was very successful and probably involved a lot of work...

Jac

P.S.: The link to the JWST images contained in the title is super useful: https://www.flickr.com/photos/nasawebbtelescope/albums

Add.: In true colors I would expect something like the following color palette for Rob's picture. However, the following image is a purely artistically distorted interpretation from different sources and can only give an idea, in which direction true colors could go.

Click to view full size image

Thank you for that truly lovely picture of the Tarantula Nebula, Jac!

I can understand that it is very hard to create good-looking "WEBBLES" pictures, but for myself, I don't see much of JWST in the APOD. I can see a lot of the ESO image, but very little of JWST. Let's look at ESO, JWST and the APOD:

The Tarantula Nebula by ESO. Credit: ESO/IDA/Danish 1.5 m/R. Gendler, C. C. Thöne, C. Féron, and J.-E. Ovaldsen

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The Tarantula Nebula by JWST. Credit: NASA, ESA, CSA, STScI, Webb ERO Production Team

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https://apod.nasa.gov/apod/image/2403/T ... SS1024.jpg
The APOD. Credit: Processing: Robert Gendler, Roberto Colombari.
Data - Hubble Tarantula Treasury, European Southern Observatory,
James Webb Space Telescope, Amateur Sources

The most obvious contribution of JWST that I can see in the APOD is the blue color of central cluster R136.

Ann