Euclid opens data treasure trove, offers glimpse of deep fields | Hacker News Reader

Euclid opens data treasure trove, offers glimpse of deep fields

esa.int

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How do these deep fields compare against other telescopes' deep fields (Hubble, JWST, &c.)?

edit: Trying to answer my own question: I understand they're around 10,000 times larger that Hubble's deep fields, each (three deep field zones)[a], with about 1/10th the sensitivity (limiting magnitude +27 in the optical bands[b], compared against Hubble's +29.1–30.3 [c]). Or that's the sensitivity it will reach, eventually; the one they've released now is still incomplete.

[a] https://en.wikipedia.org/wiki/List_of_deep_fields

[b] https://www.aanda.org/articles/aa/full_html/2025/03/aa51857-...

[c] https://www.aanda.org/articles/aa/full_html/2017/12/aa30833-...

See here: https://www.esa.int/Science_Exploration/Space_Science/Euclid... and here: https://bigthink.com/starts-with-a-bang/euclid-science-image...

Euclid is such a cool mission and this first tranche is merely 0.4% of what we'll eventually be getting. Fingers crossed!

Where did you hear the word tranche? People at work just started using it recently and I've been seeing it more as well. Why is this word trending right now?

https://en.wikipedia.org/wiki/Frequency_illusion

Heh, was looking up the wiki on the Baader Meinhoff phenomenon only to find out it sends you to your link. Guess that's an easier name to know it as :)

I’ve been hearing everyone talking about this phenomenon. Is it trending now?

It's not,

https://trends.google.com/trends/explore?q=tranche

https://xkcd.com/1053/

Well it's trending where I work, that's why I asked. I can search Teams and it doesn't come up at all, until the last month. Bam, tranche this and that instead of "group", which has been normal for 40 some years.

I started noticing it around the 2008/9 financial crisis because CDOs have tranches.

It‘s a normal word in German but i‘ve seen it used by ESA in English in the context of this data release.

Hopefully this is raw. Too much data is hidden behind obfuscated layers of "corrections"

Indeed. Was wanting to do some own analysis but realised all data I could find was ‘corrected’ :(

many such cases

This is the Q1 data release: https://www.cosmos.esa.int/web/euclid/euclid-q1-data-release This paper gives an overview: https://pubs.euclid-ec.org/public/coordinated_release/aussel... See figure 4 for an overview of the data processing.

The “non-quick” Data Release 1 is planned for October 2026: https://euclid.caltech.edu/page/data-release-timeline

When you are dealing with instrumentation, it is the device characteristics that obfuscate the signal and the calibrations that de-obsfucate it.

Who calibrates the calibrations?

While reading this announcement, two phrases came to my mind:

- "The sky! It's full of... stars!" from Isaac Asimov’s short story “Nightfall”

- "My God, it's full of stars!" from Arthur C Clarke’s novel “2001: A Space Odyssey”

And a follow up from the Krikkit species from the Hitchhiker's Guide:

- "It'll have to go"

In these videos zooming through the universe, is it just an optical illusion that seems to give a sense of depth and parallax motion, or is it something they've deliberately done to achieve it? I love the effect's subtlety and much less Ken Burns effect of making 2.5D in your face.

It’s an optical illusion. Probably because the human eye tries to interpret stars/galaxies of different brightness classes as sitting on different layers, and the speed perception is influenced by brightness (dimmer stars may slightly lag behind in human perception). It’s likely reinforced by the fact that the speed on the “canvas” isn’t uniform (the dots move faster the farer away they are from the center).

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