Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

What is Webb observing now?

spacetelescopelive.org

Post reply on HN
Print view View original

41–50 of 76 posts

Re: What is Webb observing now?

#41

Post by privong »

regularfry wrote: post #4

If I zoom in, I see a reddish mottled pattern. Is that sensor noise, background radiation, or something else? Similarly, if I zoom out to 30.39 angular degrees, there's a similar-ish green mottled pattern that's very prominent. What's that? It looks like it's got linear features, which might be a stitching artefact of some sort, maybe?

> If I zoom in, I see a reddish mottled pattern. Is that sensor noise, background radiation, or something else?

I assume you mean the pattern that is distributed across the general image? That's noise in one of the three filter images used to make the color image. 2MASS imaged in the J, H, and Ks filters (likely mapped to blue, green, and red, respectively). It could be that the choice of stretch is emphasizing the noise in that filter a bit more. Alternately, the noise there could be a bit higher (at the long wavelength end, Ks starts to cover a part of the spectrum where there's appreciable emission from a ~300K blackbody, i.e., the general temperature of things Earth).

> Similarly, if I zoom out to 30.39 angular degrees, there's a similar-ish green mottled pattern that's very prominent. What's that? It looks like it's got linear features, which might be a stitching artefact of some sort, maybe?

Perhaps regions where the image was made using only the H band from the 2MASS survey?

Re: What is Webb observing now?

#42

Post by privong »

jofer wrote: post #37
regularfry wrote: post #4

If I zoom in, I see a reddish mottled pattern. Is that sensor noise, background radiation, or something else? Similarly, if I zoom out to 30.39 angular degrees, there's a similar-ish green mottled pattern that's very prominent. What's that? It looks like it's got linear features, which might be a stitching artefact of some sort, maybe?

I'm not an astronomer, but I believe the "mottled red" features are distant objects that are redshifted. Note that they're almost all red no matter where you zoom in. That's the evidence that space is expanding in a nutshell.

Distant objects do tend to look redder because of redshift, but the mottled pattern is a bit too regular to all be distant galaxies. It's more likely to be the noise in the data used for the red channel (likely the infrared Ks filter).

Re: What is Webb observing now?

#44

Post by wolverine876 »

Cthulhu_ wrote: post #17
jazzsouff wrote: post #14

Earlier quoted context omitted.

The post WW2 cold war is what pushed our understanding of space. So actually modern politics helped with that.

But once the space race to the moon was won - and all major powers had proven they are capable of producing ICBMs - it feels like the energy and financing just went out of it. There's no more political or military gain to be had from space exploration so governments only put in a token amount, and there's only limited commercial gain from e.g. telecom, mapping and navigation, but that's all focused on earth itself. T…

> But once the space race to the moon was won - and all major powers had proven they are capable of producing ICBMs - it feels like the energy and financing just went out of it.

Quite a few things have been done since then, including the JWST, all the other space telescopes, helicopters on Mars, visits to every planet in our solar system system, ...

Re: What is Webb observing now?

#45

Post by ianburrell »

skybrian wrote: post #39

I’m getting the impression that some people don’t know what they’re looking at. It says “Background: Two Micron All Sky Survey” which you can read about here [1]. This is not a live image. It’s just showing you where it’s pointing, which isn’t so meaningful for most of us. (It’s random-looking stars.) You can read interesting details about the current observation at the top, though. Currently: * A census of high-reds…

Webb won't ever provide a recent view since the images belong to the research group and are only made public when the results are released.

Also, Webb can't provide a video feed since it is taking long exposures, and probably only sends results back to Earth when image is finished. The images are in the infrared and only look good when processed.

Re: What is Webb observing now?

#46

Post by basil-rash »

ianburrell wrote: post #45
skybrian wrote: post #39

I’m getting the impression that some people don’t know what they’re looking at. It says “Background: Two Micron All Sky Survey” which you can read about here [1]. This is not a live image. It’s just showing you where it’s pointing, which isn’t so meaningful for most of us. (It’s random-looking stars.) You can read interesting details about the current observation at the top, though. Currently: * A census of high-reds…

Webb won't ever provide a recent view since the images belong to the research group and are only made public when the results are released. Also, Webb can't provide a video feed since it is taking long exposures, and probably only sends results back to Earth when image is finished. The images are in the infrared and only look good when processed.

> only look good when processed

Ehh. I personally can’t stand all the post processing folks love to make their results look “magazine ready”. I think the most minimal transformation possible to map the data into 0xRRGGBB would look the best, ideally with a simple standardized algorithm that doesn’t allow for any “artistic license”.

Re: What is Webb observing now?

#48

Post by sentrysapper »

This is amazing. I navigated back to some previous targets and saw what looks like some kind of astronomical event, blue clusters lining up to some kind of explosion. Can anyone explain what Webb is seeing to the left of its target here?

https://spacetelescopelive.org/webb?obsId=01HTJT20DRPEDT9DQN...

Re: What is Webb observing now?

#49

Post by _trampeltier »

basil-rash wrote: post #46
ianburrell wrote: post #45

Earlier quoted context omitted.

Webb won't ever provide a recent view since the images belong to the research group and are only made public when the results are released. Also, Webb can't provide a video feed since it is taking long exposures, and probably only sends results back to Earth when image is finished. The images are in the infrared and only look good when processed.

> only look good when processed Ehh. I personally can’t stand all the post processing folks love to make their results look “magazine ready”. I think the most minimal transformation possible to map the data into 0xRRGGBB would look the best, ideally with a simple standardized algorithm that doesn’t allow for any “artistic license”.

IR pictures would be not RGB, just black/white (or whatever palette you like). But yes, it would be possible. For ex. from Flir Thermal cameras, you also can output the image just as spreadsheet. You can even choose the values as temperature (which is calculated) or just as energy (what the sensor gets).

Re: What is Webb observing now?

#50

Post by sneak »

basil-rash wrote: post #46
ianburrell wrote: post #45

Earlier quoted context omitted.

Webb won't ever provide a recent view since the images belong to the research group and are only made public when the results are released. Also, Webb can't provide a video feed since it is taking long exposures, and probably only sends results back to Earth when image is finished. The images are in the infrared and only look good when processed.

> only look good when processed Ehh. I personally can’t stand all the post processing folks love to make their results look “magazine ready”. I think the most minimal transformation possible to map the data into 0xRRGGBB would look the best, ideally with a simple standardized algorithm that doesn’t allow for any “artistic license”.

I encourage you to try some raw file photography and processing. A bitstream from a sensor is not an image and there is no “correct” or “accurate” image from a captured signal.

Think of it like using a linear or log scale for a chart axis: neither is “more correct”, neither is taking “artistic license”.

Post reply on HN